The researchers used an integrated sequencing strategy combining PacBio HiFi sequencing, Illumina short reads and Hi-C technology. They generated chromosome-scale assemblies for Sicyos angulatus, Echinocystis lobata and Melothria pendula, with total genome sizes of 597.41 megabases, 629.27 megabases and 276.42 megabases, respectively. Scaffold N50 values were 50.69 Mb, 32.59 Mb and 22.38 Mb, while BUSCO completeness scores exceeded 98% for all three assemblies.

Comparative analysis encompassing 26 Cucurbitaceae species showed that lineage-specific dynamics of long terminal repeat retrotransposons were the primary correlate of genome-size variation. The researchers report that most insertion events occurred within the past two million years. They also detected a whole-genome duplication event confined to the tribe Sicyoeae, supported by markedly younger Ks peaks in S. angulatus and E. lobata.

Gene-family analysis identified different lineage-specific expansions in the three species: signal transduction and stress-response genes in S. angulatus, carbohydrate-metabolism and protein-synthesis components in E. lobata, and secondary-metabolite biosynthesis pathways in M. pendula. These are genomic associations rather than demonstrated causes of invasive behavior. The available abstract does not provide functional experiments establishing that the expanded gene families or other genomic features confer invasiveness traits, and it explicitly calls for functional validation.

Subject of Research: Comparative genomics of three invasive Cucurbitaceae species

Article Title: Chromosome-level genomes of three invasive Cucurbitaceae species provide insights into genomic features associated with invasiveness

Article References: Zhang, Y., Fu, W., Yuan, Z., Sun, C., Song, Z., Wang, Z., & Zhang, G. (2026). Chromosome-level genomes of three invasive Cucurbitaceae species provide insights into genomic features associated with invasiveness. BMC Plant Biology. https://doi.org/10.1186/s12870-026-09750-w

Image Credits: AI Generated

DOI: 10.1186/s12870-026-09750-w

Keywords: Cucurbitaceae, plant invasiveness, chromosome-level genomes, retrotransposons, whole-genome duplication, gene-family evolution, comparative genomics, genome assembly, Chromosome-level, genomes, three, invasive

The review addresses three central questions: the trend of chromosome evolution in specific tribes and species based on available information, the correlation between chromosome numbers and ploidy or genome size in studied taxa, and the requirement of an exclusive cytogenetic catalogue for the cucurbit research community. Data were compiled following the classification of Schaefer and Renner (2011) after consultation of books, chromosome atlases, research articles, and public resources including the Chromosome Counts Database, the Index to Plant Chromosome Numbers, and the Plant DNA C-values database. This foundational approach ensures that the collated information reflects the most comprehensive cytogenetic picture currently available for the family.

Chromosome counts are currently available for 188 species, approximately 19 percent of the total, belonging to about 44 genera, roughly 46 percent, spread across 15 tribes. Within the understudied tribes, chromosome counts exist for only 42 species out of nearly 310, belonging to 17 genera out of approximately 44. The basal number ranges from x = 5 in Thladiantha to x = 15 in Zanonia. The most prevalent base number x = 12 is considered ancestral, followed by x = 11, 13, 14, and 10. Polyploidy has been abundantly reported in Gomphogyneae, while the dibasic condition is noticed in Momordica with x = 11 and 14. In Bryonieae, the X-Y sex determination system has been analysed in Bryonia as the model along with its sister genus Ecballium. Polyploidy is frequent in Bryonia, and natural tetraploids are known in two species of Trichosanthes while the majority remain diploids.

Benincaseae, the second largest tribe comprising 204 to 214 species in 24 genera, shows cytological reports in around 35 percent of species. The base number x = 12 is the prevalent condition, with dual base numbers noted in the widely studied Cucumis at x = 7 and 12. Molecular cytogenetics of Cucumis sativus has demonstrated the evolution of x = 7 from x = 12 within Benincaseae, a finding strongly corroborated by rDNA hybridization data and substantiated by genomic studies. The genus Cucumis is the largest in Benincaseae with 65 species, of which 39 have been studied cytogenetically. Among Cucumis species with x = 12, co-localization of 45S and 5S rDNA loci has been documented in 14 species including Cucumis melo, while the number of 45S sites is generally four, though it may extend to six or eight in some cases.

The review presents fresh karyotypes of seven agriculturally important Indian cucurbit species belonging to the tribes Benincaseae and Sicyoeae, generated through an enzymatic maceration and air-drying method followed by fluorochrome banding. Fresh and healthy roots from germinating seeds, seedlings, and underground root stocks were pretreated with 0.002 M hydroxyquinoline, fixed in 1:3 aceto-methanol solution, and digested in an enzyme mixture containing 1 percent Cellulase Onozuka RS, 0.75 percent Macerozyme R-10, and 0.15 percent Pectolyase Y-23 for 40 to 45 minutes at 37 degrees Celsius. Slides were stained with 2 percent Giemsa solution and subsequently with DAPI and CMA fluorochromes to reveal AT-rich and GC-rich heterochromatin respectively. Chromosome plates were observed under a Zeiss Axioscop 2 fluorescence microscope with images captured using a ProgRes MFscan camera.

The Indian species analysed include ridged gourd (Luffa acutangula, 2n = 26), sponge gourd (Luffa aegyptiaca, 2n = 26), wild Luffa echinata (2n = 26), snake gourd (Trichosanthes cucumerina ssp. cucumerina Anguina, 2n = 22), pointed gourd (Trichosanthes dioica, 2n = 22), ash gourd (Benincasa hispida, 2n = 24), and ivy gourd (Coccinia grandis, 2n = 24). Fluorochrome banding patterns facilitated comparative analysis across these species. The cultivated ridged gourd showed three CMA-positive satellite-bearing pairs, as in the wild Luffa echinata, while the sponge gourd has two satellited pairs. Luffa acutangula and Luffa echinata also showed distal DAPI bands, absent in Luffa aegyptiaca. The 11th, 12th, and 13th pairs are marker chromosomes in Luffa, while the 10th and 11th pairs are conserved CMA-positive satellited pairs in Trichosanthes.

Genome size information is available for 49 species, nearly 5 percent of the total, belonging to 15 genera. Among the species studied, genome sizes show 5.84-fold differences, while chromosome counts show nearly three-fold differences across the family. In the Indian Momordica species, significant interspecific genome size differences have been reported, with species differing 5.19-fold in their 2C values ranging from 0.72 to 3.74 picograms. Interestingly, the species with the lowest chromosome number, Momordica cymbalaria at 2n = 18, contained the highest nuclear DNA content among the four Momordica species examined. In Bryonieae, flow cytometric genome size of Bryonia shows a 2.2-fold increase over Ecballium. In Sicyoeae, 2C DNA content ranges from 1.49 to 2.32 picograms, indicating 1.55-fold differences. The highest 2C nuclear genome in Benincaseae is known in Benincasa hispida at 1.97 picograms, while the lowest is in Cucumis melo var. inodorus at 0.64 picograms.

Statistical regression analyses for 41 taxa, including 16 Indian taxa, revealed significant linear correlations between 2n chromosome number and total haploid chromosome length, between ploidy and genome size, and between ploidy and haploid chromosome length. An increase in ploidy or 2n number is linked with an increase in haploid chromosome length. However, there was no significant correlation between 2C genome size and chromosome numbers, suggesting that these foundational cytogenetic parameters may not reflect residual evidence of whole genome duplication events in Cucurbitaceae at present.

At the molecular cytogenetic level, the review identifies three types of nucleolus organizer regions based on rDNA hybridization patterns. Type I includes chromosomes with only non-colocalized 45S and 5S rDNA sites, found in seven species of Benincaseae, one species each from Cucurbiteae and Momordiceae, and two species of Sicyoeae. Type II shows colocalized 45S and 5S rDNA loci, either adjacent or distant but always on the same chromosome, found in one species each of Benincaseae, Sicyoeae, and Actinostemmateae. Type III is characterized by chromosomes with both non-colocalized and colocalized 45S and 5S rDNA loci, as in 14 species of Benincaseae and one species each of Sicyoeae and Thladiantheae. Distinct 45S rDNA sites are higher in number than 5S rDNA sites across the family, with distal 45S rDNA loci serving as conserved genomic landmarks while 5S rDNA loci remain relatively diverse.

The dramatic evolution of the Y chromosome was validated in karyotypes of Coccinia grandis, where the 45S rDNA sites enabled confirmation of nucleolus organizer regions in the 8th and 12th chromosome pairs containing distal GC-rich CMA-positive signals. Three closely related dioecious species of Coccinia accumulated Y chromosome repeats and displayed sex chromosome turnover. Strong centromeric CMA bands were observed in Coccinia grandis except on the Y chromosome, presenting the possibility that a specific centromeric satellite is a feature of centromeres in dioecious Coccinia species. The review concludes that attention to chromosome number and genome size information in the basal clades should be prioritized to infer ancient base numbers, and that fundamental and molecular cytogenetic parameters remain inevitable for genomic interpretation and for spotting genetic resources and relationships with wild relatives. The offline resource serves as an exclusive toolkit for research and breeding communities across the globe and opens scope for the future establishment of a web-based database on Cucurbitaceae cytogenetics.

Subject of Research: A critical review on cytogenetics of Cucurbitaceae with updates on Indian taxa

Article Title: A critical review on cytogenetics of Cucurbitaceae with updates on Indian taxa

Article References: Bhowmick, B. K., & Jha, S. (2022). A critical review on cytogenetics of Cucurbitaceae with updates on Indian taxa. Comparative Cytogenetics, 16(2), 93-125. https://doi.org/10.3897/compcytogen.v16.i2.79033

Image Credits: AI Generated

DOI: 10.3897/compcytogen.v16.i2.79033

Keywords: Cucurbitaceae, cytogenetics, chromosome evolution, genome size, karyotype, India, critical, review, updates, Indian, taxa, scientific research

The genus Sicyos is the most diverse lineage within the gourd family, Cucurbitaceae. Linnaeus established the genus in 1753 with three species, and the count has grown steadily ever since: 31 species were recognized by the end of the nineteenth century, roughly 40 by 1990, and recent estimates place the total at 64. Most of these are climbing annual herbs, and their natural range centers on southeastern North America, northern South America, and parts of southern and southeastern Australia. One member of the genus, Sicyos angulatus, carries a particularly unwelcome reputation. In its native range it is classified as a weed, and it has been listed among the five most noxious weeds in regions where standard weed control programs struggle to contain it. That pedigree alone makes its arrival in the Caucasus a matter of genuine concern for agronomists and ecologists alike.

Bur cucumber’s journey to the Old World began in the nineteenth century, when it was introduced to Europe as an ornamental plant. The first record of the species growing in the wild came from the Balkan Peninsula in 1927, and over the following decades it naturalized in moist habitats across central, southern, and southeastern Europe, including Austria, the Czech Republic, Hungary, Italy, Romania, and parts of Russia. From the second half of the twentieth century onward, its range expanded dramatically: the species has now been reported from Sweden, Croatia, Norway, France, the United Kingdom, Spain, Germany, Slovenia, and beyond, as well as from Korea, Japan, China, Siberia, Australia, the Caribbean islands, Turkey, Ukraine, and India. Historical accounts also placed the genus in the European part of the former Soviet Union, in the Dnieper River basin and along the Volga-Don Canal, although an early indication of the genus for the Caucasus was never confirmed by later botanists.

Against that backdrop, the Georgian discovery in 2012 was less a surprise than a confirmation of a slow-motion invasion already underway. The first specimens were found on agricultural areas in the Chorokhi River valley, and the extent and frequency of the populations suggested the species had been present for some time. Interviews with local residents filled in the missing history: people living near the river recalled first seeing the plant ten to twelve years earlier, initially in small numbers along the riverbanks before it gradually pushed into farmland. Taken together, the evidence points to the early 2000s as the likely period when the first individual specimens appeared in the Chorokhi Valley, meaning the vine had been quietly establishing itself for roughly a decade before science formally caught up with it.

What followed was a steady drumbeat of new records. In 2013, a single specimen was seen on the left bank of the Chorokhi near the village of Tkhilnari, in disturbed habitats and agricultural areas, and in 2014 the plant reached the Chorokhi Delta. By 2015, botanists had found specimens around the Korolistskali, Bartskhana, and lower Mejinistskali rivers. The species then jumped northward: in 2017 it appeared in Ozurgeti near the Nabzhuara River, in 2018 along the Sajavakho-Chokhatauri-Ozurgeti highway near the Supsa River and in maize fields, and in 2020 new populations emerged at the Gubazeuli River near the village of Nabeglavi. In 2021, small populations were recorded in Kobuleti around the Achkva River, alongside a remarkable invasion in the middle reaches of the Mejinistskali and Bartskhana basins. By 2022, the vine had reached the banks of the Rioni River, cementing its presence across the lowlands of Kolkheti.

Understanding why this plant succeeds so well begins with its architecture. Sicyos angulatus is an annual herbaceous vine that typically stretches four to ten meters, dying back completely each winter and regrowing from seed. In Georgia, researchers recorded stems reaching an extraordinary sixteen meters. The angular, hairy stem carries branched tendrils in groups of three or four, and the leaves are simple, five-lobed, and up to twenty-five centimeters across, borne on stout hairy stalks. The tendril mechanics are remarkable in themselves: when a tendril tip touches a support, it wraps around it, then twists into spirals that reverse direction, an unusual behavior known as perversion. The result is a spring-like anchor that lets the vine haul itself over virtually any plant it encounters, from alder trees in the Chorokhi Delta to citrus shrubs in commercial plantations.

The plant’s reproductive machinery is equally efficient. Bur cucumber bears separate male and female flowers on the same plant, with male flowers arranged in panicles and female flowers packed into spherical clusters of eight to twenty. Flowering in Georgia runs from mid-July to September or mid-October, with pollination carried out by bees and flies as well as by the plant’s own pollen. What appears at dispersal time to be a single spiky fruit is actually a cluster of individual fleshy fruits radiating from a central point, each one to two centimeters long, covered in sharp white prickles, and containing a single large brown seed that is never fully released from its casing. Those prickles are not merely decorative: they hook into animal fur, turning livestock and wildlife into unwitting seed couriers.

The numbers behind this strategy are staggering. A single plant can produce between 4,500 and 78,000 seeds in a season, and in Georgia those seeds germinate by the end of April, with germination continuing throughout the growing season. Field surveys in the invaded zone found dense populations averaging twelve to eighteen individuals per square meter on moist and wet soils, with average heights of six to eight meters and individual specimens reaching twelve to sixteen meters. The vines develop numerous side shoots, and coverage at invaded sites climbs to ninety to ninety-five percent, smothering every plant beneath them. Because the species reseeds itself prolifically and its seeds can germinate across an extended window, each growing season adds new ground to the invasion.

The consequences for Georgia’s agriculture and biodiversity are already visible, even if they have not yet been quantified. In maize fields and citrus plantations, the vine significantly reduces both the quality and quantity of harvests, and its spiny fruits cause skin irritation in people who handle them. Three species from two native genera of Cucurbitaceae had previously been recorded in Georgia’s natural flora, making bur cucumber a genuinely novel addition to the country’s plant life, one with no native competitors adapted to check it. The humid, mild climate of western Georgia appears tailor-made for the species, which grows, flowers, fruits, and matures seeds without apparent limitation, and its spread is concentrated precisely in the river valleys, wetlands, and farmland that define the region’s economy.

The authors of the new study are careful about what remains unknown. The effect of Sicyos angulatus on local biodiversity and on the regional economy has not yet been measured quantitatively, and the species’ full potential range within Georgia and the wider Caucasus is still an open question. What the ten-year record does establish is the trajectory: a fast-growing, intensely climbing annual that has adapted readily to local soil and climate, expanded its distribution every year since its arrival, and now threatens both agricultural lands and already disturbed natural communities. Whether bur cucumber becomes a manageable nuisance or a defining weed of the Kolkheti lowlands will depend on how quickly monitoring and control efforts catch up with a vine that has, so far, always been a step ahead.

Subject of Research: Distribution and invasion biology of the alien plant Sicyos angulatus in Georgia

Article Title: New distribution records of the alien plant – Sicyos angulatus L. ( Cucurbitaceae ) from Georgia

Article References: Mikeladze, I., & Bolkvadze, G. (2023). New distribution records of the alien plant – Sicyos angulatus L. (Cucurbitaceae) from Georgia. Caucasiana, 2, 9-13. https://doi.org/10.3897/caucasiana.2.e96039

Image Credits: AI Generated

DOI: 10.3897/caucasiana.2.e96039

Keywords: Sicyos angulatus, bur cucumber, invasive species, alien plants, Georgia, Cucurbitaceae, Chorokhi River, Kolkheti lowlands, agricultural weeds, plant morphology, biological invasion, field survey

The research team, led by cytogeneticists working with the enzymatic maceration and flame-drying method, faced a formidable technical challenge. Cucurbit chromosomes are notoriously small and look frustratingly similar under a conventional microscope, which has hampered chromosome identification since cytogenetic studies of the family began in the 1920s. To overcome this, the researchers germinated seeds from commercial suppliers in China, treated actively growing root tips with a chemical that arrests cell division at metaphase, and digested the cell walls with an enzyme cocktail of cellulase and pectolyase before flame-drying the preparations onto glass slides. The result was spreads of well-separated, clearly outlined mitotic chromosomes suitable for precise measurement.

The real magic came from two sequential labeling steps. First, the team applied CPD staining, a mixture of the fluorochromes propidium iodide and DAPI that simultaneously highlights GC-rich regions in red and AT-rich regions in blue. These bands mark heterochromatin, the densely packed, repetitive DNA that tends to cluster around centromeres and chromosome ends. Second, the researchers performed fluorescence in situ hybridization, or FISH, using a biotin-labeled probe for the 45S ribosomal RNA gene cluster, the tandemly repeated DNA that encodes the structural RNA components of ribosomes. The green fluorescent signals revealed exactly where these gene clusters sit on each chromosome, providing landmarks that distinguish otherwise identical-looking chromosomes.

The results revealed striking diversity hidden beneath superficial similarity. The diploid chromosome numbers ranged from 14 in cucumber to 40 in pumpkin, with watermelon, bitter gourd and bottle gourd carrying 22, melon and wax gourd carrying 24, and sponge gourd carrying 26. Despite these differences, all eight species possessed symmetrical karyotypes built from metacentric and submetacentric chromosomes, meaning their centromeres sit near the middle or slightly off-center. Metacentric chromosomes dominated the complements, accounting for nearly 87 percent of all chromosomes counted. According to Stebbins’ classic classification system, every karyotype fell into the most symmetric categories, 1A, 1B or 2A.

The heterochromatin patterns told a story of deep evolutionary divergence. Five species, including cucumber, melon, watermelon, bitter gourd and sponge gourd, showed GC-rich bands at their centromeres, while wax gourd, bottle gourd and pumpkin lacked them entirely. Cucumber stood out with additional GC-rich heterochromatin at its chromosome tips, a feature absent even in its close relative melon. Pumpkin displayed yet another pattern: after the FISH procedure, DAPI counterstaining revealed pericentromeric AT-rich bands on four chromosome pairs, a distinct type of heterochromatin that differs from both the GC-rich and canonical AT-rich classes. The researchers suggest that the centromeric GC-rich heterochromatin seen in most species is likely an ancestral feature of the subfamily, and that the three species lacking it may have lost the signal through a reduction in GC content after speciation.

The ribosomal DNA sites proved equally informative. FISH detected two 45S rDNA loci in five species and five loci in cucumber, sponge gourd and pumpkin, with most sites positioned at the terminal ends of chromosome arms. Pooling their data with previous surveys covering 58 cucurbit species, the authors found that roughly three quarters of all 45S rDNA loci in the family occupy terminal positions, consistent with the general pattern across flowering plants. Four of the eight crops studied, watermelon, wax gourd, bottle gourd and bitter gourd, shared the same configuration of two terminal rDNA loci, hinting at a close kinship that matches molecular phylogenies. The researchers speculate that the ancestor of the tribe Benincaseae, which includes many of these crops, carried exactly two terminal 45S rDNA sites.

Cucumber emerged as the star of the study. By combining the CPD banding pattern with the 45S rDNA signals, the team could unambiguously identify every one of its seven chromosome pairs, each with a unique fingerprint of red bands and green signals. This provides plant breeders and geneticists with a simple, reliable method for chromosome identification in a crop whose genome has already been fully sequenced. In pumpkin, by contrast, the size of the rDNA signals on one chromosome pair differed markedly between the two homologous copies, a sign that the accession analyzed was heterozygous at that locus, a reminder that even within a cultivar, genomes can vary.

To place the eight species in a quantitative framework, the researchers calculated four karyotype asymmetry indices, including the coefficient of variation of chromosome length, which measures differences in size between chromosomes, and the mean centromeric asymmetry, which captures variation in centromere position within chromosomes. A scatter plot of these two indices cleanly separated all eight species, with sponge gourd showing the most symmetric karyotype and melon and bottle gourd the most asymmetric by the intra- and interchromosomal measures respectively. A principal coordinate analysis based on six karyological parameters then grouped the species into two clusters that largely matched the relationships inferred from DNA sequence data, with watermelon, bottle gourd and bitter gourd clustering tightly together and pumpkin occupying the most isolated position.

The study also shed light on genome size evolution. Total chromosome length correlated strongly with nuclear DNA content across the eight species, with wax gourd carrying the largest genome and bitter gourd the smallest. Genome sequencing studies attribute these differences mainly to the accumulation of transposable elements rather than whole-genome duplication, with wax gourd’s large genome driven by a substantial load of LTR retrotransposons. Pumpkin, meanwhile, is the product of an ancient allotetraploidization event, and cucumber and melon evolved from a shared twelve-chromosome ancestor through inversions, centromere repositioning and chromosome fusions. Yet despite all this upheaval, karyotype symmetry remained remarkably stable across the family.

The authors conclude that multivariate karyotype asymmetry analysis deserves a place alongside molecular phylogenetics as a complementary tool for tracing chromosome evolution in Cucurbitaceae. For a family that supplies humanity with some of its most important vegetables, the ability to read chromosomes with fluorescent precision opens new avenues for breeders seeking to transfer disease resistance and fruit quality traits between related species, and for evolutionary biologists piecing together how a single ancestral genome diversified into the gourds, melons and squashes that now fill markets around the world.

Subject of Research: Comparative karyotype analysis of eight Cucurbitaceae crop species using fluorochrome banding and 45S rDNA FISH

Article Title: Comparative karyotype analysis of eight Cucurbitaceae crops using fluorochrome banding and 45S rDNA-FISH

Article References: She, C.-W., Jiang, X.-H., & He, C.-P. (2023). Comparative karyotype analysis of eight Cucurbitaceae crops using fluorochrome banding and 45S rDNA-FISH. Comparative Cytogenetics, 17(1), 31-58. https://doi.org/10.3897/compcytogen.v17.i1.99236

Image Credits: AI Generated

DOI: 10.3897/compcytogen.v17.i1.99236

Keywords: Cucurbitaceae, karyotype, fluorochrome banding, FISH, 45S rDNA, heterochromatin, cucumber, melon, watermelon, pumpkin, cytogenetics, genome evolution

The formal description, published in the journal PhytoKeys, rests on a combination of detailed morphological comparison and molecular phylogenetic analysis. Trichosanthes is one of the most species-rich genera in Cucurbitaceae, comprising roughly 100 species distributed from India and Sri Lanka through China, Japan, and Southeast Asia to Papua New Guinea, northern Australia, and the Pacific islands. Around 40 of those species occur in China, mostly in the south and southwest, and several, most famously Trichosanthes kirilowii, have long histories in traditional medicine. Yet the genus has also been a taxonomically challenging group, its boundaries repeatedly redrawn as accumulating names and extensive morphological variation forced successive revisions of its subgenera and sections.

What makes Trichosanthes metamorpha immediately striking is a suite of characters that, taken together, do not overlap with any known relative. Its stems are completely glabrous and marked with tiny black dots about the size of a pinpoint, roughly 0.1 millimeters in diameter, densest at the nodes. Its basal leaves are dark glaucous green with reflective white patterning, a feature not documented in any examined material of its two closest morphological relatives, Trichosanthes dunniana and Trichosanthes pubera. The petals bear very short, dentate fringes, only 2.0 to 2.5 millimeters long, that are incurled and relatively thick yet brittle, in sharp contrast to the long, filiform, flat, and flimsy fringes of 8 to 12 millimeters found in both comparison species. The mature fruit is orange-yellow rather than red, and the seeds are broadly ellipsoid, pale brownish gray, and smooth, lacking the lateral ridges of T. dunniana or the concave surface ornaments typical of T. pubera.

The species also displays pronounced ontogenetic variation in leaf morphology, the trait that inspired its name. Basal leaves are mostly three-lobed and carry the white patterns, while apical or youngest leaves are usually deeply five-lobed and lack patterning altogether. This coordinated change in the degree of lobing and variegation along the stem can serve as an auxiliary diagnostic character, and the authors note that the ecological or developmental drivers of this heteroblastic shift remain to be studied. In the field, the plant grows at 300 to 1200 meters elevation, beneath damp rock walls and on forested slopes in relatively cool and moist environments, often in mountainous cultivated fields where local farmers regard it as a weed that negatively affects citrus cultivation.

To resolve the vine’s taxonomic status, the team combined classical herbarium work with genome-scale sequencing. Type specimens and large numbers of non-type specimens of closely related species were examined on site at herbaria HIB, K, and PE, and through digitized collections including the Chinese Virtual Herbarium, JSTOR Global Plants, and the Global Biodiversity Information Facility. Measurements were taken using ImageJ software, and voucher specimens were deposited in the herbaria of the Wuhan Botanical Garden and the Institute of Botany of the Chinese Academy of Sciences. Leaf material collected in the field and dried in silica gel yielded total genomic DNA, which was sequenced as paired-end reads on an Illumina HiSeq 2000 platform. The complete plastome was assembled with GetOrganelle using a reference sequence of T. pubera subsp. rubriflos, annotated with GeSeq, and manually reviewed, while nuclear ribosomal DNA sequences were assembled through the same workflow.

Two datasets anchored the phylogenetic analysis. The first was a plastid coding sequence dataset comprising 67 protein-coding genes shared among all sampled plastomes, built from 39 accessions of the tribe Sicyeae, including 32 accessions of Trichosanthes plus the newly generated plastome of the new species. This dataset spanned 57,566 aligned positions, of which 89.8 percent were identical, with an overall pairwise sequence identity of 99.1 percent. The second was a concatenated three-locus dataset combining the nuclear ribosomal internal transcribed spacer (ITS), the plastid matK gene, and the rpl20-rps12 region, comprising 72 accessions and 2,177 aligned positions with 52.3 percent identical sites. Luffa, Hodgsonia, and Sicyos served as outgroups, following the methodology of earlier studies of the genus.

Maximum likelihood analysis with IQ-TREE and Bayesian inference with MrBayes recovered identical topologies from the cp-CDS dataset. Trichosanthes metamorpha was placed within T. sect. Involucraria, as sister to T. pubera subsp. rubriflos with bootstrap support of 78 percent and a Bayesian posterior probability of 0.99. In that same analysis, T. dunniana and T. reticulinervis formed a strongly supported clade, with 100 percent bootstrap support and a posterior probability of 1.00, outside this lineage and sister to sect. Foliobracteola. The three-locus dataset, analyzed after an incongruence length difference test found no significant conflict between the nuclear ITS and plastid partitions, again placed the new species within sect. Involucraria, though as sister to a broader clade that includes T. tricuspidata, T. pubera subsp. rubriflos, T. pubera var. fissisepala, T. inthanonensis, T. lepiniana, and T. bracteata, with weaker support. The authors conclude that the combined morphological and molecular evidence firmly supports recognition of the Yangshuo population as a distinct species, even if its precise sister relationship within the section remains uncertain.

The phylogenetic results carry broader implications for the classification of the genus. Both datasets recovered T. dunniana and T. reticulinervis as a strongly supported clade separated from the main sect. Involucraria lineage, a result that agrees with recent large-scale analyses based on whole plastome data suggesting that Trichosanthes may be paraphyletic, with multiple genera nested within it. Those earlier analyses, however, covered only nine of the eleven sections recognized in the current infrageneric framework, leaving species-level representation incomplete. The authors therefore argue that current generic boundaries and infrageneric classification warrant further evaluation and revision with more comprehensive sampling and integrated evidence, while noting that a formal reassessment of sectional boundaries lies beyond the scope of the present study.

Within sect. Involucraria, the new species fits the traditional sectional concept in its persistent probracts, relatively large glandular male bracts, fimbriate petals, and dark green pulp, but its orange-yellow mature fruits and strongly reduced petal fringes broaden the known morphological variation within the group. The notably shortened, thickened, and brittle petal fringes represent one of its most distinctive floral characters. Male flowers open before dawn and emit an odor reminiscent of mushrooms and citrus, suggesting a possible association with nocturnal pollination, as reported in other species of Trichosanthes. Long and elaborate petal fringes have been implicated in pollinator attraction, particularly in moth-pollinated species, so whether the strongly reduced and thickened fringes of T. metamorpha serve a comparable function or reflect a different pollination biology remains an open question requiring direct observation of floral visitors.

The species is currently known only from two localities, Shihuiyao and Chahualing in Yangshuo County, each supporting more than 40 individuals. Analysis of twenty georeferenced records in GeoCAT yielded an extent of occurrence of 20.288 square kilometers and an area of occupancy of 40 square kilometers, and following IUCN Red List criteria the species is provisionally assessed as Vulnerable, VU B1ab(v)+2ab(v). Roadside clearing practices such as herbicide spraying and plant harvesting are current anthropogenic threats, and although access to the surrounding mountain slopes is difficult and additional plants may remain undetected, the picture is complicated by the plant’s own biology: female individuals appeared to be rare in the surveyed populations, severed rootstock fragments resprout along roadsides, and natural mortality sources include fungal infection and root damage caused by pillbugs. Nymphs of the melon stink bug Megymenum brevicorne were observed feeding on stems and leaves, and male inflorescences strongly attract ants, which were commonly seen beneath most male bracts. Dense white fungal mycelia colonizing leaf litter around the root zone were frequently noted in robust flowering individuals, an ecological association whose significance, like so much else about this remarkable new vine, awaits further study.

Subject of Research: Discovery and phylogenetic placement of the new plant species Trichosanthes metamorpha (Cucurbitaceae) from Guangxi, China

Article Title: Trichosanthes metamorpha ( Cucurbitaceae ), a striking new species from Guangxi, China

Article References: Wang, R.-Z., Ran, Z.-H., Schaefer, H., Wang, S.-W., Wei, N., & Wang, Q.-F. (2026). Trichosanthes metamorpha (Cucurbitaceae), a striking new species from Guangxi, China. PhytoKeys, 280, 1-18. https://doi.org/10.3897/phytokeys.280.190832

Image Credits: AI Generated

DOI: 10.3897/phytokeys.280.190832

Keywords: Trichosanthes metamorpha, Cucurbitaceae, new species, Guangxi, Yangshuo, molecular phylogenetics, plastome, taxonomic delimitation, heteroblasty, conservation, sect. Involucraria, China

The formal description, published in the open-access journal PhytoKeys, rests on a substantial evidentiary base. The research team examined 56 herbarium specimens representing 41 unique collections of the unnamed taxon, held at herbaria in Nairobi, Kew, Missouri, Wuhan and Wageningen. The holotype, the single specimen that anchors the name, was collected in June 1957 by S. Rawlins at Witu in Kenya’s Lamu County and is deposited at the East African Herbarium in Nairobi, with an isotype at the Royal Botanic Gardens, Kew. In addition, the team studied roughly 140 digitized specimens of other Eureiandra species online, comparing the new plant against its closest relatives using both living material and dried collections, with measurements refined through image-analysis software.

Eureiandra is a small African genus of the gourd family comprising eight species, distributed mainly in tropical and subtropical eastern and southern Africa, with one species, E. balfourii, restricted to the island of Socotra. The genus sits within tribe Coniandreae of the subfamily Cucurbitoideae and is characterized by simple tendrils, five free petals, broad anther connectives, beaked fruits and dark, subglobose to ovate seeds. These features distinguish it from morphologically similar genera such as Coccinia. Despite its botanical interest, the genus has attracted little attention beyond a handful of taxonomic treatments, and its economic or ethnobotanical significance remains poorly understood, although the roots of the Socotran species are reportedly used in traditional medicine and crude extracts have shown some biological activity in preliminary pharmacological studies.

The new species is a climber reaching up to four meters long, rising from a tuberous rootstock that can measure up to 17 centimeters in diameter. Its annual herbaceous stems are nearly glabrous, with sparse hairs mainly restricted to the nodes, a subtle but taxonomically telling feature. The leaves are dark green and glossy, broadly ovate to reniform-cordate in outline and palmately divided into three to five lobes, with blades ranging from 6.6 to 18.7 centimeters long and 6.1 to 26.0 centimeters wide. Male flowers are borne in clusters of two to fourteen on short peduncles, with pale orange petals marked by darker centers, while female flowers are solitary or paired. The fruits are ovoid to ellipsoid, pale green with conspicuous white blotches, fleshy, and taper into a stout beak about 15 millimeters long. The seeds are oblong-elliptic, blackish brown with a pale raphe and a slightly fibrous testa.

What sets Eureiandra orientalis apart most clearly is its similarity to, and simultaneous divergence from, its presumed closest relative, Eureiandra fasciculata. The two species share annual herbaceous stems, palmately lobed leaves and female flowers with five staminodes, yet they differ consistently across a suite of vegetative and reproductive characters. E. orientalis has larger, darker, glossy leaves with hairs confined to the veins and margins, whereas E. fasciculata has smaller, paler leaves that feel rough or puberulous. The male inflorescences of the new species are shortly pedunculate, while those of E. fasciculata are solitary or in fewer-flowered clusters lacking a distinct peduncle. The petals are ovate rather than obovate, the fruits larger, at 6.5 to 11.5 centimeters long compared with 4.5 to 8.5 centimeters, and the seeds oblong-elliptic with indistinct margins and a fibrous testa rather than subglobose with a distinct margin and smooth surface.

Perhaps the most evocative difference lies in the species’ phenology, the timing of its life cycle events. In Eureiandra orientalis, the leaves are fully developed at flowering time, draping the vines in glossy green as the pale orange blossoms open. In Eureiandra fasciculata, by contrast, the stems are often leafless at anthesis, producing flowers on bare stems. The new species flowers from January to August, with peak activity coinciding mainly with the coastal long rains of March to June and adjacent months, and it may also respond to local rainfall at individual sites. Notably, its flowering does not correspond to the short rains of October to December. Fruiting begins toward the end of the long rains and continues through the dry season, a rhythm shaped by East Africa’s bimodal rainfall regime.

The species’ name, orientalis, refers to its eastern African distribution and honors the unpublished name used by Luke in 2005. It is currently known from the coastal lowlands of Kenya and Tanzania, with most records from Kilifi County in Kenya and the coastal forest areas of Dar es Salaam and Tanga in Tanzania. The plant occupies low elevations between sea level and 760 meters, growing commonly on rocky limestone or coral rag slopes, at the edges of coastal forests, and in the understory of semi-deciduous forest. The paratype collections trace a rich history of botanical exploration, from specimens gathered in the Usambara Mountains in the 1890s to recent field collections made in 2024 on limestone slopes near Kilifi, documenting the plant across more than a century of East African botany.

Conservation assessment offers a measure of reassurance, though not complacency. With 39 georeferenced occurrences across roughly 15 locations, an extent of occurrence of about 130,000 square kilometers and an area of occupancy of 148 square kilometers, the species has been evaluated as Least Concern under the IUCN Red List Categories and Criteria. Yet the authors caution that coastal forest at several localities is already being lost to agricultural clearance and to quarrying of coral rag and limestone for cement. These activities are ongoing and are likely to reduce some populations in the near term, meaning that remaining forest fragments require prompt monitoring and protection even though the species does not yet meet the thresholds for a threatened category.

The long interval between the taxon’s first recognition in 1967 and its formal description today highlights the incomplete documentation of plant diversity in East Africa, a pattern echoed by a series of previously overlooked gourd family species described from Kenya during the past decade, including members of the genera Peponium and Zehneria. The discovery also underscores the importance of the coastal forests of Kenya, Tanzania and northern Mozambique, a region widely recognized as a center of exceptional plant diversity and endemism that continues to reveal significant taxonomic novelties.

One question remains open: the phylogenetic position of Eureiandra orientalis within the genus has yet to be confirmed with molecular data. The authors note that morphology alone may not fully capture evolutionary history in understudied tropical lineages, and they call for future studies integrating expanded field sampling, herbarium revision and phylogenomic data to clarify species limits, relationships within Eureiandra and the biogeographic significance of this eastern African coastal lineage. For now, a plant that waited nearly sixty years for a name has finally claimed its place in the botanical record, a reminder of how much undiscovered diversity still clings to the fragments of East Africa’s coastal forests.

Subject of Research: Taxonomic description of a new gourd family species from East African coastal forests

Article Title: Eureiandra orientalis ( Cucurbitaceae ), a new species from Kenya and Tanzania

Article References: Wang, R.-Z., Ran, Z.-H., Schaefer, H., Luke, Q., Mollel, N. P., Kirika, P. M., Chapano, C., Yan, X., Wang, S.-W., Wei, N., & Wang, Q.-F. (2026). Eureiandra orientalis (Cucurbitaceae), a new species from Kenya and Tanzania. PhytoKeys, 280, 133-146. https://doi.org/10.3897/phytokeys.280.206680

Image Credits: AI Generated

DOI: 10.3897/phytokeys.280.206680

Keywords: Eureiandra orientalis, Cucurbitaceae, new species, Kenya, Tanzania, coastal forests, taxonomy, plant diversity, biodiversity hotspot, herbarium, East Africa, conservation

Gibberellins are a family of plant hormones that have shaped agriculture for decades. They drive stem elongation, seed germination, and, crucially for growers, fruit set and expansion. But hormones are only useful to a plant when they are present in the right amount at the right place and time, which means that both their production and their destruction must be carefully controlled. That is where the GA2ox family of enzymes comes in. These enzymes, known formally as gibberellin 2-oxidases, act as molecular brakes: they convert bioactive gibberellins into inactive forms, effectively lowering the hormone signal inside plant tissues. Since the first gibberellin 2-oxidases were molecularly cloned and functionally characterised in the late 1990s, researchers have recognised C19-gibberellin 2-oxidation as a major gibberellin inactivation pathway in flowering plants, with genetic studies in Arabidopsis confirming its central role in controlling hormone levels.

What remained unclear, until now, was how one particular GA2ox gene behaves during the development of a cucurbit fruit, and whether its activity differs between the distinct tissues that make up that fruit. Cucumber fruit is an ideal system for asking this question because it can be cleanly dissected into two compartments: the pulp, the inner fleshy tissue that surrounds the developing seeds, and the pericarp, the outer fruit wall that gives the fruit its structure and its commercial appearance. These two tissues do not mature in lockstep, and previous work on gibberellin oxidase gene families in cucumber had not examined their expression with this level of tissue resolution.

The research team, led by Wenjiao Wang of the College of Horticulture at Shanxi Agricultural University, with Xiaoning An and Yupeng Liu conducting the experiments and Zhiping Liu contributing phylogenetic and promoter analyses, sampled cucumber fruit of the ‘9930’ line at five carefully chosen time points: 0, 7, 14, 21 and 28 days after pollination. This sampling strategy spans the entire arc of early fruit development, from the moment of pollination through fruit set, rapid expansion, and the beginning of maturation. At each time point, the researchers separated the pulp from the pericarp, ensuring that any differences in gene activity between the two tissues could be detected rather than averaged away, as would happen if whole fruits had been ground up for analysis.

To quantify how actively CsGA2ox2 was being transcribed in each sample, the team used quantitative real-time PCR, a technique that measures the abundance of specific messenger RNA molecules with high sensitivity. The measurements were calculated using the 2^(−ΔΔCt) method, a standard approach that normalises the target gene’s signal against a stable reference gene, in this case the Actin gene designated LOC101215469. This normalisation is essential because the total amount of RNA and the overall transcriptional activity of a tissue can vary dramatically between developmental stages, and without a reliable internal reference, comparisons across time points and tissues would be meaningless.

The results revealed a clear and consistent pattern. CsGA2ox2 was transcribed at every developmental stage the researchers examined, but its activity was not uniform. Transcript abundance was low at 0 and 7 days after pollination, the earliest phases of fruit set and initial growth. By 21 days after pollination, transcript levels had increased significantly, suggesting that the gene’s gibberellin-deactivating function ramps up as the fruit transitions through its mid-development phase. Just as striking was the tissue bias: at all stages examined, CsGA2ox2 transcripts were consistently and significantly more abundant in the pulp than in the pericarp. In other words, the inner flesh of the cucumber fruit maintains a stronger gibberellin-braking signal than the outer wall throughout development, a pattern that hints at different hormonal economies operating in the two compartments.

Beyond the expression data, the team characterised the protein that CsGA2ox2 encodes using a battery of computational, or in silico, analyses. The gene specifies a protein of 342 amino acid residues that shares between 71.84 percent and 74.96 percent amino acid identity with GA2ox homologues from other cucurbit species, placing it firmly within the evolutionary lineage of gibberellin 2-oxidases in the Cucurbitaceae family. Structural predictions painted a picture of an unstable, hydrophilic, non-secretory protein, meaning it is predicted to function inside the cell rather than being exported, and its secondary structure is dominated by random coils, flexible regions of the protein chain that lack a fixed helical or sheet-like geometry. The researchers also predicted phosphorylation sites, locations on the protein where other enzymes could attach phosphate groups to modulate its activity, a common mechanism of post-translational regulation in plant signalling proteins.

Perhaps the most intriguing computational finding came from the gene’s promoter, the stretch of DNA upstream of the coding sequence that governs when and where the gene is switched on. The team annotated the promoter’s cis-acting elements, short DNA motifs that serve as binding sites for regulatory proteins, and found elements responsive to abscisic acid, to light, and to meristem activity. Abscisic acid is another major plant hormone, often acting in opposition to gibberellins, so the presence of abscisic acid-responsive elements suggests a potential point of cross-talk between the two hormonal pathways during fruit development. Light-responsive elements hint at possible environmental modulation of the gene’s activity, while meristem-responsive elements connect the gene’s regulation to the developmental programme of actively dividing plant tissues.

The authors are careful and explicit about the limits of what their data can show. All protein-level results presented in the study are computational predictions, and they provide no direct functional evidence about what the CsGA2ox2 protein actually does inside cucumber cells. The expression data themselves are descriptive and correlative: they show that the gene’s transcript accumulation is stage- and tissue-specific, with a marked bias toward the pulp, but they do not demonstrate that this pattern causes any particular aspect of fruit development. The study is explicitly framed as a foundation for future functional studies on gibberellin catabolism in Cucurbitaceae fruit development, and the authors state that no datasets were generated or analysed beyond those reported in the study itself.

Even so, the work fills a genuine gap. Gibberellin oxidase gene families have been catalogued and characterised in a growing list of crops, including potato, apple, grape, maize, litchi, marigold, pear, and wheat, where GA2ox-related genes underpin agriculturally important traits such as dwarfism, and recent multi-omics work has implicated the gibberellin biosynthesis gene CsGA20OX1 in hormone-mediated parthenocarpy of cucumber. By adding a tissue-resolved, time-course expression profile of CsGA2ox2 to this body of knowledge, the Shanxi team has provided breeders and molecular biologists with a candidate gene whose pulp-biased, developmentally regulated expression pattern makes it a compelling target for functional studies. If future experiments confirm that CsGA2ox2 shapes gibberellin levels specifically within the developing flesh of the fruit, it could inform strategies for modulating cucumber fruit texture, size, and maturation timing, traits that matter enormously in a crop grown intensively in greenhouses around the world.

Subject of Research: Stage- and tissue-specific expression of the gibberellin 2-oxidase gene CsGA2ox2 during cucumber fruit development

Article Title: Expression profiling of the gibberellin 2-oxidase gene CsGA2ox2 (Cucumis sativus L.) reveals stage- and tissue-specific transcript accumulation during fruit development

Article References: An, X., Liu, Y., Liu, Z., & Wang, W. (2026). Expression profiling of the gibberellin 2-oxidase gene CsGA2ox2 (Cucumis sativus L.) reveals stage- and tissue-specific transcript accumulation during fruit development. Molecular Biology Reports, 53(1), Article 1679. https://doi.org/10.1007/s11033-026-12796-6

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12796-6

Keywords: cucumber, CsGA2ox2, gibberellins, GA2-oxidase, fruit development, gene expression, qRT-PCR, bioinformatics, Cucurbitaceae, plant hormones, pericarp, pulp

The gourd family, Cucurbitaceae, is one of the most economically important lineages of flowering plants on Earth. According to the taxonomic framework used by the researchers, it comprises roughly 100 genera and 1,069 species distributed across temperate and tropical regions. Most members are prostrate or climbing herbs and shrubs equipped with spirally curled tendrils, the signature climbing organ that allows them to scramble over forest understorey vegetation. The family includes crops of global significance, and several species, among them Cucumis melo and Hodgsonia macrocarpa, are also used in traditional medicine across Asia. Yet the wild relatives of these cultivated forms are increasingly threatened, because overharvesting in natural habitats pushes many of them toward extinction.

Assam has a long but discontinuous history of botanical exploration. In the landmark Flora of Assam, published in 1938, Kanjilal and his co-workers reported five genera and 26 species with one variety of Cucurbitaceae from the state. Decades later, Barooah and Ahmed updated that picture, listing 37 species under 20 genera. After that, the authors note, there was a long gap in floristic and conservation work on the gourd family in Northeast India. That gap matters, because wild cucurbits are not merely botanical curiosities; they carry genetic traits such as disease resistance and drought tolerance that plant breeders may one day need for the crops that feed the world.

The study area itself is unusual. Bherjan-Borajan-Padumoni Wildlife Sanctuary is not a single block of forest but a combination of three distinct patches, Bherjan, Borjan and Padumoni, lying between latitudes 27 and 27.4 degrees north and longitudes 95 and 95.5 degrees east. The vegetation is classified as tropical wet evergreen rainforest, almost entirely closed under a continuous tree canopy. Despite its small size, the sanctuary shelters rare and endangered animals such as the Assamese macaque, the hoolock gibbon and the capped langur, along with notable birds including the streak-throated woodpecker, the greater yellownape, the lesser flameback and the osprey. Botanically, it hosts species such as the giant dipterocarp Dipterocarpus macrocarpus and the locally significant Ixora bawae.

To capture that diversity in a quantifiable way, the researchers laid three belt transects of 300 by 50 metres at random in each part of the sanctuary as permanent plots. Within each plot, five quadrats of 10 by 10 metres were randomly established for tree species, and inside those, two smaller quadrats of 5 by 5 metres captured shrubs, saplings and seedlings, while two quadrats of 1 by 1 metre recorded herbs. This nested phytosociological design allowed the team to sample every vertical layer of the forest, from the canopy down to the forest floor, where many climbing cucurbits begin their lives.

Specimens of all plant species encountered were collected together with photographs, and herbarium material was prepared using standard taxonomic methods. Voucher specimens were deposited at the herbarium of the North Eastern Institute of Ayurveda and Folk Medicine Research, each with a collection number and accession number. Identification was carried out by consulting the relevant literature and herbarium collections at Indian herbaria including ARUN, ASSAM, BSHC and CAL, and was confirmed through the original species descriptions, known as protologues, and images of type specimens held at CAL, E and K. Detailed morphological examination took place both in the field and in the laboratory, a double-check that is essential when a record claims to be new for a state.

The surveys, conducted between 2024 and 2025, yielded twelve species in ten genera of Cucurbitaceae from the sanctuary. The list reads like a catalogue of the family’s architectural range. Actinostemma tenerum, a slender climber with ovate to sagittate-ovate leaves and white flowers borne in racemes, fruits in small oblong-ellipsoid capsules. Coccinia grandis, the familiar ivy gourd, was found in semievergreen forest and along forest margins. Cucumis melo, the wild melon, crept through open forest areas, while Diplocyclos palmatus, with its palmately five-lobed leaves and globose indehiscent fruits, climbed through open woodland. Trichosanthes costata and Trichosanthes tricuspidata, both snake gourd relatives with elaborate white flowers and ribbed or oblong fruits, were recorded in mixed and evergreen forest respectively.

Two of the most spectacular finds are giants of the climbing world. Hodgsonia macrocarpa forms vines up to 20 to 30 metres long, with three-lobed leaves and enormous fruits reaching 15 to 18 centimetres in diameter, densely covered in grey hairs. Indofevillea khasiana, a robust branched climber recorded in the Borjan range, bears leathery, broadly ovate-cordate leaves up to 26 centimetres long and distinctive oblong fruits with a thick woody rind that hang in clusters on the stalk. The genus Thladiantha was represented twice, by T. cordifolia in evergreen forest and T. hookeri, whose stems can stretch 2 to 10 metres through the canopy. Luffa aegyptiaca, the wild luffa whose mature fruits become strongly fibrous, rounded out the inventory.

The headline discovery, Cucumis hystrix, is a monoecious scandent climber with angular, scabrous, hirsute stems and ovate to triangular-ovate leaves that are irregularly five-lobed. Its male and female flowers are both solitary in the leaf axils, with yellow corollas, and its ellipsoid-oblong fruits, 4 to 5 centimetres long, are covered in spine-like protuberances 2 to 4 millimetres long, the feature that gives the species its name. The plant was collected in the Bherjan range at about 130 metres above sea level, flowering and fruiting between August and January. A careful search of the literature and of herbarium specimens across Indian collections verified that the taxon had never been reported for Assam before. Its known distribution spans Meghalaya’s Garo Hills, Karnataka, Tripura, Nepal, Bangladesh, Myanmar, Thailand and southwest China, but within Assam it appears, so far, to be confined to this single sanctuary.

The conservation implications are stark. Of the 20 genera and 37 species recorded for Assam, the presence of 12 species and ten genera inside one small sanctuary is considered significant by the authors, and three of the species found there, Indofevillea khasiana, Thladiantha cordifolia and Thladiantha hookeri, are regarded as rare in the state. The sanctuary is under pressure from expanding tea gardens and oil fields, major anthropogenic drivers of habitat change in the region. The researchers argue that urgent conservation measures are needed, including the identification of prioritised areas for in-situ conservation within protected areas, so that wild gourds, including the newly confirmed spiny cucumber, can survive in the forest habitats where their genetic legacy has evolved over millennia.

Subject of Research: Floristic diversity of the gourd family Cucurbitaceae in a small Assam wildlife sanctuary, including a new state record

Article Title: Diversity of Cucurbitaceae Juss. in Bherjan-Borajan-Padumoni Wildlife Sanctuary, Assam, with Cucumis hystrix Chakrav. as a new addition to the state flora

Article References: Baro, D., & Bawri, A. (2026). Diversity of Cucurbitaceae Juss. in Bherjan-Borajan-Padumoni Wildlife Sanctuary, Assam, with Cucumis hystrix Chakrav. as a new addition to the state flora. Discover Plants, 3(1), Article 445. https://doi.org/10.1007/s44372-026-00894-5

Image Credits: AI Generated

DOI: 10.1007/s44372-026-00894-5

Keywords: Cucurbitaceae, Cucumis hystrix, Assam, Bherjan-Borajan-Padumoni Wildlife Sanctuary, floristic survey, plant taxonomy, biodiversity, new state record, conservation, Northeast India, wild crop relatives, herbarium

The review team searched four major databases, PubMed, Google Scholar, Scopus, and ScienceDirect, with no restrictions on publication date, casting the widest possible net for studies documenting how Zehneria species are used in traditional healing, what chemical constituents they contain, and what biological effects have been measured in the laboratory. The initial sweep returned 1,188 records. After removing 15 duplicates, the researchers screened titles and abstracts and then full texts against predefined inclusion and exclusion criteria, admitting only original research articles that reported ethnomedicinal, phytochemical, or pharmacological data. In the end, 40 studies survived the gauntlet and formed the evidence base for the final analysis, which was synthesized using a qualitative descriptive approach rather than statistical pooling, an appropriate choice given the heterogeneity of the underlying experiments.

What emerged from that synthesis is a portrait of a genus whose reputation in folk medicine is being progressively validated at the bench. Zehneria scabra, a twining herb recognized across large parts of Africa and Asia, stands out as by far the most extensively studied species of the group. Traditional practitioners have long employed it against infectious diseases, gastrointestinal complaints, inflammatory conditions, and skin ailments, and the review confirmed that this pattern of use is remarkably consistent across geographies and cultures. That consistency matters scientifically: when unrelated communities independently converge on the same plant for the same categories of illness, it often signals that the plant genuinely contains biologically active compounds rather than merely occupying a cultural niche.

The pharmacological evidence assembled in the review spans an unusually broad spectrum of activities. Experimental studies demonstrated antimicrobial effects against bacterial and fungal pathogens, antiplasmodial activity relevant to malaria, anti-inflammatory and antioxidant actions, wound-healing properties, antidiarrheal effects, and even insecticidal activity. Each of these endpoints maps directly onto a traditional use documented in the ethnomedicinal record, from the treatment of fevers and wounds to the management of diarrhea and skin infections. The alignment between folk indications and laboratory outcomes is the kind of ethnopharmacological convergence that drug discovery teams look for when deciding which natural products deserve deeper investigation.

Underpinning these biological effects is a rich and diverse phytochemistry. Phytochemical investigations of Zehneria species have revealed flavonoids, alkaloids, phenolic compounds, terpenoids, and triterpenoids, several classes of molecules with well-established pharmacological pedigrees. Flavonoids and other phenolics are frequently responsible for antioxidant and anti-inflammatory effects through the scavenging of reactive oxygen species and the modulation of inflammatory signaling pathways. Alkaloids have historically yielded some of medicine’s most potent agents, while triterpenoids are increasingly studied for antimicrobial and cytotoxic properties. Notably, the review reports that novel compounds with potential therapeutic relevance have been isolated from the genus, meaning that Zehneria is not merely a source of known chemical scaffolds but may harbor molecular structures not yet described in the wider literature.

The authors are careful, however, to flag a significant imbalance in the evidence base. Of all the species in the genus, the overwhelming majority of published work concentrates on Zehneria scabra, leaving its relatives largely unexamined in the laboratory. This concentration means that generalizations about the therapeutic potential of the genus rest heavily on a single species, and the review explicitly notes where conclusions are limited by this skew. For biodiversity and drug discovery purposes, that gap is tantalizing: closely related species often produce structurally similar but chemically distinct metabolites, and unstudied Zehneria species could contain compounds with activity profiles quite different from those of their well-known cousin.

Equally important are the translational caveats that the review lays out. Nearly all of the pharmacological data come from preclinical experimental models, in vitro assays and animal studies, rather than controlled trials in humans. The review’s authors call for standardization of extraction methods, a persistent problem in natural products research where different solvents, plant parts, and preparation techniques can yield extracts of wildly varying composition and potency. Without standardized extracts, results from different laboratories are difficult to compare, and reproducibility suffers. The authors also emphasize the need for rigorous safety and toxicity evaluations, since a compound that kills parasites or bacteria in a dish may also harm host cells at similar concentrations, and for properly designed clinical studies before any evidence-based therapeutic application can be recommended.

These limitations do not diminish the significance of the synthesis; they define the roadmap. The trajectory from ethnomedicinal observation to approved medicine typically runs through phytochemical characterization, bioassay-guided fractionation to identify the active molecules, pharmacokinetic and toxicological profiling, and finally clinical testing. Zehneria scabra has now cleared the first two stages with credible data, and the systematic review consolidates that progress in a form that other researchers can build on. The open-access publication, released on 8 September 2026 with a permanent DOI, ensures that the compiled evidence is freely available to research groups in the low- and middle-income countries where these plants actually grow, a small but meaningful correction to the historical pattern in which the medicinal knowledge of the Global South is validated and commercialized elsewhere.

There is also a conservation and cultural dimension to the findings. Plants used in traditional medicine are often harvested from the wild, and rising scientific interest can either support sustainable cultivation or accelerate overexploitation. Documenting the ethnomedicinal uses of Zehneria species, as this review does, preserves knowledge that is vulnerable to being lost as traditional healers age and as younger generations migrate to cities. At the same time, confirming pharmacological activity gives local communities and national authorities a scientific rationale for protecting both the plants and the habitats they depend on, and potentially for developing cultivated supply chains that benefit the communities who originated the knowledge.

For now, the message of the review is one of measured enthusiasm. The genus Zehneria, and Zehneria scabra in particular, has moved from anecdote to evidence, with 40 studies documenting a coherent story of traditional use, plausible bioactive chemistry, and demonstrable laboratory activity against pathogens, inflammation, oxidative stress, and impaired wound repair. What remains is the harder, more expensive work of isolating single active compounds, establishing dose-response relationships and safety margins, and testing standardized preparations in clinical settings. If those steps succeed, a vine that village healers have trusted for centuries could eventually contribute molecules to the modern pharmacopoeia, joining the long list of drugs, from artemisinin to aspirin’s derivatives, that began as folk remedies and ended as prescription medicines.

Subject of Research: Ethnomedicinal uses, phytochemistry, and pharmacological activities of the medicinal plant genus Zehneria (Cucurbitaceae), with emphasis on Zehneria scabra

Article Title: Therapeutic potential of the genus Zehneria (Cucurbitaceae): a systematic review of ethnomedicinal uses, phytochemistry, and pharmacological activities, with a predominant focus on Zehneria scabra

Article References: Gemechu, A. L., Diba, G., Mekuria, M. A., & Damissie, G. (2026). Therapeutic potential of the genus Zehneria (Cucurbitaceae): a systematic review of ethnomedicinal uses, phytochemistry, and pharmacological activities, with a predominant focus on Zehneria scabra. BMC Complementary Medicine and Therapies. https://doi.org/10.1186/s12906-026-05576-z

Image Credits: AI Generated

DOI: 10.1186/s12906-026-05576-z

Keywords: Zehneria, Zehneria scabra, Cucurbitaceae, ethnomedicine, phytochemistry, pharmacology, systematic review, natural products, antimicrobial, anti-inflammatory, traditional medicine, drug discovery