The study, published as an open-access paper in the journal Discover Plants, was led by Al Amin Talukdar and colleagues from Patuakhali Science and Technology University, with collaborator Md. Jamal Hossain of the Bangladesh Institute of Research and Training on Applied Nutrition. The team set out to answer a deceptively simple question: which part of the Chui Jhal vine, treated with which growth regulator, produces the strongest new plants? Traditional propagation of the species relies on stem cuttings, but success rates are slow and erratic, and the use of plant growth regulators in Bangladesh’s Chui Jhal cultivation has remained strikingly limited. That gap, the authors argue, represents a substantial untapped opportunity for a plant that carries both cultural weight and medicinal promise, with traditional applications ranging from asthma and bronchitis to digestive complaints.

To interrogate the question rigorously, the researchers designed a two-factor experiment at the university’s Germplasm Centre in Dumki Upazila, Patuakhali District, within Agro-Ecological Zone 13. Vine material was originally sourced from the Spices Research Sub-centre of the Bangladesh Agricultural Research Institute in Faridpur. The first experimental factor was the position of the cutting on the vine: the base section, roughly twelve months old; the middle section, about eight months old; and the tip section, approximately six months old. The second factor was a battery of ten growth regulator treatments, spanning a control with no regulator, the auxins indole-3-acetic acid and indole-3-butyric acid, and naphthalene acetic acid, each tested at 250 and 500 milligrams per litre, alongside three combinations pairing two regulators at 250 milligrams per litre each.

The cuttings themselves were prepared with careful attention to horticultural detail. Semi-hardwood segments were taken from healthy, disease-free mother vines about six months old, each cutting carrying three to five buds and measuring 20 to 30 centimetres in length with a diameter of 0.8 to 1 centimetre. The work was conducted in July, when ambient temperatures ranged from 26 to 33 degrees Celsius, rainfall averaged around 39 centimetres, and daylight lasted 13 to 14 hours. After being washed in distilled water and air-dried in shade for ten minutes, the lower 2.5 centimetres of each cutting, including the basal node, was immersed in its assigned treatment solution for just fifteen seconds before being planted in polybags filled with a sterilised 1:1 mixture of loamy soil and cow dung compost, steam-treated at approximately 100 degrees Celsius for 30 minutes.

The results, tracked at 30, 45, and 75 days after cutting, reveal a clear hierarchy among vine positions. Base cuttings achieved the highest survival at the first measurement, 79.99 percent, while the middle section led at the later intervals with 76.66 and 73.33 percent at 45 and 75 days respectively. Tip cuttings trailed consistently, falling to just 55.55 percent survival by the final assessment. When growth regulators entered the equation, the picture sharpened dramatically. Indole-3-butyric acid at 500 milligrams per litre, the treatment designated T5, drove survival in base and middle cuttings to a perfect 100 percent at multiple measurement points, with several other treatment combinations, including those involving 250 milligrams per litre of indole-3-acetic acid and 500 milligrams per litre of indole-3-butyric acid, also reaching complete survival. Untreated controls languished at the bottom of the range, dropping as low as 33.33 percent in tip cuttings.

Shoot development told a complementary story. Base cuttings produced the most leaves, rising from 1.90 per cutting at 30 days to 3.56 at 75 days, and generated the longest new shoots, reaching 6.27 centimetres by the final measurement. The 500 milligrams per litre indole-3-butyric acid treatment again proved the most effective leaf-promoting regime, while both 250 and 500 milligrams per litre of the same compound delivered standout shoot elongation. In the interaction analysis, base cuttings treated with 250 milligrams per litre indole-3-butyric acid achieved shoots up to 9.24 centimetres, and the corresponding leaf counts climbed to 5.33 per cutting by 75 days. The authors note that these findings echo earlier work on long pepper, in which auxin treatments stimulated cell division and stem elongation, accounting for greater leaf production and shoot length in treated cuttings.

Root architecture, arguably the most critical determinant of a cutting’s fate, showed its own subtle positional preference. Middle-section cuttings produced the highest root counts, averaging 22.86 roots per cutting by 75 days compared with 22.36 for base cuttings and 21.33 for tips. At the treatment level, 500 milligrams per litre of indole-3-butyric acid again dominated root number, while 250 milligrams per litre of the same compound produced the longest roots. The interaction data were striking: middle cuttings treated with 500 milligrams per litre indole-3-butyric acid yielded up to 39 roots per cutting, while base cuttings with 250 milligrams per litre indole-3-butyric acid extended roots to 9.38 centimetres. Control combinations, by contrast, produced as few as 2 to 3 roots per cutting early in the trial, underscoring the magnitude of the growth regulator effect.

The physiological explanation for the positional differences, the researchers suggest, lies in the internal chemistry of the vine itself. Base and middle sections contain greater carbohydrate reserves, richer nutrient content, more mature tissues, and higher concentrations of endogenous auxins and rooting cofactors, all of which support the initiation and development of adventitious roots. Tip cuttings, composed of younger, actively growing tissue, carry comparatively lower nutrient reserves and a different hormonal balance that limits their rooting response. This framework aligns with a broader body of literature on adventitious rooting, in which the interplay between stored carbohydrates, current photosynthesis, and hormonal signalling determines whether a severed stem segment commits to forming roots. The consistency of the indole-3-butyric acid advantage across survival, leaf production, root number, and root length suggests the compound is effectively supplementing the vine’s own auxin pool at the precise moment of greatest need.

The practical implications extend well beyond the laboratory. The authors conclude that base and middle vine sections treated with 500 milligrams per litre of indole-3-butyric acid represent the most suitable protocol for Chui Jhal propagation and recommend the approach for commercial-scale production and sustainable cultivation in Bangladesh. For farmers in Khulna and beyond, whose harvests currently depend on slow and unpredictable conventional cuttings, a fifteen-second dip in an inexpensive auxin solution could meaningfully compress the timeline from planting to harvestable stems and roots. The team is candid about the study’s limitations, noting that it was conducted at a single location over a single season, and they call for replication across different regions, seasons, and environmental conditions before definitive recommendations can be issued. Even so, the findings mark a significant step toward securing the future of one of South Asia’s most distinctive spices, a vine whose value has always been recognised at the dinner table and may now, at last, be matched in the nursery.

Subject of Research: Vegetative propagation of Piper chaba vine cuttings using plant growth regulators

Article Title: Response of Chui Jhal (Piper chaba) vine cuttings to plant growth regulators

Article References: Talukdar, A. A., Robbani, M., Hossain, M. J., Chowdhury, M. N. U., & Islam, M. S. (2026). Response of Chui Jhal (Piper chaba) vine cuttings to plant growth regulators. Discover Plants, 3(1), Article 430. https://doi.org/10.1007/s44372-026-00906-4

Image Credits: AI Generated

DOI: 10.1007/s44372-026-00906-4

Keywords: Chui Jhal, Piper chaba, plant growth regulators, indole-3-butyric acid, vegetative propagation, vine cuttings, adventitious rooting, auxins, Bangladesh, horticulture, survivability, spice crops

The research team, led by Irshad Ahmad Bhat together with Khushboo Guleria, Anamika Kumari, Sajida Banoo, Zahoor A. Kaloo and Mudasir Fayaz, collected fresh rhizomes in May 2022 from wild populations at Gulmarg and Aharbal in Jammu and Kashmir, regions the study describes as part of a recognized biodiversity hotspot. Voucher specimens were verified and deposited in the herbarium of the Centre for Biodiversity and Taxonomy at the University of Kashmir. The broader context is sobering: the Kashmir Himalaya alone harbours roughly 1,123 medicinal plant species, and an estimated 15,000 medicinal plant species worldwide now face extinction risk as demand for plant-derived therapies outpaces natural supply.

The core of the vegetative propagation work involved slicing rhizomes lengthwise into segments, sterilizing them in a 2 percent Bavistin fungicide solution, and then soaking the pieces for 48 hours in different plant growth regulators before planting them in pots. The hormones tested included gibberellic acid (GA3), the synthetic auxin indole-3-butyric acid (IBA), the cytokinin benzylaminopurine (BAP) and the aromatic cytokinin meta-topolin, each at 50, 100, 150 and 200 parts per million, alongside untreated controls. The results were striking. Cuttings treated with 150 ppm GA3 sprouted at a rate of 83.34 percent, compared with just 25 percent in untreated controls, and sprouted fastest, in an average of only 20.75 days.

Gibberellin treatment did far more than speed germination. GA3 at 150 ppm produced plants with an average of 44.75 leaves per plant, a shoot length of 16.6 centimetres and a rhizome length of 9.5 centimetres, all significantly higher than the control group. The authors explain that gibberellins are known to accelerate the transport of cytokinins to developing buds and to modify carbohydrate metabolism, which helps explain the vigorous sprouting and organ development observed. Interestingly, meta-topolin failed entirely to stimulate rhizome sprouting, underscoring how species-specific hormone responses can be and why empirical optimization is essential before any conservation program scales up.

Because what a cutting grows in matters nearly as much as what it is dipped in, the team also tested thirteen different soil compositions mixing soil, sand, vermicompost, peat moss and pebbles. The winning combinations were a 1:1:1 blend of soil, sand and vermicompost and a 1:1:1 mix of soil, pebbles and vermicompost, both of which achieved a perfect 100 percent sprouting rate. The fastest sprouting occurred in the soil-pebble-vermicompost mix at 19.75 days. The authors attribute the success of these porous, organic-rich substrates to better aeration and drainage, conditions that mirror the rocky, well-drained alpine meadows where the species naturally grows, and note that vermicompost supplies slow-release nitrogen and phosphorus while boosting microbial activity in the rooting zone.

The second half of the study moved from the greenhouse to the sterile laboratory. Healthy nodal segments from polyhouse-grown donor plants were disinfected using six different chemical sterilization protocols, and the most effective protocol achieved a contamination rate of only 8.46 percent, minimal tissue necrosis of 2.84 percent and an explant survival rate of 93.14 percent. The study found that mercuric chloride worked best not alone but in combination with sodium hypochlorite, consistent with earlier findings in pomegranate, bitter gourd and gerbera. With clean cultures established, the explants were placed on Murashige and Skoog medium supplemented with varying concentrations of the cytokinins meta-topolin and thidiazuron (TDZ).

Cytokinin choice and dose proved decisive for shoot regeneration. Neither hormone induced any shoots at all in regulator-free control medium, indicating that endogenous hormone levels in the explant tissue are insufficient to trigger regeneration on their own. Responses rose in a concentration-dependent manner up to 3.5 milligrams per litre, where TDZ alone produced a 75 percent regeneration frequency with 5.33 shoots per explant, and meta-topolin alone achieved 72.25 percent with six shoots per explant. Pushing concentrations to 4 milligrams per litre actually reduced regeneration efficiency, a classic supra-optimal dose response. Even better results came from pairing cytokinins with auxins: the combination of 3.5 milligrams per litre TDZ with 1.25 milligrams per litre IBA delivered the study’s headline figure of 82 percent regeneration, six shoots per explant, shoots up to 6.41 centimetres long and the shortest induction period of just 19.33 days.

Perhaps the most technically interesting component involved inducing the plantlets to form micro-rhizomes in culture. Because the medicinal value of A. fragrans is concentrated in its rhizomes, wild harvesting is inherently destructive, so producing rhizomes in vitro offers a way to supply raw material without touching wild populations. When shoots were transferred to medium containing the auxin naphthalene acetic acid (NAA), rhizome formation followed a clear dose response, peaking at 1.5 milligrams per litre NAA with a 71.45 percent induction rate, rhizomes averaging 6.02 centimetres, and the shortest induction time of 35.73 days. No rhizomes formed in regulator-free medium or at the highest NAA dose, reinforcing the narrow window of effective concentration.

The final bottleneck, and often the graveyard of micropropagation protocols, is hardening, the transition of fragile laboratory plantlets to ordinary greenhouse life. Here the team washed agar from plantlets bearing well-developed micro-rhizomes, moved them first into vermiculite under high humidity, and then into pots of soil, sand and vermicompost. Three quarters of the plantlets survived, and, crucially, no visible phenotypic differences appeared between the laboratory-raised plants and their wild relatives. The authors candidly acknowledge one limitation: molecular markers such as ISSR or RAPD were not used to confirm clonal fidelity at the genetic level, so hidden somaclonal variation cannot be fully ruled out. The regenerated plants were eventually transferred to a prepared plot at the Kashmir University Botanical Garden in June.

Taken together, the protocols offer a dual pathway forward: fast, cheap field multiplication of elite clones via GA3-treated rhizome cuttings in vermicompost-enriched soil, and a high-throughput tissue culture system for producing disease-free, genetically uniform planting stock at industrial scale. Both routes circumvent the species’ bottleneck of slow, unreliable seed germination and directly reduce pressure on wild populations whose rhizomes are currently harvested destructively. The authors argue the framework is readily transferable to other endangered Himalayan medicinal plants and set out the next research frontier: scaling up root biomass in culture, applying elicitation strategies to boost secondary metabolite production, and building the phytochemical and pharmacological database the species still lacks, so that its therapeutic compounds can eventually be standardized and clinically validated without costing the species its place on the mountain.

Subject of Research: Optimization of vegetative propagation and in vitro micropropagation protocols for the endangered Himalayan medicinal plant Aquilegia fragrans

Article Title: Optimization of vegetative propagation and micropropagation protocols for the conservation and large-scale cultivation of Aquilegia fragrans Benth

Article References: Bhat, I. A., Guleria, K., Kumari, A., Banoo, S., Kaloo, Z. A., & Fayaz, M. (2026). Optimization of vegetative propagation and micropropagation protocols for the conservation and large-scale cultivation of Aquilegia fragrans Benth. Discover Conservation, 3(1), Article 30. https://doi.org/10.1007/s44353-026-00099-7

Image Credits: AI Generated

DOI: 10.1007/s44353-026-00099-7

Keywords: Aquilegia fragrans, micropropagation, vegetative propagation, gibberellic acid, plant tissue culture, thidiazuron, meta-topolin, rhizome cuttings, medicinal plants, Kashmir Himalaya, plant conservation, vermicompost