Asian Plant Research Journal

Breeding Techniques of Orchids, Role of Tissue Culture and Micropropagation in Mass Cultivation and Its Ecological Importance: A Review

Beauty Borah — 2026-04-15

Orchids (family Orchidaceae) are one of most diverse and largest family of flowering plants, with over 28,000 species globally. They have varied growth habitats (terrestrial, epiphytic, lithophytic, and saprophytic) and possess highly specialized flowers with longer life span. This makes orchids a valuable ornamental flower in the global floriculture sector. Due to increased commercial demand and insufficiency of conventional breeding methods, advanced techniques like mutational breeding, molecular marker-assisted breeding, transgenic breeding, and genome editing (CRISPR/Cas9) have been adopted to produce improved varieties with desired traits on a large scale.

Plant tissue culture and microprogation has transformed orchid propagation by permitting the bulk creation of uniform, disease-free plants through in vitro methods involving protocorm development from leaves, shoots, root tips etc. and somatic embryogenesis. The efficiency of propagation is significantly improved using synthetic seed technology. Due to the presence of phytochemicals and bioactive compounds, orchids are valuable not only as ornamental flowers but are also used in traditional medicine, culinary flavoring, perfumery, and pharmaceuticals.

Orchids also maintain a vital symbiotic relationship with mycorrhizal fungi, essential for seed germination and nutrient acquisition, highlighting their ecological dependence. They are sensitive to microenvironment, climate conditions, pollinators, mycorrhizal association and hence ecologically serve as bioindicator of forest health. However, overexploitation, habitat destruction, and climate change are posing a growing threat to orchids. Therefore, to guarantee their sustainable use and long-term survival coordinated conservation strategies such as habitat protection, community awareness, germplasm conservation, and advanced biotechnological approaches are crucial.

Impact of Wood Biochar Doses on Vegetative Growth of Cauliflower (Brassica oleracea var. botrytis) in Coastal Saline Soils of Bangladesh

Jannatul Ferdous — 2026-03-23

Background: Continuous cropping and intensive agricultural practices have led to the degradation of many productive soils, resulting in problems such as loss of organic matter and nutrients, drought stress, erosion, waterlogging, salinity, and soil compaction. Biochar has been reported to stimulate plant growth by improving soil structure, enhancing nutrient availability, and increasing soil water-holding capacity. Furthermore, the porous structure of biochar provides a favorable habitat for microorganisms such as bacteria, actinomycetes, and arbuscular mycorrhizal fungi, thereby enhancing soil microbial activity

Aims: The present study evaluates the effects of varying wood biochar doses on growth parameters (plant height, leaf number, leaf breadth, and leaf length) of cauliflower in coastal Bangladesh, and assess its potential as a soil amendment for challenging environments.

Study Design: Randomized Complete Block Design with three replications.

Place and Duration of Study: Noakhali Science and Technology University Campus, Noakhali, Bangladesh, from January to March 2022.

Methodology: Five treatments were tested: T₀(0 ton/ha, control), T₁ (2 ton/ha), T₂(4 ton/ha), T₃ (6 ton/ha), and T₄(8 ton/ha) Meheguni wood biochar. Each plot contained 6 plants per plot. Growth parameters were measured at 20, 40, and 60 days after transplanting (DAT).

Results: Biochar significantly influenced all four growth parameters (p < 0.05). Plant height increased with higher doses; maximum values were 17.72 cm (T₄) at 20 DAT, 33.97 cm (T₄) at 40 DAT, and 38.75 cm (T₄) at 60 DAT. Leaf number peaked at 10.77 (T₃) at 20 DAT, 12.88 (T₃) at 40 DAT, and 15.56 (T₄) at 60 DAT. Leaf breadth was highest in T₃: 5.8 cm at 20 DAT, 12.53 cm at 40 DAT, and 15.45 cm at 60 DAT. Leaf length reached 14.68 cm (T₃) at 20 DAT and 31.11 cm (T₄) at 40 DAT. No significant effects on development or yield were observed.

Conclusion: Wood biochar at 6-8 ton/ha enhanced vegetative growth of cauliflower, but failed to improve development or yield amid coastal challenges like salinity, waterlogging, and temperature fluctuations. Further studies are needed to optimize biochar for such conditions. These findings demonstrate the potential of biochar to support growth under stress conditions but also indicate the need for optimized application strategies to improve yield.

Insecticidal Activities of Some Tropical Plants Extracts against Malaria Mosquito, Anopheles gambae Giles (Diptera: Culicidae)

Obembe Olusola Michael — 2026-03-28

Anopheles mosquitoes are the primary vectors responsible for transmitting malaria-causing protozoans that affect populations worldwide. The use of synthetic insecticides to control mosquito populations can result in environmental pollution, human health risks, and depletion of the ozone layer. Consequently, there is a growing interest in identifying alternatives to synthetic insecticides. Botanical insecticides, which are inexpensive, readily available, and environmentally friendly, have emerged as viable options. This study investigated the insecticidal effects of methanol, ethanol, n-hexane, and acetone crude leaf extracts from Moringa oleifera, Eucalyptus citriodora, Mentha piperita, Azadirachta indica, and Andrographis paniculata on both adult and larval stages of Anopheles gambiae. Fresh leaves of the selected plants were collected, air-dried, and ground into powders. These powdered leaves were then extracted using absolute ethanol, methanol, n-hexane, and acetone at 60 °C in a Soxhlet extractor. Extract concentrations of 100, 150, 200, 250, and 300 ppm were prepared and tested against An. gambiae larvae and adults, with mortality recorded after 24 hours of exposure. The results demonstrated that ethanol and methanol extracts exhibited strong insecticidal activity, achieving 100% larval mortality at concentrations of 200, 250, and 300 ppm, and 100% adult mortality at 300 ppm. In contrast, n-hexane and acetone extracts showed limited activity against adult An. gambiae. Among the extracts tested, A. indica ethanol extract was the most potent, inducing 100% adult mortality at 300 ppm and complete larval mortality at 200 ppm. These findings indicate that leaf extracts of the tested plants, particularly A. indica, have significant potential for controlling both larval and adult An. gambiae. They may therefore serve as effective, eco-friendly alternatives to synthetic insecticides.

Ecology and Cutting Propagation of Camellia mairei var. lapidea in Vietnam

Trinh Ngoc Bon — 2026-04-20

Camellia mairei var. lapidea belongs to Theaceae family, which has beautiful red flowers used as ornamental plant and seed oil is edible. In this study, C. mairei var. lapidea was first found to have natural distribution in Northwest Vietnam. It grows naturally in an evergreen broadleaved forest on the elevation of 2,100 m above sea level. There were only two adult individuals found, which bloomed and fruited numerously. Ripen fruits were much available on the forest floor, however seedlings or saplings were not available. C. mairei var. lapidea grows on Ferralsols soil with a soil depth of > 1.2 m, low rock content, low soil moisture, and well-drained soil. The maturity individuals may reach to 12 m tall and 18 cm in diameter at breast height. C. mairei var. lapidea flowers during December-February and ripen fruits appear during May-July. After ripening, whole fruits fall with fruit cover and seeds inside. C. mairei var. lapidea exhibits significant potential for vegetative propagation through cuttings, with IBA at 0.5% (w/w) in powder form being the most effective treatment. Even cuttings taken from the natural forest can achieve a rooting ratio of 40% with IBA 0.5%, higher than control of 33.3% at 4 months of growth. With the treatment of IBA 0.5%, cuttings also have the highest shoot number (1.8 shoots), highest root number (6.7 roots), and longest root length (2 cm). It is recommended that further studies should be conducted for C. mairei var. lapidea to meet its potential for ornamental use and oil production.

Some Useful Aromatic Plants with Essential Oils Containing Citronellal of Vietnam

Le Huy Hai — 2026-04-23

Citronellal is a valuable aromatic compound widely used in the fragrance industry and in daily life. The aim of this research is to investigate sources of essential oils with high citronellal content in Vietnam to serve the domestic fragrance industry. The main methods for extracting essential oils were steam distillation. Analysis was performed using a Shimadzu GC-9A gas chromatograph from Japan with a PEG 20M column. The research results identified 18 sources of citronellal-containing essential oils in Vietnam. Essential oils with high citronellal content include Corymbia citriodora (Eucalyptus citriodora Hook), containing 60-75% Citronellal, Cymbopogon nardus, containing 10-20% Citronellal, Cymbopogon winterianus Jowitt, containing 30-45% Citronellal, Cymbopogon tortilis (Presl) A. Camus, containing 10-30% Citronellal, Elsholtzia winitiana Craib, containing 20-30% Citronellal, and Leaf oil of Citrus hystrix, containing 60-70% Citronellal. With its high citronellal content in essential oils and its ability to grow easily in various terrains, Corymbia citriodora will be a significant source of citronellal for both domestic and export needs. The study shows that the sources of citronellal-containing essential oils in Vietnam are abundant and diverse.

Comparative Overview of Community Structure and Functioning of The Flower-Visiting Insects on Physalis minima L. (1753) (Solanales: Solanaceae) and Sesamum indicum L. (1753) (Scrophulariales: Pedaliaceae) in Macha (Bambui, North-West, Cameroon)

Nadine Esther Atibita Otiobo — 2026-04-25

Background: Floral visitors play a crucial role in maintaining agro-ecosystem productivity, yet their dynamics in the highlands of North-West Cameroon remain poorly understood. The plant plays a crucial ecological role by offering alternative nectar and pollen resources, thereby contributing to the maintenance of local pollinator populations.

Aim: This study investigated the entomofauna visiting Physalis minima L. (1753) (Solanales : Solanaceae) (a spontaneous herb) and Sesamum indicum L. (1753) (Scrophulariales: Pedaliaceae) (a major oilseed crop) in Macha (Bambui) to evaluate their diversity, community structure, and interspecific interactions.

Place and Duration of Study: Insect collections and observations were conducted during the 2013 and 2014 cultivation campaigns in Macha (Bambui, North-West, Cameroon).

Methodology: Community structure was analyzed using diversity indices (Margalef, Berger-Parker, Shannon), rarefaction curves, and rank-frequency mathematical models (Zipf and Zipf-Mandelbrot). Interspecific correlations were tested to assess behavioral dynamics.

Results: A total of 42 insect species were identified, with Hymenoptera (Apidae: 41.2%) being the dominant order. Amegilla sp. and Apis mellifera adansonii were the primary visitors, exhibiting clear niche partitioning: Amegilla sp. significantly preferred the tubular flowers of Se. indicum (44.9%), while A. m. adansonii favored Ph. minima (20.7%). Species abundance distributions (SADs) predominantly fitted the Zipf-Mandelbrot model, reflecting a "pioneer-like" system with high dominance and shared competition among leaders. Despite low overall species richness, communities were structured around a stable core of frequent visitors. Interestingly, all significant interspecific correlations were positive, suggesting behavioral tolerance and a synergistic network of floral exploitation. Physalis minima acted as a vital biodiversity reservoir, supporting 80.2% of useful pollinators and a refuge for biological control agents like Paragus borbonicus.

Conclusion : The findings highlight the importance of maintaining heterogeneous floral resources (crops and wild weeds) to preserve a resilient pool of pollinators. Landscape-level management that integrates spontaneous flora is essential for the sustainability of subsistence agriculture and the stability of ecosystem services in the Cameroonian highlands.