ISSR markers endorsed genetically stable plants regeneration of neem (Azadirachta indica A. Juss.) through indirect organogenesis using different explants.

BACKGROUND: Various parts of neem (Azadirachta indica) have high demand in several industries. However, the inadequate supply of sources hampers the commercialization of different neem products. In this scenario, the current research was undertaken to produce genetically stable plants through indirect organogenesis. METHODS AND RESULTS: Several explants like shoot tips, internodal segments, and leaves, were cultivated on MS media with different growth regulators. Maximum callus formation was achieved using 1.5 mg/L NAA, 0.5 mg/L 2,4-D and 0.2 mg/L both for Kn and BAP in combination with shoot tip (93.67%). These calli showed an organogenic potentiality on MS medium having coconut water (15%) without growth regulators. This medium along with 0.5 mg/L Kn and 0.1 mg/L both for BAP and NAA yielded the maximum adventitious shoot production with shoot tip-derived callus (95.24%). These calli further produced the most buds per shoot (6.38) and highest average shoot length (5.46 cm) with 0.5 mg/L both for BAP and Kn and 0.1 mg/L NAA in combination after the fifth subculture. The 1/3 strength of MS media was found to be best along with 0.5 mg/L IBA and 0.1 mg/L Kn in combination to generate maximum root response (92.86%), roots per shoot (5.86) and longest average root length (3.84 cm). The mean plant survival after initial hardening was 83.33% which increased to 89.47% after secondary hardening. The lack of variation in ISSR markers among the regenerated trees is evidence of clonal fidelity between hardened plants. CONCLUSIONS: This protocol will accelerate the propagation of neem for utilization of its sources.

A standardized protocol for genetically stable artificial seed production of Ficus religiosa L. using ISSR fingerprinting.

Ficus religiosa LQuery. has several ornamental, medicinal, and economical applications. The in vivo propagation of this species has shown various limitations. Due to this reason, the present study efforts on genetically uniform artificial seed production from in vitro developed shoot tips of this species. The in vivo shoot tips were cultivated on Murashige and Skoog (MS) media containing different growth regulators. The maximum shoot response (93.67%) and the longest shoot length (3.85 cm) were exhibited with 0.5 mg L-1 6-furfuryl-amino purine (Kn), 0.2 mg L-1 benzyladenine (BA) and 0.1 mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D) in combination. A treatment of 3% sodium alginate and 75 mM calcium chloride having a polymerization time of 15 min was exhibited to be superior for artificial seed production of these in vitro grown shoot tips. Artificial seed-derived micro shoots yielded the highest root response (94.44%) and roots per shoot (4.61) with 0.5 mg L-1 indole-3-butyric acid (IBA) and 0.1 mg L-1 BA in combination on ½-strength MS media. In comparison to 4 °C-kept artificial seeds, 24 °C-stored artificial seeds had superior germination potential across all storage times. The soil:organic manure (1:1) generated 90% of plantlet survival after 28 days of primary hardening than other mixtures tested. The secondary hardening displayed 92% of plant survival after 60 days. The banding patterns of ISSR analysis between the mother plant and hardened plants were discovered to be monomorphic. This methodology provides a promising and affordable approach to the large-scale plant production of this significant species.

Sex-related Differences of Excoecaria agallocha L. with a View to Defence and Growth.

Excoecaria agallocha is a dioecious mangrove species, reported to have various medicinal properties. This study compares the gender-related biological activities between the sexes of E. agallocha in accordance with morpho-biochemical parameters which indicate their fitness over various environmental stresses as well as some information about the investment of their resources over defence and growth. For this investigation, mature sun leaves of E. agallocha were collected from each sex from three different ecological regions like Bokkhali, Jharkhali, and Kolkata, West Bengal. The comparative study found that leaf of female plants yielded more compounds than males and also resulted in higher anti-bacterial, reducing power, total antioxidant, and lipid peroxidation activities. Female leaves also showed higher concentrations of biochemical constituents like chlorophyll a, chlorophyll b, total carotenoids, total phenolic compounds and total protein content than male leaves. However, leaf area of all-male leaves in all sites was found to be greater than female leaves. The differences in growth rate and secondary metabolite content-based defences between sexes suggest that females invest resources in defences or resistance (Relative electrolytic leakages and TBARS content), whereas male invests their resources in growth (Leaf area) or tolerance. The present study strongly suggests that the female plant's yields are more beneficial in terms of medicinal properties as compared to the male plant.

Clonal fidelity investigation of micropropagated hardened plants of jackfruit tree (Artocarpus heterophyllus L.) with RAPD markers.

BACKGROUND: Artocarpus heterophyllus is an important tropical agroforestry species that bears multiple applications. However, the population of this species is reduced due to various anthropogenic activities. For this reason, in vitro approach is needed to propagate or conserve this species as in vivo propagation methods face various obstacles. In this respect, the present investigation was undertaken to produce genetically stable jackfruit trees through in vitro technology. In vivo grew shoot tips were harvested on Murashige and Skoog (MS) medium containing several plant growth regulators to achieve this. RESULTS: The 6-benzylaminopurine (BAP) at the concentration of 1.5 mg L-1, indole-3-butyric acid (IBA) at 0.5 mg L-1, and α-naphthaleneacetic acid (NAA) at 0.1 mg L-1 in combination on MS media yielded superior shoot response (94.44%), longest shoot length (4.02 cm), and the maximum number of shoots per explant (4.78). They were further multiplied by repeated subculturing on the same media composition and the third subculture resulted in a maximum number of shoots (5.92) with the largest shoot length (5.85 cm). Among the different media screened for rooting, the » MS media yielded 94.44% rooting response, the longest root length (3.78 cm), and the maximum number of roots per shoot (8.44) with 0.1 mg L-1 NAA, 0.5 mg L-1 IBA and 0.1 mg L-1 BAP in combination. Primary hardening showed 88.89% of plant survival under greenhouse conditions after 4 weeks of incubation having a sterilized mixture of garden soil and vermiculite mixture (1:1, w/w). It increased to 90.60% after the secondary hardening process in a vermiculite-soil mixture (2:1; w/w). No polymorphism was detected on random amplification of polymorphic DNA (RAPD) profiling between the mother plant and hardened plants, indicating high genetic stability among the clones. CONCLUSIONS: This is the first report of the genetic fidelity study of in vitro grown regenerants of A. heterophyllus. This study established a micropropagation protocol for genetically uniform in vitro regeneration of this species to supply plant resources to various industries or conservation of elite germplasm.

Assessment of genetic divergence through cluster analysis of chilli varieties.

Our study on genetic diversity was conducted with six chilli genotypes with inter- and intra-specific cross varieties of the three most popular chilli species (Capsicum annuum L., Capsicum chinense Jacq., and Capsicum frutescens L.). Twelve quantitative characters, viz. plant height (cm), primary branches, secondary branches, number of flowers, number of fruits/plant; dry fruit weight (g), fruit length (cm), fruit diameter (cm), pedicel length (cm), pericarp thickness (mm), seeds/fruit, and seed weight (g), were taken into consideration. The analysis of variance revealed considerable variability among the genotypes for the character studied. Cluster analysis was used for grouping of parental and hybrid chilli genotypes under the study grouped into five clusters. Cluster I had the maximum (12) and clusters IVand V had the minimum number (1) of genotypes. The inter-cluster D2 values ranged between 40.404 and 127.530. The minimum inter-cluster distance was between clusters III and IV (40.404). The maximum inter-cluster distance was observed between clusters II and V (127.53). Diversity pattern and other horticultural performance among the genotypes of new varieties were generated due to the cross between Local Line Mahadev Pramanick and Sukhia bullet and also the cross between Local Line Mahadev Pramanick and Habanero orange (cluster II) as well as single parental variety i.e. Habanero orange. These genotypes were identified as promising varieties with respect to various characters may be taken into consideration as better parents for an efficient hybridization programme of chilli.