Choudhury, V. K.Nongrum, Careen2023-07-152023-07-152018https://krishikosh.egranth.ac.in/handle/1/5810198275Chilli belongs to the family Solanaceae. It is a self-pollinated plant having diploid no. of chromosome (2n=24). King chilli is found to be a natural hybrid and occupies a taxonomic position between C. chinense and C. frutescens, clustering more closely with C. chinense group. Capsicum chinense Jacq. cv. is one of the hottest chillies. It is characterized by very high capsaicinoid content. They have various uses such as pungent flavor in food, natural plant colour and pharmaceutical ingredient. Lack of natural vegetative propagation in chilli limits the conservation of genetic purity and thus, micropropagation can be a remedy to this. Capsicum sp. has been found to be recalcitrant under in vitro conditions. The regeneration ability depends on the explant type, genotype and plant growth regulators. True-to-type clonal fidelity is however one of the most important prerequisites in the micropropagation of any plantspecies. High concentrations of different plant growth regulators may induce somaclonal variation at different developmental stages, especially in case of callus derived plantlets. The present study was carried out to develop efficient in vitro regeneration procedure using different explant materials and variable composition and combination of plant growth regulators and for assessing genetic fidelity using RAPD and ISSR markers. Out of 20 MS media supplemented with variable concentrations and combinations of plant growth regulators, 12 media were seen to effective. The maximum number of shoots per explants was seen in MS18 (20 μM BAP + 10 μM IAA) with an average of 2.80 shoots per explant with an average response of 61.13%, the length of shoot was seen to be longest on MS20 (20 μM KIN and 10 μM IAA) having an average length of 2.19 cm and percentage response 78.87%. Analysis of variance showed significant difference for explants for no. of shoots per explant and highly significant for shoot length at 0.05, level of significance. For nodes and internodes, the shoots were not formed in MS media supplemented with both cytokinins and auxins. For fidelity assessment, 16 out of 28 selected RAPD primers generated a unique set of amplification products ranging in size between 200 and 2900 bp, total of 119 fragments within 200 bp and 2900 bp. The number of fragments in each primer ranged from 2 to12.10 out of 13 selected ISSR primers generated a unique set of amplification products ranging in size between 250 bp and 2000 bp, total of 58 fragments within 250 and 2000bp. The number of formed fragments in each primer ranged from 2 to 9. Shoot tips, nodes and internodes in vitro regenerated explants showed monomorphism except for leaf explant through indirect regeneration showed polymorphism corresponding to the mother plant. For standardizing a protocol for in vitro regeneration of King chilli, an effective procedure was found after trial with different explants and combinations and concentrations of growth regulators. The regenerated explants show true-to-type maintaining fidelity except for indirect regeneration. These explants can be used for micropropagation as they maintain the fidelity which would be beneficial as King chilli is an elite plant.EnglishThesis