GENOTYPE, EXPLANT AND POSITION EFFECTS ON ORGANOGENESIS AND SOMATIC EMBRYOGENESIS IN EGGPLANT (SOLANUM-MELONGENA L)

The relative importance of genotype and explant, and their interactions for in vitro plant regeneration via both organogenesis and somatic embryogenesis in Solanum melongena (eggplant) has been studied, Hypocotyl, cotyledon and leaf explants of four commercially grown Indian cultivars, Pusa Purple Long, Long White Cluster, Pusa Kranti, and Pusa Purple Cluster were used in the study. A combination of benzyladenine (11.1 mu M) and indoleacetic acid (2.9 mu M) was found to be optimum for shoot regeneration, Naphthalene acetic acid induced embryogenesis in all the three explants; 32.2 mu M was optimum for hypocotyl explants while 10.7 mu M yielded maximum number of somatic embryos from cotyledon and leaf explants, Genotype, explant and genotype-explant interaction had highly significant effects on both organogenesis and somatic embryogenesis with genotype exerting maximum effect on both these processes, Pusa Purple Long was found to be the most responsive genotype for regeneration of both adventitious shoots and somatic embryos among the cultivars, Among the explants, hypocotyls yielded the maximum number of adventitious shoots followed by cotyledons and leaves, The embryogenic response of leaves and cotyledons was, however, significantly higher than that of hypocotyl explants, Significant differences for morphogenetic potential were also observed within a single explant (hypocotyl). There was a basipetal gradient for organogenesis (i.e, decrease in number of shoots from base to apex) while the terminal hypocotyl segments showed better embryogenic potential than the median segments,