IN VITRO SHOOT INITIATION OF Artocarpus heterophyllus Lam. (Jack fruit). Moraceae

Artocarpus heterophyllus is recognized as a versatile multipurpose tree species in alltropical countries. Its popularity is mainly due to its value as timber, food, fodder,fuelwood and a vast array of medicinal and other non-wood products.Seed propagation is the cheapest, easiest and most convenient method but hasdisadvantages in that the progeny may differ from the parent plant due to the high level ofcross-pollination. Vegetative propagation is very useful but has a relatively poor successrate. Developing a tissue culture technique for clonal propagation of the species will bevery useful for qualitative improvement of the plant with in vitro mutagenesis and cellhybridization.Four types of explants (mature embryos, apical meristems of young seedlings, apices frommature plants and nodal segments) were used in order to initiate shoots in vitro. Theembryos from seeds soaked in water for 24 hours produced shoots after 8 weeks ofincubation and the success rate was 50% while embryos from dry seeds only producedroots. There was no significant effect of cold storage (refrigeration) on shoot initiationfrom mature embryos.It has been found 88% of young apical meristems produced shoots in Campbell andDurzan medium compared to 60% in Murashige and Skoog medium. Only 1/ 3 ofproduced multiple shoots. Shoot initiation from nodal segments was a rare event. Callushas been produced from mature apices. Removal of the sheathing cover around the apexenhanced the shoot initiation from mature apices