INVESTIGATIONS ON THE ANTHER CULTURE IN VITRO OF NICOTIANA TABACUM L.AND CAPSICUM ANNUUM L.

The present article deals with an investigation on the anther culture in vitro of tobacco and red pepper. The tobacco anthers were cultured in vitro on 4 different media.Best result was obtained with Nitsch H medium;Blaydes was ledd effective.The percentage of the embryoids formation increases with the addition of 10—20%(v/v)cocoanut milk.The embryoids may be induced with sucrose from 1—4%;and 3% is the optimum. The anthers of different developmental stages were cultured in vitro for com- parison.It is found that when the anther with its pollen grains at the 1-nucleate stage,while the nucleus is situated on one side of the pollen,is the best material for haploid seedling induction. The embryoids were mainly formed in two ways:They were formed either from the development of equal division of the 1-nucleate pollen grain or from the vegetative nucleus of the unequal division of the 1-nucleate pollen grain.The generative nucleus may divide only once or several times but eventually the nucleus and its derivatives degenerate. The chromosome number of the root tip or shoot apex of the pollen plants is found to be n=24;the haploid nature of this plant was confirmed.Colchicine of different concentrations was used to double up the chromosomes of the haploid plantlets.In this way many diploids were obtained and among them a few were tetraploids.The production of the embryoids by different means was discussed. The red pepper anthers were cultured in vitro on NT and MS media,supplemented with different growth substances at the stage when its only nucleus is situated on one side of the pollen grain.The anthers gave rise to embryoids and calli.The develop- ment of the 1-nucleate pollen grain through“proembryo”to the formation of the seed- ling was observed.The development of the embryoids is similar to that of the zygotic embryo. The development of the embryoids from the pollen grains may cease to grow at any stage,hence a few of them may develop into seedlings. The connection between the multicellular“proembryo”and the pollen grain can be seen.The cells inside the pollen grain are large and stained lightly,while the cells of the embryoids outside the pollen grain are small,meristematic and closely arranged; some of them being in the initial stage of differentiation. The cells of the root tip and the callus have been examined with aceto-carmine squash method.The chromosome number was found to be n=12;therefore these plants and calli are haploids.