ANDROGENESIS INDUCTION, CALLOGENESIS, REGENERATION AND CYTOGENETIC STUDIES OF TOMATO HAPLOID

Four tomato F1 hybrid cultivars (Roma, Maya, Rio Grande and T-55) were used to develop haploid lines during 2005-08. Anthers were cytogenetically analyzed for anther size and meiotic stage. Anthers of varying sizes and meiotic stages were collected at different flowering stages. These were subjected to various pretreatments like low temperature (4, 7 and 10°C) and high sucrose concentration (5, 7, 10, and 12%) for enhancement in androgenic response. Anthers were cultured on MS basal media containing different concentrations of cytokinins, auxins, vitamins and adjuvant. Plants regenerated from androgenic calli were analyzed for their ploidy level under microscope and 9-15 chromosomes could be visualized per haploid cell.