Ontogeny of Somatic Embryos of Vigna aconitifolia, Vigna mungo and Vigna radiata

Callus cultures were initiated from immature cotyledons of Vignaaconitifolia, V. mungo and V. radiata on MS medium supplementedwith NAA, picloram or 2, 4-D. On transfer to L-6 liquid mediumsupplemented with low concentrations of picloram, GA₃ and cytokinins,large number of somatic embryos differentiated from the callus.The cells destined to become somatic embryos divided to formspherical or filamentous proembryos. From the filamentous proembryo,the embryo proper developed either at single or multiple sites.Development of somatic embryos from multiple sites resultedin several embryos connected by a common suspensor at the radicleend. Continued divisions of the proembryos led to globular,heart shaped and dicotyledonary stages of somatic embryogenesis.The somatic embryos of V. mungo and V. aconitifolia differentiatedinto tiny plantlets at low frequency (1%) in liquid suspensioncultures supplemented with zeatin, picloram and GA₃. Vigna aconitifolia Jacq, Marechal, mothbean, Vigna mungo L. Hepper, urdbean, Vigna radiata L. Wilczk, mungbean, somatic embryo     

In Vitro Induction of Haploid, Diploid, and Triploid Androgenic Embryoids and Plantlets in Datura metal L.

Pollen plantlets of Datura metel L. have been successfully rearedin vitro through anther culture on a nutrient medium supplementedwith coconut milk (15 per cent v/v) The early segmentation patternof the proembryos and their subsequent differentiation intoheart, torpedo, and cotyledonary stages were traced. More than100 plantlets were grown to maturity on soil. They grew normallyand produced flowers. Root-tip and leaf-squash preparationsshowed variable numbers of chromosomes in their cells, and thisindicated the occurrence of ploidy plants among the population.Frequency determinations showed the predominant types to bediploid (70 per cent), triploid (24 per cent), and haploid (6per cent). Differences in the morphology of mature plants inregard to floral size, meiotic irregularities in PMCs, formationof giant pollen grains, differential fruitset, somatic mosaicismin respect of chromosome number, and aneuploidy of cells, wererecorded. The origin of diploid and triploid plants is discussed.