Manoj Kumar Yadav

Analysis of genetic diversity in cowpea (Vigna unguiculata L.Walp.) cultivars with random amplified polymorphic DNA markers

The genetic diversity among ten Indian cultivars of cowpea was analyzed using 18 sets of RAPD markers. A total of 181 bands with an average of 15 bands per primer were obtained. Out of 181 bands, 148 showed polymorphism (81.7%). The variation in genetic diversity among these cultivars ranged from 0.1742 to 0.4054. Cluster analysis based on Jaccard’s similarity coefficient using UPGMA with high bootstrap values revealed two distinct clusters I and II comprised of two and seven cultivars, respectively. Cluster II was further differentiated into various subclusters. Cultivar IC-9883 was found to be unique based on its altogether distinct position in the dendrogram and two-dimensional space projections.

Physio-Biochemical Alterations Under Moisture Deficit Stress At Different Growth Stages Of Rice (Oryza Sativa. L)

Moisture deficit stress or drought is one of the persistent challenges for the survival of the rice plants to maintain its proper growth and productivity. Drought can occur at any stage of growth and development of rice. In response to the drought stress, various physiological and biochemical alterations have been employed by plant to cope up its adverse effects. Two contrasting rice varieties, Nagina22 (drought resistant) and IR64 (drought sensitive) were studied at 3 stages i.e. seedling, vegetative and reproductive stage under well watered (control) and moisture deficit stress conditions. This present study focuses at identifying changes in physiological and biochemical parameters between Nagina22 and IR64. The mean values of Relative Water Content (RWC), Membrane Stability Index (MSI), Chlorophyll a, Chlorophyll b, and Total chlorophyll decreases significantly during drought stress at different stages. But Proline showed remarkable increase during drought stress at reproductive stage in Nagina22 as compared to IR64. So we conclude that nagina22 is highly tolerant to drought stress than IR64 at reproductive stage.

In vitro multiple shoot bud induction and regeneration from plumule junction explants of pigeon pea [ Cajanus cajan (L.) Mill sp.] cultivars

The response of eleven Indian cultivars of pigeon pea for in vitro multiple shoot bud induction and regeneration from plumule junction explants under variable concentration of 6-benzyl amino purine (BAP), kinetin and thiadiazuron (TDZ) was assessed in the present study. The cultivar IPA-3088 showed best response with a maximum of 20 buds per explants in Murashige and Skoog (MS) media supplemented with 0.05 mgL -1 TDZ. Among the hormones tested, lower concentration of TDZ gave the best response for these cultivars though higher concentration of BAP was also effective in multiple shoot bud induction and regeneration from plumule junction explants. The elongation of multiple shoot buds was achieved in the same medium and the nature of the regenerants in most of the cases was shoots, though in few cases shoot buds and shoot primoridia were also observed. Rooting of plumule junction derived shootlets was found to be better in the presence of NAA as compared to IAA and IBA for most of the cultivars producing maximum number of primary roots. The best responding cultivar IPA 3088 showed efficient rooting in the presence of 0.2 mgL -1 of NAA. The regenerated plantlets were acclimatized in soil with percentage of acclimatization varying from 40-80% for different cultivars. Keywords: Pigeon pea, cultivars, multiple shoot bud induction, organogenesis, acclimatization, elongation, Cajanus cajan (L) Mill sp. African Journal of Biotechnology , Vol 13(41) 4061-4069