Partial Characterization of Replicase Gene of Tobacco Streak Ilarvirus in Onion (Allium Cepa.L).

Tobacco streak virus (TSV) is an important emerging virus belongs to the genus Ilarvirus and family Bromovidae. The Onion crop is infected by Tobacco streak ilar virus and it is major problem in different places of Andhra Pradesh in South India and also transmitted by thrips vector. TSV suspecting onion samples were identified by direct antigen coating enzyme linked immunosorbent assay using TSV polyclonal antiserum. The Replicase gene from each isolate was amplified using TSV replicase gene specific primers by using the RT-PCR. The ~530 bp product was amplified, cloned, sequenced and determined its length as 534 nucleotides and codes for 178 amino acids. The partial sequence of TSV-Rep shared identity of 87.6 -99.8% at nucleotide levels and 67.8- 99.4% at amino acid levels respectively with other reported TSV isolates. The phylogenetic tree relationship based on the nucleotide sequence of present study isolate (AP-Onion-Chittoor) from different geographical regions was also analyzed in this study.

Studies on Genetic Variability for Yield, Yield Components and Resistance to Kalahasti Malady in Groundnut (Arachis Hypogaea L.)..

Twenty one crosses of groundnut derived from 7×7 diallel set without reciprocals were evaluated during rabi 2010-11 for variability, heritability and genetic advance. Analysis of variance for thirteen traits revealed highly significant differences among the F2 populations tested. The estimates of GCV and PCV were high for number of secondary branches per plant, kernel yield per Plant (g), total phenols content (mg/g), pod yield per plant (g), number of kernels per plant and harvest index. High heritability coupled with high genetic advance as percent of mean for traits viz., days to 50% flowering, total phenols, number of secondary branches per plant, harvest index, kernel yield per plant and number of kernels per plant indicate that these are predominantly influenced by additive gene action and the possibility of phenotypic selection in early generations. High heritability coupled with moderate genetic advance as percent of mean for number of primary branches per plant and moderate heritability coupled with moderate genetic advance as per cent of mean for 100-kernel weight indicate the role of both additive and non additive gene action with preponderance of additive genetic variance and selection would be effective to some extent.