5021
AYMAN ANTER SABER ABDALLAH
EVALUATION OF SESAME LINES IN ADVANCED BREEDING GENERATIONS
Sesame (Sesamum indicum L.), genotypic variance, heritability, correlation, direct selection, expected and actual genetic advance, conventional and restrictedselection indices, rank correlation.
Selection index was constructed to help selection for several important traits simultaneously. Judicious use of conventional and restricted selection indices is of a great importance to the breeder because selection focuses on breeding value, the portion of genetic superiority transmitted to progeny. Selection of F6 line (s) that combine high seed yield with one or more desired agronomic or seed yield component trait in a new cultivar was practiced via 12 conventional and two restricted selection indices. These lines were evaluated in the next generation (F7) in an evaluation experiment. The two experiments were grown in the Agricultural Production and Research Station of National Research Center, El Nubaria district, Egypt, in 2011 and 2012 seasons, respectively. The results showed significant genetic variances among lines for all studied traits expect days to maturity in F6 and fruiting zone length in F7. Mean performance of F6 and F7 lines were higher than the check cultivar for number of branches plant-1, number of capsules plant-1, seed yield plant-1, oil % and seed yield plot-1. Height to 1st capsule, branches plant-1 and seed yield plot-1 showed higher values of PCV and GCV, also reported from high to moderate heritability. There are no discrepancies between expected and actual genetic advances reported for four traits viz., fruiting zone length, number of branches plant-1, number of capsules plant-1 and seed yield plot-1 while other traits showed discrepancies. The lines C1.5 and C3.8 showed 1.14 and 1.16 fold the genetic advance in favor of actual as compared to the expected genetic advance. Seed yield plot-1 showed positive significant correlation with plant height, stem height to 1st capsule, number of branches plant-1, number of capsules plant-1 and seed yield plant-1 in F6 and F7, but it was negative and significant correlated with seed index and oil%. Conventional selection index N0.11 which contains four traits viz., plant height, number of branches plant-1, number of capsule plant-1 and seed yield plot-1 reported the highest genetic advance and relative efficiency of direct selection for seed yield plot-1 itself. Holding seed index and/or oil % of selected sesame plants to the means of unselected plants in a restricted selection indicesincreased the seed yield plot-1 by 8.0 and 4.0% of lines mean while conventional selection index decreased seed yield plot-1 by 32 and 41%. Certain lines appeared in the selected sample of lines regardless of the procedure used and selected percentage (top 10 and/or 20%) ;their names were, C1.5, C1.6, C1.8, C3.8, C6.3 and C6.5. Estimations of rank correlation indicated that direct selection for seed yield plot-1 was nearly as effective as conventional selection indices which included more than two traits. The line C3.8 recorded the highest seed yield plot-1 amongst the 27 elite lines in F6 and F7 as well as check cultivar and reported higher resistance for Charcoal-rot and Fusarium wilt diseases and their combinedinoculation.
2015
Ph.d
Cairo
Agriculture