Genetic Analysis of Agronomic Traits in Barley (<i>Hordeum vulgare</i> L.)Landrace Lines under Drained and Waterlogged Conditions

Abstract

Estimates of genetic parameters are useful to predict the breeding values of genotypes that will help to make effective crosses. This study was  undertaken to estimate genetic parameters and determine the breeding values of barely landrace lines waterlogged and drained conditions. Two sets of  experiments each consisting of five landrace lines and 10 F1 crosses generated in diallel mating were established in a greenhouse at the University of the  Free State, South Africa. Analysis of variance showed significant variations among genotypes for most studied traits under drained experiment but non-  significant variation for most traits under waterlogging. As compared to the drained experiment, waterlogging reduced grain yield and number of  productive tillers; and delayed days to heading and maturity. General combining ability (GCA) mean squares were significant for most traits, whereas  mean squares for specific combining ability (SCA) were significant only for few traits. Additive gene action was found to be important for days to heading  and maturity while both additive and non-additive gene effects were important in conditioning spike length under both drained and waterlogged  conditions. Under drained conditions, only additive gene action was important for seeds spike-1 and grain yield spike-1, while both additive and non-  additive gene effects were important in conditioning grain yield. The values of estimates of genetic parameters for yield and yield components (except  spike length) were very low under waterlogged conditions, indicating adverse effect of waterlogging stress on the expression of genetic effects. Among  the parental lines, Feres Gama(37) and 1153(28) showed high positive GCA effects for yield and yield components under drained condition Moge(07),  1182(44) and 1153(82) showed desirable GCA effects for early maturity. These parents could be extensively used in future breeding programs to develop  crosses with higher grain yield and desirable agronomic traits. None of the inbred lines showed desirable GCA effects for grain yield and most other yield  related traits under waterlogged condition, indicating the need for further research with increased number of lines to identify the ones with better  combining ability.