Determination of the best indirect selection criteria to improve grain yield and seed weight in oat (Avena sativa L.) genotypes

This research was carried out in 2011-2012 years in Kermanshah province located in west Region of Iran. The experimental design was randomized complete block design with three replications. The aim of research was to determine correlation coefficients of 21 oat genotypes among grain yield (GY) and days to flowering (DF), grain number panicle-1 (GNP-1), 1000 grain weight (1000-GW), grain filling period (GFP), panicle number m-2 (PN m-2). Determined direct and indirect effects of yield components on GY through path analysis were also determined. Based on results of correlation coefficients, GY had non-significant relationship with other traits while 1000-GW showed negative and highly significant correlation with DF and GNP. PN m-2 had positive and significant relation with 1000-GW. Path coefficient analysis indicated that PN m-2 and GNP had positive direct effects on GY while DF had positive and direct effect on GNP. However, when the positive direct and indirect effects were added to the negative direct and indirect effects for traits, the sum of direct and indirect effects of GFP and PN m-2 on GY were positive. Also, the direct effect of panicle number m-2 on 1000-GW was positive. The effects of these traits were higher than those of 1000-GW and GNP-1. In conclusion PN m-2 and GNP could have priorities in breeding programs to improve genetically grain yield via indirect selection especially in early generations. Over all, in order to improve the trait 1000-GW selection for higher amounts of PN m-2 should be done in preliminary testing.