تجزیه و تحلیل همبستگی و تجزیه ضرایب مسیر(علیت)خصوصیات زراعی با عملکرد دانه در ژنوتیپ های دوروم بهاره در شرایط دیم گرمسیری و نیمه گرمسیری

In order to identify the relationships of some morpho-physiological traits such as early vigor, plant l1eight, spike length and yield components with grain yield of spring durum wheat on wann dry land conditions of Gachsaran:this study was conducted in a RCB design with 3 replications during 2004-2005 and 2005-2006 wheat growing season in Gachsaran dry land agricultural research station. During growing period data were recorded from different morpho-physiological traits of 24 durum wheat genotypes. Genotypic and phenotypic coefficients of variation, heritability, and genetic advances were calculated. Furthennore path analysis for detennination the direct and indirect effects of yield components on grain yield Was carried out. The result showed that different traits were different in genotyPic and phenotypic coefficients of variations, heritabilities, and genetic advances. Genotypic cOITelation of grain yield with thousand kernel weight(TKW) was positive and high, with the jlumber of grain per spike(G/8) was negative and high while with spike number per unit area(SM2) was negative and negligible. Path analysis for grain yield indicated positive direct effect for all three components of grain yield on grain yield, while indirect effects of TKW and 8M2 via G/S on grain yield were negative and high and vice versa indirect effect of G/S on grain yield via two other components was negative. So for direct selection for TKW and other components decreasing and nullifying the negative indirect effect of other components should to be considered.