Identification of effective traits for improving forage yield in three species of Agropyron genus

In order to determine relationship among forage dry matter yield and soeveral associatedagronomic traits in Agropyron genus, 31 populations of three Agropyron species (A. desertorum, A. cristatum and A. elongatum) were evaluated in a randomized complete block design (RCBD) with three replications in research farm of Agricultural Biotechnology Research Institute of Northwest and West region of Iran- Tabriz. Correlation coefficients analysis showed that dry forage yield in A. elongatum, had significant positive correlation with canopy diameter and negative correlation with number of days to pollination. For A. desertorum and A. cristatum dry forage yield had also significant and positive correlation with number of stems and negative correlation with flag leaf width. Using stepwise regression analysis, in A. elongatum, canopy diameter and number of days to pollination and in A. desertorum and A. cristatum, number of stem and panicle length were entered into regression model. Path analysis for dry forage yield as a dependent variable, revealed that in A. elongatum canopy diameter had positive direct effect (0.61) and number of days to pollination had negative direct effect (-0.46) and in A. desertorum and A. cristatum, number of stems had positive direct effect (0.73) and panicle length had negative direct effect (-0.44) on dependent variable. Results showed that canopy diameter and the number of days to pollination in A. elongatum, and the number of stem in the A. desertorum and A. cristatum, had great effect in determining forage dry matter yield and therefore, could be recommended as indices in screening suitable genotypes.