Study of Relationship Between Forage Yield and Morphologycal Characteristics of Agropyron desertorum Genotypes

In order to study the relationship between forage yield and Morphologycal Characteristics, 31 genotypes of standard crested wheatgrass (Agropyron desertorum Fish.ex Link) in a Randomized Compeletely Block Design(RCBD) with 3 replications, were evaluated in 2 seperate experiments including dry farming and rainfed conditions,condensely, in plots (dimention of 1×2 m) in Islamic Azad University, Arak Branch. Traits such as date of spike appearance, date of pollination, plant height, spike length, spikelet number per spike, size of flag leaf, length of peduncle, thousand grain weight, stem number per plant, seed weight per spike, seed number per spike, harvest index, seed yield and forage yield were measured. Phenotypic correlation analysis indicated that forage yield has a positive and significant correlation in 1% level, with traits such as plant height (r=0.60), number of stems per plant (r=0.46) and seed yield (r=0.44). Obtained results from stepwise regression analysis for forage yield as a dependent variable, indicated significant effects of stem number per plant, date of spike appearance, harvest index, seed yield and seed weight per spike on forage yield with R2=0.93. According to Path analysis, seed yield and harvest index had the most direct effect and also seed yield had the most indirect effect (through a decrease in harvest index) on forage yield.