Effects of inbreeding on agronomic and morphological progenies of Bromus inermis

Smooth bromegrass (Bromus inermis) is an open pollinated grass with gametophytic self-incompatibility. This study was conducted to evaluate the effects of mandatory self fertility on morphological and agronomic traits of Bromus inermis. Three populations including self-pollinated، open pollinated and parental genotypes (each consisted of 25 genotypes of Bromus inermis) were evaluated using a split plot experiment based on randomize complete block design. Significant differences were found among the populations for flag leaf width، days to ear emergence، days to pollination، fresh yield، and dry matter yield. For most of the traits، means of self-pollinated population didn’t have significant differences with open pollinated and parental population due to increasing of homozygosity level، desirable allele frequencies، and fixation of additive effects. Positive correlation was found between dry matter yield with spread and fresh forage yield in self pollinated population. Positive correlation was found between dry matter yield with number of stems in the open pollinated population. Factor analysis for the populations indicated that four factors accounted 78% of the total variation. Finally the results indicated that inbreeding depression is low in Bromus inermis. Therefore، it is possible to develop inbred line in the plant species for breeding objectives.