Effects of Pollination System and Water Deficit on Bromus Inermis

This research was conducted to study the amount of self- incompatibility in 25 genotypes of Bromus inermis, under two water environments (non-stress and drought stress) in a completely randomized block design. For this purpose, half of the panicles of each genotype were bagged for obligate selfing and the others were allowed to open pollination. Results showed that under non-stress condition the average number of seeds per panicle for open pollination was 161.4 and for selfing mode was 5.6, indicating the high rate of self-incompatibility in this grass. Under drought stress condition, these values were 142.8 and 4.7, respectively, showing the effect of relative environmental conditions (drought stress) on seed production in regard to both the selfing and crossing. The same trend was also observed for seed weight. Under non-stress condition, variation among genotypes for seed weight per panicle was more than the stress condition. High variability was observed among genotypes for self-compatibility index, and thus the genotypes with the highest and lowest incompatibility index were determined.