Cytogenetic study and pollen viability of three populations of Diplotaxis harra (Brassicaceae) in Iran

In this study, we examined the chromosome number, microsporogenesis, pollen fertility and distribution of cytotypes of Diplotaxisharra (Forssk.) Boiss. This is the first cytogenetic report of the taxon. Among three studied populations, two of them which belong to central regions of Iran showed aneuploid (x = 14) meiotic chromosome count while the other population existed at the diploid level (x = 13). It seems that the species with x = 14 are derived through aneuploid increase. The most prominent among these meiotic abnormalities was the chromatin stickiness which involved fragmented chromosome at different stages of meiosis. Consequently, these populations exhibited varying percentages of pollen sterility and pollen grains of smaller sizes. The aim of the present research was to study the male meiosis in detail, find the impact of chromatin stickiness in inducing meiotic aberrations and their consequent effects on pollen fertility and find out the distribution patterns of different cytotypes in Iran.