Cytogenetic Analysis of Mehr Cotton Cultivar and Its Crossing Progenies: A Search for Unreduced Pollen Grains

Cotton is cultivated in Iran with diploid and tetraploid forms and hybridization is a means to increase the genetic diversity and obtain new elite cultivars in this crop. The present study considers cytogenetic study of the Mehr (Gossypium hirsutum) cotton cultivar and its crossing progenies. The cultivars showed bivalents, univalents and quadrivalents in metaphase of meiosis I. They differed significantly in mean values of chiasmata formation and chromosome pairing due to genetic difference. Different types of meiotic abnormalities like chromosome stickiness, laggard formation, micronucleus, tripolar and multipolar cell formation, cytomixis and unreduced pollen grain formation occurred in the parental genotypes and their hybrids. Grouping of the cultivars based on cytogenetic features showed the effect of parental genotypes on the meiotic behavior of their crossing progenies.