Cytogenetic and RAPD analysis of cotton cultivars and their F1 progenies

Cytogenetic and molecular study was performed in 10 tetraploid cotton cultivars (Gossypium hirsutum L.) including parental genotypes and their F1 progenies. Cytogenetic study showed 2n = 4x = 56 in parental genotypes which differed significantly in their chiasma frequency and distribution as well as chromosome pairing indicating their genetic differences. Adjacent and alternate quadrivalents were formed in the cultivars studied which in turn bring about new genetic recombination and genetic linkages in the progenies. Out of 30 primers used 22 primers produced reproducible bands. In total 387 bands (loci) were obtained out of which 178 bands were polymorph and only 209 bands were common in cotton cultivars studied. Some of the cultivars showed presence of specific bands while, some bands were present in all except one genotype. Some bands were absent in the parental genotypes but present only in their hybrids, whereas some bands occurred in the parental genotypes but absent in their hybrid, all these indicate genetic diffrences of the cultivars studied which is also supported by clustering of the cultivars based on cytogenetic and RAPD data.