RAPD and Cytogenetic Study in F₁ and F₂ of Interspecific Cross between Gossypium arboreum×Gossypium anomalum

Abstract

An interspecific hybrid between G. arboreum×G. anomalum was obtained by pollinating previous day bagged flowers of G. arboreum genetic male sterile line MPKV GMS with pollen from wild G. anomalum.The chromosome constitution in all the plants of G. arboreum and G. anomalum were found to be normal while interspecific hybrid showed mean chromosome association 1.081^I+10.479^II+0.000^III+0.990^IV with normal sporads. Interspecific hybrid showed anomalous behavior of univalent and formation of single and double chromatin bridges both during fist and second meiotic division of meiosis. Meiotic chromosome association was observed in nine plants of F₂ generation. The cytological studies showed that F₁ and F₂ generations were having irregular pairing and unequal separation of chromosomes. This led to pollen sterility in these generations. In F₂ plants some good plants identified with higher pollen fertility and more number of bolls per plant. Selections from these plants can help to introgress desired characters from G. anomalum to G. arboreum. Random Amplified Polymorphic DNA (RAPD) analysis was employed to characterize the F₁ interspecific hybrid of G. arboreum MPKV GMS×G. anomalum and its nine segregants. A total fifteen primers of 10 mer were screened of which eight were selected based on polymorphism of amplified fragments, amplification intensity and the presence of informative markers. Maximum 98 amplified fragments were resolved on the gel for parents, F₁ and F₂'s with OPC-19 primers, whereas, minimum 25 fragments were seen with OPD-04 primer. Similarity coefficient based on DNA amplification using amplified RAPD primer was estimated. The values for genetic similarity ranged from 0.14 to 0.77.