Interspecific Hybrids Involving Genetic Male Sterile Line of Gossypium arboreum and Gossypium stocksii

Abstract

An interspecific hybrid between Gossypium arboreum x G. stocksii was obtained by pollinating previous day bagged
flowers of G. arboreum genetic male sterile line MPKV GMS with pollen from wild G. stocksii. A single boll was
obtained after 768 pollinations, containing 9 seeds out of which only two germinated and proved hybrid. The hybridity
was conferred on the basis of cytomorphological observations made in the hybrid plants in comparison with their
parents. The hybrid was intermediate in growth habit, height, leaf shape, petal colour, while anther colour was different
from both the parents. The hybrid plant produced few flowers after 240 days, which were sterile. The chromosome
behaviour during meiosis in both the parent was normal, however, in FI hybrid the average chromosome association
were found to be unequal.The separation ofchromosome and chromatid during anaphase-I and II respectively, leading
to formation of 3 to 7 microspores pollen mother cell and pollen grains with high size variation and sterility was
observed. Efforts are under way to induced chromosome doubling in this hybrid to restore fertility and exploit this
cross combination for transferring drought resistance from G. stocksii to G. arboreum.