Genetic Analysis of callus initiation in Gossypium tomentosum and Gossypium darwinii

Abstract Wild cotton species can contribute a valuable gene pool for the genetic improvement of cultivated tetraploid cultivars. But the obstacle is the reproductive isolation of different species. Somatic embryogenesis offers a temporary status for genetic manipulation such as somatic hybridization. The present studies aimed at optimizing the conditions for regeneration of wild species of cotton. Callus were successfully induced from hypocotyls of Gossypium tomentosum (C 1 genome) and Gossypium darwinii (D 5 genome) on MSB 5 (MS salts and B 5 vitamins) medium supplemented with 0.01mg/L 2, 4-D (2, 4-dichlorophenoxyacetic acid), 0.01mg/L KT (kinetin), 0.01mg/L IAA (3-indoleacetlc acid) and 0.60mg/L 2, 4-D, 0.25mg/L KT, respectively. Plant growth regulators (PGRs) combinations, adding high inorganic salt stress, and carbohydrate were used to induce embryogenic callus from nonembryogenic callus. Embryogenic cultures were induced from the two cotton species. Based on studying the effect of PGRs, nitrogen sources, molysite, CuSO 4 and pH value on somatic embryogenesis (SE), we obtained somatic embryogenesis in the G. tomentosum on the medium with 0.1 mg/L 2, 4-D, 0.1 mg/L KT while deprivation of KNO 3 . The result gives out new exploration on somatic embryogenesis in cotton to create new germplasm sources.