In vivo inter specific cross recovery among different cotton (Gossypium Spp.)

Abstract

Inter-specific crosses, viz., Jayadhar (2x) x BCS-23 (4x), A82-1-1 (2x) X BCS-23 (4x), Jayadhar (2x) x G. australe (2x), Jayadhar (2x) x G. gossypoides (2x) and Abadhita (4x) x G. australe (2x) were attempted. Plant growth hormones like Indole acetic acid, Naphthalene acetic acid and Gibberellic acid with three concentrations were applied to crossed buds to prevent shedding, Very low frequency (0.047-0.15 %) of in vivo cross recovery between cultivated diploid and tetraploid and cultivated and wild species, respectively, indicated the presence of post-zygotic incompatibility. Application of PGRs particularly GA3 @ 0.1 % in 2x x 4x crosses prevented abscission of crossed buds at the highest frequency. There was 36.69 % boll retention as against only 2.70 in control. Phenotyping revealed the intermediate nature of hybrids for most of the morphological characters. Presence of multiple nuclei at tetrad stage (pentad and hexad) was observed cytologically due to abnormal segregation of laggards.