Development of a Complete Set of Alien Chromosome Addition Lines from Gossypium australe F. Mueller into Gossypium hirsutum L

Gossypium australe, a native Australia diploid wild species (2n = 26, GG), possesses valuable characteristics unavailable in the cultivated cotton gene pool, such as delayed pigment gland morphogenesis in seed and resistances to pest insects and diseases, but it is very hard to directly transfer these favorable traits into cultivated cotton through conventional gene recombination due to no pairing and crossover between chromosomes of G. australe and G. hirsutum (2n = 52, AADD). To enhance the transfer of favorable genes from wild species into tetraploid cultivated cotton, we report the isolation and identification of a set of chromosome addition lines hirsutum-australe by the combination of morphological survey, microsatellite marker assisted selection and molecular cytogenetic (genomic in situ hybridization, GISH) analysis. Here the amphiploid (2n = 78, AADDGG) of G. australe and G. hirsutum were consecutively backcrossed with upland cotton to develop alien addition lines of G. australe individual chromosome in G. hirsutum. From the above backcrossing progenies, we generated a first complete set of chromosome addition lines in cotton, eleven of 13 lines are monosomic additions except chromosomes 7Ga and 13Ga multiple additions. These chromosome addition lines can be bridged for transference of desired genes from G. australe into G. hirsutum, as well as for gene assignment, isolation of chromosome-specific probes, flow sorting and microdissection of chromosome, development of chromosome-specific "paints" of fluorchrome-labeled DNA fragments, physical mapping, and selective isolation and mapping of cDNAs of a particular chromosome of G. australe.