Working group session:
Germplasm and Genetic Stocks
Presentation type:
oral
Authors:
Chen, Yu ; Wang, Yingying ; Zhang, Tianzhen ; Zhou, Baoliang
Presenter:
Zhou, Baoliang
Correspondent:
Zhou, Baoliang
Abstract:
Gossypium australe is a diploid wild cotton species (2n=26, GG) native to Australia that possesses valuable characteristics unavailable in the cultivated cotton gene pool, such as delayed pigment gland morphogenesis in the seed and resistances to pests and diseases. However, it is very difficult to directly transfer favorable traits into cultivated cotton through conventional gene recombination due to the absence of 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 cultivated cotton, we developed a set of hirsutum-australe monosomic alien chromosome addition lines (MAAL) using a combination of morphological survey, microsatellite marker assisted selection, and molecular cytogenetic analysis. The amphidiploid (2n=78, AADDGG) of G. australe and G. hirsutum was consecutively backcrossed with upland cotton to develop alien addition lines of individual G. australe chromosomes in G. hirsutum. From these backcross progeny, we generated the first complete set of chromosome addition lines in cotton; twelve of 13 lines are monosomic additions, and only chromosome 7Ga is multiple addition. MAALs of 1Ga and 11Ga were the first to be isolated. The chromosome addition lines can be employed as bridges for the transfer 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’’ for fluorochrome-labeled DNA fragments, physical mapping, and selective isolation and mapping of cDNAs for a particular G. australe chromosome.