Double haploid breeding: theoretical basis and practical applications
1989
Snape, J.W. (AFRC Inst. of Plant Science Research, Trumpington, Cambridge (UK). Cambridge Lab.)
Double haploid systems are now available in a number of crop species. These systems have the unique genetic property of allowing completely homozygous lines to be developed from heterozygous parents in a single generation. In self-pollinating species, this property can be saved in getting selected material ready for commercialization. Second, there is an increase in selection efficiency relative to conventional practices because of an increase in additive genetic variation, an absence of dominance variation and within family segregation, and a decrease in environmental variation effects through greater replication possibilities. With outcrossing species, double haploids can increase selection efficiency in recurrent selection schemes although inserting generation of haploidization can slow down the cycle time. Nevertheless, overall breeding efficiency should be enhanced. Different schemes that utilize double haploids in breeding programs are presented and their relative merits are discussed in relation to the biology of the crop being considered, particularly its breeding system and the types of cultivar required.
显示更多 [+] 显示较少 [-]