Anther/microspore and tissue culture techniques and their applications in wheat and Brassica species.

摘要

Wheat program. Fifty one anther-culture derived lines were obtained by using F1 hybrids of a high bread-making quality line of Triticum aestivum and an elite line of Triticum durum. From these anther-culture derived lines, a disomic 1D addition line of durum type wheat may be selected, which can be used for creating a bread-making durum wheat.; Hybrid necrosis is a serious problem in interspecific crosses of wheats, it is due to two complementary genes: Ne1 and Ne2. Among the regenerates from immature embryo cultures of a necrotic hybrid, about 1-2% normally-growing plants (Re mutants) were recovered. Cytological observation revealed that a Re mutant lost one chromosome, which may carry the Ne1 gene, during tissue culture process. The experiments show that tissue culture methods can be used to bypass the wheat hybrid necrosis problem.; Brassica program. Based on cytological observation and culture experiments, a stepwise floating culture method was established and high efficiencies of embryoid induction were achieved in anther cultures of Brassica napus and other Brassica species. The highest embryoid induction efficiency achieved was 800 embryoids per 100 cultured anthers.; In microspore culture experiments, by culturing microspore-derived embryoids in high sucrose concentration (13%) B{dollar}sb5{dollar} medium containing 1 uM ABA in later stages of embryoid development, embryoids grew to morphological and physiological maturity and then germinated (on low concentration of sucrose medium) directly into normal plants in high ratio (70-95%). By treating microspores with 0.05 colchicine immediately after isolation, a high frequency (82%) of chromosome doubling of the entire plant was obtained. High efficiency of embryoid germination and chromosome doubling, along with a well-established embryoid induction technique, constitutes a highly efficient regeneration system in Brassica napus. This system ensures that a large number of homogeneous lines (doubled haploids) are routinely produced in the shortest period possible, and therefore, provides a powerful tool for breeding.