| Bread wheat contains three closely related genomes A, B and D, which shows as a homoeologous relationship. However, without homoeologous chromosome pairing occurs during meiosis in this allohexaploid and pairing is strictly confined to homologous chromosomes, which is mainly controlled by the major genes Ph1 and the Ph2, located on 5BL and 3DS, respectively.Common wheat landrace Kaixianluohanmai(abbrev. KL), originated in Sichuan of China, carry gene phKL with promoting effect on homoeologous pairing between wheat and alien chromosomes. In this research, Aegilops variabilis and rye were used as test lines to evaluate the effect on facilitating homoeologous pairing of phKL by comparison with mutations CSph2a,CSph2b and CSph1b. It was showed that mutation CSph1b has the strongest effect on facilitating homoeologous pairing than others. The effect of PhKL was situated between ph1b and ph2.TKL1, a translocation derived from Ae. varibilis as male to cross with F1 hybridization between CS (wheat landrace Chinese Spring was abbreviated as CS) with ph1b and KL with phKL. In wide crosses with alien species, TKL1 showed similar homoeologous pairing level as that of KL with phKL and much lower pairing level than that of CS with ph1b. Meanwhile, SSR (microsatellite) marker analysis showed that 3DS of wheat is still exist, which carries Ph2 gene. The studies results suggested that translocation TKL1 was probably caused by the induction of phKL gene rather than ph1b or Ph2 deletion, thus suggesting the utilization value of phKL in alien chromosomal segment introgression from alien into wheat chromosome via homoeologous chromosome pairing.In addition to, some SSR products in TKL1 were different from that of its parents, which may be caused by DNA slippage during the course of wheat crossing with Ae. varibilis. A lot of SSR primers can amplify products in Ae. varibilis, which referred that these SSR primers from wheat might be used as molecular markers in Ae. varibilis.
|
PDF Full Text Request