Thermo-sensitive genic male sterile (TGMS) lines have specific superiority in heterosis utilization of crops. So far, thermo-sensitive genic male sterile lines have been found in many plants and are widely used in two-line hybrid breeding. With the rapid development of molecular biology, the molecular nature of thermo-sensitive genic male sterility has been revealed, which lays the foundation for further devel- opment and utilization of thermo-sensitive genic male sterile lines. In this study, the molecular mechanisms of fertility conversion of plant thermo-sensitive genic male sterile lines were reviewed from gene molecular mapping and gene differential ex- pression, and the mechanisms of gene differential expression in thermo-sensitive genic male sterile lines were further discussed.
[Objective] The correlation between genetic distance and heterosis of the major Brassica napus L. cultivars in Yunnan Province was analyzed. [Method] The genetic distances among the 8 major Brassica napus L. cultivars in Yunnan Province were investigated with the SSR molecular marker technique. Moreover, the correlation between genetic distance and field appearance of heterosis was ana-lyzed. [Result] There was a certain correlation between the genetic distance and heterosis of crossing parents (P〉0.05). [Conclusion] It is difficult to predict the het-erosis of Brassica napus L. cultivars and to screen parents by using the SSR molecular marker technique.