[Frequency and contribution of specific genetic loci transferred from wheat cultivar Mianmai 37 to its derivatives].

The development and utilization of outstanding germplasm in breeding programs can expedite breeding process. The high yielding variety Mianmai 37, grown widely in southwestern China, has been used widely in breeding programs. Comparisons between Mianmai 37 and its derivatives for yield and yield components were conducted. Simple sequence repeat (SSR) markers were used to test the frequency of specific alleles transferred from Mianmai 37 to its derivative culti-var Mianmai 367. The results indicated that the yield of the derivative cultivars was significantly higher than Mianmai 37, due to an increased grain number per spike. Favorable traits from Mianmai 37 such as resistance to stripe rust, were trans-ferred to its derivatives. At molecular level, 78.9% loci in Mianmai 367 were derived from Mianmai 37 with 75.0, 83.6 and 74.2% from A, B and D genomes, respectively. Mianmai 367 shared common loci with its parent Mianmai 37, such as re-gions Xgwm374-Xbarc167-Xbarc128-Xgwm129-Xgwm388-Xbarc101 on chromosome 2B and Xwmc446-Xwmc366- Xwmc533-Xbarc164-Xwmc418 on chromosome 3B, these regions were associated with grain number, 1000-kernel weight and resistance. The preferred transmission of alleles from Mianmai 37 to its derivatives probably can be explained by the strong selection pressures because of its favorable agronomic traits and the disease resistance.