| Wheat (T.aestivum L.) is the second most important crop after rice in China. However, as a result of the too high costs of production and low quality of Wheat, the sowing area dramatically reduced in the last ten years in the middle and lower Yangtze River area and south China. Meanwhile, a mass of farmland was abandoned during non-rice growing season, and the food supplies security became more serious. So it was urgent to develop bumper-yield and high-quality varieties with disease resistance to various plant diseases.The powdery mildew and the scab of wheat distributed very widely and caused serious damage frequently in in the middle and lower Yangtze River area and south China. Fungicide control not only increase production cost largely, but also caused a series of public disasters such as environment pollution, poison, toxicities to natural enemy, destroying ecological equilibrium. The most cost-effective and environmentally friendly method of controlling plant disease was to breed and spread new varieties.Wuzhuamai, a horny endosperm variety with an unknown resistant gene, was found to be immune to powdery mildew. Sumai 3 was a world-known high resistant variety for scab. In the study, powdery mildew and scab resistances of hybrid generation derived from the two varieties were investigated, and the genetic analysis was carried out. In order to find candidate markers simply and quickly for unknown resistant gene to powdery mildew, a disease-resistance-protein motif restricted AFLP (DMR-AFLP) method was designed firstly by replacing the MseI-adaptor primers in AFLP with the disease resistant protein-specific primers designed according to motifs of fingerprint PR00364 of 33 sequences of wheat. The main results are as follows:1. The resistance of Wuzhuamai to powdery mildew was controled by single dominant gene because theχ~2 test showed the segregation rate accorded with 3:1 (P=0.662) in F2 population and 5:1 (P=0.320) in F3 population.2. The kernel number of main spike and powdery mildew resistance of Wuzhuamai were linkage characters, because the t test showed that the kernel number of main spike had significant differences (P=0.01477) between resistant group (not including heterozygote of powdery mildew resistant gene) and susceptible group in F2 population. Acording to the reports on QTL of kernel number of main spike, the powdery mildew resistance of Wuzhuamai may be present on 1D, 6B, or 4th group.3. FHB (fusarium head blight) resistance of the F2 population was evaluated by biological standardization, and showed quantitative frequency distributions with several peaks. This result implied that the traits are controlled by several genes, or major genes plus polygenes, and proved the biological measuring method is effective. No obvious difference of FHB resistance was found in two groups of resistant and susceptible powdery mildew. This suggested no major QTL of FHB resistance was linkage with resistant gene site to powdery mildew in Wzhuamai.4. Two DMR-AFLP bands were found nonrandom distributions in two groups of resistant and susceptible powdery mildew, and they were hereby thought to be linkage with resistant gene to powdery mildew. This result suggested that the DMR-AFLP was effective to find candidate markers for unknown resistant gene.
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