| Fusarium Head Blight (FHB) is one of the most destructive diseases which cause the yield lost and make the inferior quality of seeds. Recently, with change of crop rotation and climate, wheat Scab was extended and aggravated among the areas in China. In order to control the occur of wheat scab and reduce the damage of disease, It is necessary to understand more mechanism of genetics about resistance to wheat scab through various research methods, especially, DNA molecular level of resistant genes.Great success has been made about genetics and breeding research to wheat scab in China. Wheat varieties, Whangshuibai and Sumai 3 derived in China, are one of the best germplasms of resistance to scab in the world. Many varieties and lines, which showed good resistance to scab, are derivate from these two varieties. More research focused on the variety Sumai 3 before, Wangshuibai was less paid attention. QTL detection and analysis have not been reported using double haploid (DH) population from the landrace Wangshuibai.Two DH populations, which derived the crosses of Wangshuibai/Alondra's and Sumai 3/Alondra's, were produced by Cytogenetics Institute of Nanjing Agricultural University(NAU). Population Distribution, categorization, correlation, genetics stabilization were studied about resistance to scab. Mechanisms of resistant genetics to scab were compared with different varieties Wangshuibai and Sumai 3. Under various environment, QTLs for the resistance to scab were detected through SSR molecular markers. Effects of major QTLs, Epistasis QTLs and interaction between QTLs and environment were evaluated for DH population from Wangshuibai. QTLs primary estimation and effect evaluation related with progress of disease development for wheat scab were made.1. Plant heights from Wangshuibai's DH population showed the continuous normal distribution with one peak. Because variety Alondra's from CIMMYT hold 1RS-1BLtranslocation, RAPD marker OPH20 , which located at the IRS , can be used to test the frequency of IRS distribution in DH population. Ratio of amplified bands to no amplified bands is 69:65, which are qualified to expectation rate 1:1. DH population was qualified for normal distribution and was satisfied with the request of molecular marker mapping.2. Mean value of disease spike is 8.75, 6.85 and 4.87 in the year 2001-2003, respectively. There is significant positive relation for the resistance to scab among years. Taking into account of scabbed spikelets, percentage of scabbed spikelets, progress of disease development in different periods as classify factors, DH population from Wangshuibai could be sorted into four clusters with minimum variance method: stable DH lines of resistance to scab, stable DH lines of susceptibility to scab, DH lines of middle resistance to scab and unstable DH lines of resistance to scab. Criterion of classify is consistent with disease scales of resistance to scab used in wheat breeding program and may become the index between scabbed spikelets and disease scales.3. Mean value of disease spikes is 9.15, 6.82 and 5.26 from Suamai 3 in the year 2001-2003, respectively. Resistance to FHB from Wangshuibai' DH population is better than that from Sumai 3's DH population. Classify analysis showed the same result as Wangshuibai's DH population.4. DH population from Wangshuibai was accorded with inheritance model of two major genes plus poly-genes. There are three kinds of interaction modes of independence, additive and accumulation epistasis. 70% of variances could be account for by major genes, 15% of variances attributed by poly-genes. DH population from Sumai 3 showed the similar result.5. Of the 307 pairs of SSR primers screened, 110 pairs of primers showed polymorphism between Wangshuibai and Alondra's and ratio of polymorphism is 35.83% . There are 10 pairs of primers, which revealed polymorphism between resistant pool and susceptible pool consisted of 6 DH lines, respectively. Xgwm533, Xgwm335, Xgwm282, Xgwm611, Xgwm341 displayed close linkage with genes of resistance to scab. X...
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