Pyramiding Resistance To Powdery Mildew And Fusarium Head Blight (FHB) By Molecular Marker-Assisted Selection (MAS)

Powdery mildew and Fusarium head blight (FHB) are two important diseases in wheat. In recent years, China's southwest region, with irrigation levels and the large number of nitrogen fertilizer, wheat powdery mildew and FHB damage are growing, so the fighting against both diseases is becoming more important. Although chemical control of these two diseases has made certain achievements, but it took a lot of manpower, material and financial resources, but also caused environmental pollution and ecological problems. Therefore, cultivation and promotion of resistant cultivars was recognized as against wheat powdery mildew and FHB the most economical, effective and safe way. By hybrid or genetically modified that was highly resistant to powdery mildew, it also has good resistance to FHB, and the characters were better integrated new materials, new varieties of disease for both prevention and treatment was important.In this study, Sumai 3, a resistant wheat variety to FHB, was crossed with Neimai 9, a wheat commercial cultivar with the resistance to powdery mildew. The SCAR(sequence characterized amplified region)markers of powdery mildew resistance gene Pm21 and four SSR (simple sequence repeats) markers (Xgwm493, Xgwm533, Xgwm389 and Xbarc87) covering the major FHB resistance QTL (Qfhs. ndsu-3BS) in Sumai 3 were used to detect the resistance loci by marker assisted selection (MAS) in the plants of the F2 population, combined with powdery mildew and FHB in the field Identification of disease resistance to wheat powdery mildew and FHB. It is want to obtain some plants out of the population with resistance to wheat powdery mildew(including powdery mildew resistance gene Pm21) and FHB (including FHB resistance gene form Sumai 3).The plants perhaps are excellent new parental materials for wheat breeding.The results showed that resistance in field identification:in the 203 plants of the F2 population, the powdery mildew resistance identification results showed that: 138 plants were resistant to powdery mildew, and they showed high resistance to immunization, and they showed the same resistance to Neimai 9; 65 plants susceptible to powdery mildew, they showed high sense, not found in the anti-sense intermediate between the performance of plant disease resistance. Identification of FHB resistance showed that:average spikelet disease rate of Mianyang 31 was 48.27%, the severity of 3 to 5; average spikelet disease rate of Neimai 9 was 41.27%, the severity of 3 to 5; resistant control Sumai 3, the average spikelet disease rate was 14.75%, the severity of 1 to 2. Hybrid plant in the F2 generation of 203 patients was 0～10% of the spikelets were 40 plant and severity of 1 to 2, accounting for 20% of the preliminary view that Sumai 3 resistance and considerable; spikelet disease rate of 55 plant was 10～25%, severity level 2, accounting for 27%; spikelet disease rate of 51 plant was 25～50%, and severity level 3, accounting for 25%; spikelet disease rate of 28 plant was 50～75%,, severity level 4, accounting for 14%, spikelet disease rate of 29 plant was 75～100%, severity level 5, accounting for 14%. Spikelet disease rate among patients less than 25%(severity of 1～2)of the plant with 95, as resistant strains of the remaining 108 patients greater than 25% of the spike rate as a sense of strain. On the whole there were 41 individual plants with high resistance to powdery mildew and FHB immune and Sumai 3 very preliminary, as screened, double anti-plant, then resistance genes using molecular markers.Marker test results:powdery mildew resistance gene Pm21 in specific SCAR markers that 41 pairs of monoclonal anti-treaty could amplify a 1400bp specific band, while the plant was not susceptible amplified this band; using covering Sumai 3 chromosome 3BS FHB resistance QTL main effects of the four SSR markers were 41 pairs of primary resistance to plant for PCR amplification, the results showed that 12 of them could be amplified plant expansion the Xgwm493(210bp), Xgwm533(140bp), Xgwm389 (130bp) and Xbarc87(100bp) Qfhs. Ndsu-3BS specific target fragment, the remaining plant only four markers were amplified in 1 to 3.After this study, the primary field identification of disease resistance and molecular markers check, successfully screened in the F2 generation to 12 while carrying powdery mildew resistance gene Pm21, then with Sumai 3 on 3BS FHB resistance QTL main effect wheat plants, and within the wheat with a large number of excellent genes Neimai 9, its agronomic traits superior to Sumai 3. Therefore, they can be used as much quality and resistance breeding in the middle of materials on this basis is expected to breed improved varieties.