| Wheat powdery mildew and stripe rust, caused by Blumeria graminis f.sp. tritici(Bgt) and Puccinia striiformis f.sp. tritici(Pst), are two important wheat diseases in worldwide. Planting resistant wheat varieties(lines) is the most effective, economical, and environmentally friendly approach to control wheat powdery mildew and stripe rust, and reducing yield losses in field.1. The sensitivity of 6 isolates of Bgt from Gansu province was tested in growth chamber at institute of plant protection, Gansu academy of agricultural sciences. Light incubator was used at 12 different temperatures which were 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃ and 27℃, respectively. The results showed that the mean ET50 of tested isolates was 23.10℃. The highest and the lowest ET50 of isolates were 27.42℃ and 18.16℃, difference 9.26℃ from highest and lowest. There were a certain difference in sensitivity of pathogen populations to temperature. The mean value of temperature threshold of ET100 isolates tested was 28.59℃. With the increase of temperature incubation period, the disease index and severity decreased significantly.2. The virulent gene frequency of 91 isolates to Bgt from Gansu province were analysized in 2013 at greenhouse at institute of plant protection, Gansu academy of agricultural sciences. The results showed that virulent frequency of V1, V3, V4 a, V5, V6, V7, V8, V19, V23, V5+V6, V4+V2X, V4+V8, V4b+V5 and VEra above 70%, and lost its value in planting and breeding in Gansu province, China. The virulent frequency of V13, V16, V17, V18, V21 and V24 low 20% at present time, maybe used in future in wheat breeding. Compared with different isolates of Bgt which come from Gansu, Shanxi and Shandong province, the results showed that virulent gene frequency were significant difference in Pm13, Pm16, Pm18, Pm XBD, Pm21 and Pm2+Pm6+?. The isolates which come from Gansu province had higher virulent than other province. By means of artificial inoculation Gansu Bgt isolates which had different virulent spectrum at seedling stage, the resistance to 35 wheat varieties from Gansu and other province were evaluated. The results showed that only the wheat variety Mianmai 37 was immune to all isolates, about 85% wheat varieties, and its virulent frequency above 60%. The resistant wheat cultivars absent in Gansu province, China.3. A new winter wheat variety Tian 00127, which come from Tianshui institute of agricultural sciences, was used as male parent, and hybridized with the susceptible cultivar Huixianhong, as female parent at Gangu testing station, institute of plant protection, Gansu academy of agricultural sciences(IPP, GAAS). To study the inheritance of the resistance of wheat variety Tian 00127 in seedling stage, the F2:3 populations of the crosses were inoculated with isolate of Bgt-linxia powdery mildew. The results showed that the parent Tian00127 was immune, and Huixianhong was high susceptible. The F1 plants were susceptible, and the F2:3 populations, the resistant plants were 48, susceptible plants were 40, and separation plants were 128, which accorded with the expected value for 1R:2segration:1S in Chi-square(χ2) testing, for probability of goodness fit. The results indicate that the resistance of wheat variety Tian 00127 was controlled by one recessive gene to Bgt-linxia of powdery mildew.4 The winter wheat variety Lantian 23, was used as female parent and hybridized with the susceptible cultivar Mingxian 169 at Gangu testing station, institute of plant protection, Gansu academy of agricultural sciences(IPP, GAAS). To study the inheritance of resistance of wheat variety Lantian 23 to stripe rust in seedling stage. The P1, P2, F1, F2 and BC1 populations of the crosses were inoculated in Lanzhou greenhouse, IPP, GAAS with three races(isolates) of Puccinia striiformis f.sp tritici including CYR32, CYR33 and G22-9. The results showed that the segregation ratio for the cross of Lantian 23 and Mingxian 169 were 62:22 in F2 plants when tested with CYR32, which accorded with the expected value for 3R:1S in Chi-square(χ2) testing for probability of goodness fit. When tested with CYR33 and G22-9,the segregation ratio for the cross of Lantian 23 and Mingxian 169 were 144:54 and 85:24, which also accorded with the expected value for 3R:1S in Chi-square(χ2) testing for probability of good fitness. When tested with CYR32, CYR33 and G22-9, F1 populations were immune, and BC1 populations accorded with the expected value for 1R:1S. The results indicate that the resistance of wheat variety Lantian 23 was controlled by one dominant genes to CYR32, CYR33 and G22-9. According to analysis pedigree of winter wheat variety Lantian, the dominant resistance gene maybe come from the female parents SXAF4-7. |
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