Study On Molecular Marker-assisted Screening Of Grape Powdery Mildew Resistant Embryo Rescue Seedlings

Powdery mildew [Uncinula necator(Schw.)Burr.] is one of the most serious fungal diseases in grape production,which seriously affects the development of grape industry.At present,the identification of grape powdery mildew resistance in the field has long cycle and high limitation for cross breeding.Early screening combined with molecular marker assisted selection technology can improve the efficiency of disease resistance breeding.In this experiment,8 cultivated grape varieties(Zaoheibao,Qiuhong Bao,Wanheibao,Jinghongbao,Wuhe Cuibao,Lihongbao,Summer Black,Crimson Seedless)and 2 wild grape varieties(Hejin-1 and Beibinghong)were selected as study materials.Artificial in vivo infection of powdery mildew in grape leaves by needle injection.Then,by setting different temperature gradient(4,20,24,28,32,36 ℃),the agar glass slide method was used to germinate and culture the spores of powdery mildew fungus and the germination and infection dynamics were observed.Field natural identification and seedling stage molecular markers were combined to classify and compare the resistance among of 10 grape hybrid parent material.Further,early detection of powdery mildew resistance molecular markers in hybrid seedlings obtained from the above-mentioned parents was carried out,which provided new materials with reference value for disease-resistant grape breeding.The main results as follows:1.The optimum temperature of grape powdery mildew spore germination was 32℃.2.Among the parent materials of grape hybrids,Beibinghong and Hejin-1 were highly resistant varieties(HR).Qiuhongbao and Wanheibao were part of the high sensitive varieties(HS).The others were medium resistant varieties(MR).3.As for grape powdery mildew resistant SCAR markers SCO11-914,it was applicable for the detection of powdery mildew resistance in hybrid progenies of Summer Black,Crimson Seedless,Zaoheibao,Wuhe Cuibao,Lihongbao,Jinghongbao,Beibinghong and Hejin-1.The grape powdery mildew resistant RAPD markers OPW02-1756 was applicable for the detection of powdery mildew resistance in hybrid progenies of Qiuhongbao,Wanheibao and Hejin-1.4.The molecular marker SCO11-914 for resistance to powdery mildew was used for 20embryo-rescue hybrid progeny lines from 4 crosses.The result showed that the specific band 914 bp of were amplified from 2 progeny lines.The powdery mildew resistance genes of 9 embryo-rescue hybrid progeny lines of cross Zaoheibao×Hejin-1 were detected with OPW02-1756 marker,and 5 embryo-rescue progeny lines were detected.