Identification Of Cold And Disease Resistance Of Hybrids Of Grape Rootstock

Grape is one of the most important economic fruit trees.The main planting area of grape is in the northwest region of China.It is often affected by low temperature and fungal diseases.Low temperature not only inhibits the growth and development of grapevine,but also causes freeze injury even death of the tree.There are many kinds of fungi diseases that infect grapes,especially powdery mildew,downy mildew and anthracnose,which cause serious losses to grape production every year.The study of grape rootstock resistance to low temperature and fungi diseases,breeding cold and disease rootstock resistance by hybrid breeding is one of the most important content in grape breeding.In this study,we used the grape rootstock parents and their 81 progenies from four cross combinations as experimental materials,four physiological indicators including relative conductivity,soluble protein,proline and soluble sugar of annual dormant grapevine branches were measured by artificial low temperature stress treatment.Then,comprehensive evaluation of the cold resistance of rootstock hybrids was carried out by subordinate function method.Besides,the disease resistance(powdery mildew,downy mildew and anthracnose)was identified for 21 grape rootstock varieties or hybrids,the grape rootstock parents and their 390 progenies from eight cross combinations.The results were as follows:The hybrids of four combinations presented cold resistance separation and the resistance level of hybrids between both parents in general,but there existed the ultra-high or ultra-low parent phenomenon.The cold resistance of grapevine presented a quantitatively inherited character of polygene controlled and tended to weak resistance direction.The hybrids HZ 9 and HZ 10 with high cold resistance and other cold resistant hybrids selected will be used for further breeding new stock varieties.The stock varieties or wild Vitis accessions with the resistance to powdery mildew,downy mildew and anthracnose were: 101-14,110 R,3309,Dog Ridge,1103,Meizhen,520 A,520C,V.riparia Beaumont,Freedom,Salt Creek,V.riparia Mcadams,V.rupestris acc.Constantia,5BB,83-4-96(?),S04,V.Riparia(?),V.amurensis acc.Zuoshan 75097 and Heilongjiang Seedling.V.amurensis acc.Taishan-11 presented resistance to anthracnose and powdery mildew.V.yeshanensis acc.Yanshan-1 and V.vinifera cv.Muscat Hamburg only presented resistance to anthracnose.The resistance of grape rootstock hybrids to powdery mildew and downy mildew showed the quantitative character inheritance,which contained the major disease-resistant gene.However,it showed the dominant inheritance characteristic to the anthracnose resistance.The grape rootstock hybrids with powdery mildew,downy mildew and anthracnose resistance selected will be used for further research to breeding new multi-resistant rootstocks.