Evaluation Of Fruit Quality And Stress Resistance Of Different Apple Varieties And Hybrid Superior Lines

China is a major apple producing country,which can be divided into six main apple producing areas according to the geographical location,ecological environment and production and cultivation patterns,among which the Bohai Bay producing area is the dominant apple producing area,and Yantai in Shandong Province,which belongs to this producing area,is the earliest area for edible apple cultivation in China,and the area is rich in excellent apple germplasm resources.The main problem of China’s apple industry at present is the single variety and unreasonable structure;therefore,the selection and introduction of new excellent apple varieties is one of the main goals of the major production areas.Therefore,in this study,eight hybrid lines and 21 apple varieties introduced and cultivated in the Yantai area were used as test materials to evaluate fruit quality by principal component and cluster analysis,to identify cold resistance by conductivity method and recovery growth method,and to evaluate the preliminary drought resistance of apple hybrid lines and varieties based on leaf anatomical structure;in order to provide a basis for the selection and breeding of new apple varieties,for the selection of good parents for crossbreeding,and for the introduction of good varieties in various production areas.The results of this study are as follows:(1)Hybrid 1061 is a medium to late maturing superior line matured in late September,with a single fruit weight of 215.54 g,a* value of 56.37,and bright skin color;hybrid 1101,hybrid 1102 and hybrid 1103 are late maturing superior lines matured in October,the soluble solids content of these three superior lines are 13.51%,14.43% and 14.44% respectively,with square fruit shape and good color.They have good color and good internal and external quality.(2)The cold resistance of different apple hybrid superior lines in order of strength to weakness were:hybrid superior 1061,hybrid superior 1104,’Tianxing’(CK),hybrid superior 1101,hybrid superior 1102,hybrid superior 1062,hybrid superior 1105,’Pink Lady’(CK),(CK),’Pink Lady’(CK),’Pink Lady’(CK),’Pink Lady’(CK),’Pink Lady’(CK),’Pink Lady’(CK),’Pink Lady’(CK),’Pink Lady’(CK),’Pink Lady’(CK),’Pink Lady’(CK),’Pink Lady’(CK)and ’Pink Lady’(CK).’(CK),hybrid 1061,’Tianxing’(CK),hybrid 1062,hybrid 1101,hybrid 1104,hybrid 1102,and hybrid 1103.(3)The comprehensive fruit quality of hybrid 1061 is excellent,with the strongest cold resistance and good overall performance,which can become a new variety with good development prospects,and can also be re-bred as a hybrid breeding parent;the comprehensive fruit quality and resistance of hybrid 1101 and hybrid 1102 are good,with few shortcomings and can be improved through cultivation management,which are excellent medium to late maturing superior lines,and are expected to be declared as new apple varieties;hybrid 1103 has excellent fruit quality but poor resistance,and can be crossed with apple varieties with strong resistance to breed new varieties.(4)Among the 21 apple varieties,those with stronger cold resistance were ’Yanfu 0’,’Yanfu 2’,’Ganghong’,’Lele Fuji’,’Anglin’ and ’Red Guoguang’;the 21 apple varieties were classified into three categories by cluster analysis,and their drought resistance was Class I > Class II > Class III,except for’Yanfu 6’,all of which were stronger than ’Yanfu 3’(CK).(5)Among the 21 apple varieties,’Ganhong’ has a single fruit weight of 269.17 g,soluble solids content of 14.89%,good internal and external quality,strong cold resistance and excellent overall performance,while ’Xishihong’ has a single fruit weight of 192.88 g,a *value of 56.09,with excellent appearance quality,good skin coloration and poor resistance to adversity;both have their own strengths,and ’Ganhong’ has excellent overall quality and good resistance to adversity,but its merchantability is slightly lower than that of ’Xishihong’,both are excellent medium to late maturing apple varieties that can be developed on a large scale.varieties.Late maturing yellow-green varieties of ’Ruishe’ have hard and brittle flesh,strong budding rate and branching power,high net photosynthetic rate and water utilization rate of leaves,and good development prospects as yellow varieties;late maturing red varieties of ’Yanfu 8’ and ’Yanfu 0’ sweet and sour,excellent quality and strong resistance to adversity,can be introduced to the northern apple production areas such as the main production areas of Xinjiang features a large area of cultivation.