Comprehensive evaluation for fresh-eating jujube varieties based on principal component analysis

ObjectiveThe indexes such as tree body nutrition growth,yield and fruit quality of the successfully intro-duced jujube cultivars were evaluated comprehensively,which could provide reference for screening suitable fresh jujube cultivars for irrigation regions along Yellow River(Gansu section)and other jujube planting areas.MethodSixteen suc-cessfully introduced grafted fresh jujube cultivars of four years old in irrigation regions along Yellow River(Gansu sec-tion)were used as the research objects.Twenty-one indicators such as distribution space of branches and leaves,yield per plant,fresh weight of fruit,soluble solids,acid content,vitamin C(Vc)content,pest resistance and cracking resistance were determined.Principal component analysis was used to evaluate the vegetative growth status,yield and fruit quality of the tree.ResultExcept for edible rate of fruit,the differences in other indicators among various cultivars were ob-vious.Correlation analysis indicated that,there were extremely significant positive correlation between single fruit weight and single stone weight,between soluble solids content and sugar acid ratio(P<0.01).There were significant positive corre-lations(P<0.05)between fruit moisture content and single plant yield,between jujube fruit brittleness and Vc content. Principal component analysis indicated that,the cumulative contribution rate of top seven principal components with ei-genvalues greater than 1.000 was 86.542%.The comprehensive performance of Qiyuexian,Gansufuzao,Jin'ai 3 and Liu-yuexian were better than Wufoyuanzao(CK),their comprehensive scores were 1.916,1.480,1.048 and 0.622 respectively. The comprehensive performance of Huanghuadongzao,Shuguang and Beijingjidanzao were the worst,their comprehen-sive scores were-1.347,-1.092 and-0.976 respectively.ConclusionQiyuexian,Gansufuzao and Jin'ai 3 perform well in tree body nutrition growth,yield and fruit quality,which can be promoted as key varieties in irrigation regions along Ye-llow River(Gansu section).Liuyuexian and Fengmiguan can also be promoted since they have good taste,early mature and high yield. Huanghuadongzao,Shuguang and Beijingjidanzao are not suitable to be developed in irrigation regions along Yellow River(Gansu section).