Genetic Diversity Analysis And Comprehensive Evaluation Of Phenotypic Traits In Dwarf Tomato Germplasm Resources

Dwarf tomato has both ornamental and edible value,and is deeply loved by consumers.But,there are few varieties on the market,and most varieties are introduced from abroad with expensive price.At present,there are few reports on genetic diversity and comprehensive character evaluation of dwarf tomato germplasm resources,which restrict the breeding and popularization of dwarf tomato.In this study,the genetic diversity of 45 domestic and international dwarf tomato germplasm resources was analyzed and comprehensively evaluated from the perspective of plant morphology,fruit ornamental and edible,which could provide a theoretical basis for the utilization of germplasm resources and breeding.The main results showed as follows:1.The diversity index of 29 traits of 45 dwarf tomatoes was 0.31 ～ 2.43,of which 9 quality traits were 0.31 ～ 1.46,the mature fruit color was the largest and the fruit shape was the smallest.The 20 quantitative characters were 1.40 ～ 2.43,the internode length was the largest and the fruit shape index was the smallest.The coefficient of variation ranged from 8.51% to 32.51%.The single fruit weight was the largest and the fruit shape index was the smallest.2.Cluster analysis showed that 45 dwarf tomato germplasm resources could be divided into three groups in the genetic distance of 10.The group I accounted for64.44% and had high ornamental value with lower height,larger width and kinds of fruit color as orange,yellow and light yellow,but the fruit taste was poor;The groupⅡ only accounted for 8.89% and had smaller plant height and fruit size,red and orange fruit with higher edible value,which could be used as ornamental and edible materials;The group III accounted for 26.67%,and most of these were semi trailing and had larger and red fruits,which could be used as special ornamental materials.3.Correlation analysis showed that there had complex relationships among various traits.12 phenotypic traits were highly significant or significantly correlated with plant width;Fruit transverse diameter was positively correlated with fruit longitudinal diameter and pulp thickness;There was a significant positive correlation among fruit longitudinal diameter,pulp thickness and fruit shape index;Single fruit weight was positively correlated with stalk length,fruit transverse diameter,fruit longitudinal diameter and pulp thickness.4.Principal component analysis showed that the cumulative contribution rate of the eight principal component factors reached 79.464%.The first and seventh principal component factors were leaf,and the second,third,fourth,fifth and sixth principal component factors were fruit size,fruit appearance,fruit appearance and fruit quality,plant and fruit appearance and fruit color,respectively.The eighth principal component was affected by stem and leaf hairiness,leaf cleavage,hardness,fruit stalk length and leaf color.The top 4 germplasm resources ranked by principal component comprehensive evaluation value were J-190123,J-190108,J-190119 and J-190105,respectively.