Comprehensive Evaluation And Primary Metabolite Analysis Of Tomato Quality Characters

Tomato is one of the vegetable crops widely cultivated in the world.In recent years,the consumption and planting scale of tomato are gradually increasing,and the variety of tomato is also increasing.As a result,consumers have no certain evaluation criteria for fruit quality.The primary metabolites of different tomato types were analyzed in order to select the tomato varieties with excellent quality and flavor.The main conclusions are as follows:1.The genetic diversity index of 27 agronomic traits of 20 tomato varieties ranged from 0.67 to 1.90,among which,the genetic diversity index of 6 quality traits ranged from 0.67 to 1.40,and the genetic diversity index of stem and leaf trichomia(1.38),fruit tip shape(1.40)and fruit shape(1.25)were higher.Therefore,among the 6 quality traits,The main plant morphology of 20 tested tomatoes was stem and leaf fuzz.Among the 21 quantitative traits,the genetic diversity index ranged from0.82 to 1.90,the largest was the first inflorescence node(1.90),and the smallest was the fruit type index(0.82).The coefficient of variation of 21 quantitative traits ranged from 8.32% to 90.48%,with the largest flavonoid content,indicating relatively unstable heredity.The smallest inflorescence node,indicating relatively stable heredity.2.Correlation analysis,principal component analysis,cluster analysis and comprehensive evaluation were carried out for 27 agronomic characters(6 quality characters and 21 quantitative characters)of 20 tomato varieties.The results showed that there was a significant negative correlation between the nutrient quality and fruit size,and a significant positive correlation between the total antioxidant capacity and antioxidant substance content.Eight principal components were extracted by principal component analysis,and the cumulative variance contribution rate was 90.815%.Combined with the results of cluster analysis,12 indexes which mainly affected the comprehensive quality of tomato fruit were screened from 27 traits: Soluble sugars,soluble solids,total phenols,flavonoids,ascorbic acid,lycopene and total antioxidant capacity,titratable acid,single fruit weight,fruit type index,transverse and longitudinal diameter of fruit;The top 5 tomato varieties of comprehensive quality were all small tomatoes,which were successively "rolled pearl screen Little tomato","Wo Xiaohong 765","Wo Huang769","Huang Beibei" and "Black Pearl Little tomato";"Fruit Tomato No.9" with the best comprehensive quality among medium-fruit tomatoes ranked 6th,and "Beiying Dahong" with the best comprehensive quality among large-fruit tomatoes ranked 8th.It also indicated that the quality of small fruit tomatoes was better than that of medium fruit and large fruit varieties,and the comprehensive quality of small red tomatoes was higher than that of small yellow and purple tomatoes.3.Through the study on the nutritional quality of different tomato types during the development period,the results showed that: There were great differences in the content of quality characters of tomato fruits at different developmental stages,among which the corresponding contents of lycopene,soluble solid,soluble sugar,ascorbic acid,sugar-acid ratio and solid-acid ratio also increased in the ripening stage on the whole,while the content of titratable acid showed a decreasing trend in the ripening process.Different types of tomato have the same material accumulation law in ripening process,but there are differences in the rapid accumulation period and accumulation rate.4.A total of 600 metabolites were detected by metabolome analysis of the primary metabolites of different types of tomato at maturity stage,among which the main metabolites were phenolic acids,accounting for29.70%.The results showed that 80.68% of phenolic acids,92.31% of nucleotides and their derivatives,84.62% of carbohydrates and 75% of vitamins were higher in small fruit tomatoes than in large fruit tomatoes.The contents of 70.97% amino acids and their derivatives,63.64%phenolic acids and 69.57% carbohydrates in the differential metabolites of medium-fruiting tomatoes and large-fruiting tomatoes were higher in the medium-fruiting tomatoes,and in the differential metabolites of small-fruiting tomatoes and medium-fruiting tomatoes,The contents of differential metabolites of 72.09% phenolic acids,85.71% nucleotides and their derivatives,75% carbohydrates and 66.67% vitamins were significantly higher in small fruit tomatoes.Meanwhile,the contents of organic acids and lipids in red tomato varieties were higher than those in yellow tomato varieties.The contents of 67.92% phenolic acids,72.73%carbohydrates and 66.67% vitamins in yellow tomato varieties were significantly higher than those in purple tomato varieties.The differential metabolites of 68.63% phenolic acids,77.78% lipids,66.67%carbohydrates and 75% vitamins in red tomato were significantly higher than those in purple tomato.