Objective Lancang County in Yunnan Province is suitable for cherry tomato cultivation with a good industrial foundation. The correlation of phenotypic traits and the characteristic rules among 28 introduced cherry tomato varieties in Lancang County, Yunnan Province were determined in order to screen out the varieties with good agronomic characteristics that were suitable for cultivation in Lancang County, Yunnan Province.

Method Eight quality traits and 14 quantitative agronomic traits of 28 cherry tomato varieties were investigated by visual observation method, and genetic diversity, correlation, principal component and cluster analysis were carried out.

Result There were significant differences in the main quality traits of 28 cherry tomatoes, such as ripeness, disease resistance, uniformity and mature fruit cracking resistance. A total of 14 varieties with strong resistance were selected, including YTH-FQ-04, YTH-FQ-06, YTH-FQ-07, YTH-FQ-09, YTH-FQ-11, YTH-FQ-12, YTH-FQ-14, YTH-FQ-15, YTH-FQ-18, YTH-FQ-19, YTH-FQ-20, YTH-FQ-21, YTH-FQ-22, YTH-FQ-23, and YTH-FQ-24. Genetic diversity analysis was conducted on 14 quantitative traits and the results showed that the coefficient of variation of phenotypic traits was as follows: flesh thickness > ventricular number > first inflorescence node > second inflorescence node, soluble solids content > fruit transverse diameter, petiole length, first inflorescence node, third inflorescence node > fruit vertical diameter > plant height > single fruit weight > stem diameter > average number of fruits per inflorescence. The results of correlation analysis showed that the fruit transverse diameter was positively correlated with flesh thickness and single fruit weight of 28 materials. The soluble solids content was significantly negatively correlated with fruit transverse diameter and single fruit weight. The average number of fruits per inflorescence, fruit transverse diameter, petiole length, ventricular number and fruit vertical diameter were correlated as the main evaluation factors of cherry tomatoes, and the cumulative contribution rate was 77.46%. According to cluster analysis, 28 tested cherry tomato varieties were divided into 4 groups at 3.0 Euclidean distance. Group 1 were mainly large-fruit type cherry tomatoes, with the largest single fruit weight, thick peel and few fruits per inflorescence. Group 2 mainly consisted of medium-fruit cherry tomatoes with large single fruit weight. Group 3 were small-fruit cherry tomatoes, which had the smallest single fruit weight and the highest soluble solids content. Group 4 contained 21 materials, with high soluble solids content and high average fruit number per inflorescence.

Conclusion In this experiment, a total of 7 cherry tomato varieties with strong disease resistance, strong crack resistance, high uniformity and good taste were selected, including YTH-FQ-06, YTH-FQ-07, YTH-FQ-09, YTH-FQ-11, YTH-FQ-12, YTH-FQ-18 and YTH-FQ-24. Most phenotypic traits of 28 cherry tomato varieties showed the same rule in correlation analysis and cluster analysis.