Analysis on Individual Measurement Traits of Ipomoea aquatica and Selection of Grouping Traits Based on DUS Test Guidelines

In order to establish the grading range of individual measurement traits for DUS testing of Ipomoea aquatica and screen the candidate grouping characteristics of DUS test guidelines for Ipomoea aquatica, 24 Ipomoea aquatica germplasm resources were used as the materials, and according to the requirements of DUS test guidelines for Ipomoea aquatica, the planting test was carried out and the data were collected. Then, the degree of variation and correlation of 14 individual metrical traits were counted and analyzed. The classification range of the metrical traits was divided and the principal component analysis was performed to screen the grouping characteristics of the DUS test guidelines. The results showed that there was significant variation in the 14 individual metrical traits within and among varieties of Ipomoea aquatica. The coefficient of variation ranged from 7.14% to 17.08% and 10.22% to 67.9%, respectively, and the variation of 12 traits among varieties was greater than that within varieties. The minimum significant difference method was used to divide the grading range of 14 individual traits, which could serve as a reference for the grading of individual metrical traits in Ipomoea aquatica DUS testing. Three main factors were obtained by principal component analysis, and the contribution rates were 46.43%, 25.83% and 10.79%, respectively. Based on this, three candidate grouping traits were screened out. This study could provide reference for the grading of DUS individual metrical traits and the classification study of Ipomoea aquatica germplasm resources.