Analysis of Individual Measurement Traits and Selection of Grouping Traits Based on the DUS Test Guidelines for Water Spinach

To establish the grading range of individual measurement traits for water spinach DUS testing and select candidate grouping traits for water spinach DUS testing, a field experiment was conducted with 24 accessions of water spinach germplasm using 14 individual measurement traits according to the requirements of the water spinach DUS testing guidelines. Data were collected and statistical analysis was conducted on the variation and correlation of the 14 individual measurement traits. The measurement traits were divided into grades and principal component analysis was conducted to select candidate grouping traits. The results showed that there was significant variation in the 14 individual measurement traits within and between accessions of water spinach, with a range of 7.14%-17.08% and 10.22%-67.9% for the inter-accession variation of 12 traits being greater than the intra-accession variation. The minimum significant difference method was used to divide the 14 individual traits into grades, which could serve as a reference for the grading of individual measurement traits in water spinach DUS testing. Principal component analysis revealed three principal components, with contribution rates of 46.43%, 25.83%, and 10.79%, respectively, and the three traits were selected as candidate grouping traits based on this analysis. The study can provide reference for the individual measurement trait grading and classification of water spinach germplasm resources.