3.1.1. Analysis of qualitative and quantitative traits
A total of 56 variations of the 20 qualitative traits were detected in 112 accessions, and the average variation of each trait was 2.8.I ranged from 0.09 to 1.03, with an average value of 0.650. TheI s of the traits (leaf shape, petiole color, and stem color) were greater than 1. The trait with the highest diversity was stem color (I = 1.030), and 59.82% of the accessions were purple green, followed by purple (25.89 %), green (8.93%), and brownish green (5.36%). The I s of stem thorn and stem rotation were the lowest, except for CY-256 and CY-257. All accessions had no stem thorn, and the stem rotated to the right. Bulbil was observed among 35.96% of the accessions. Only two accessions had a round leaf shape, while most were triangular oval (66.07%). Three colors of leaf were observed, and dark green was the most common (68.75%). The leaf apex shape of the yam was acuminate or acute, and the proportion of acute shape was 59.82%. In 112 accessions, 77% of the yam had smaller auricle distance, 21.43% had greater auricle distance, and 2% had an auricle distance of 0. Green and purple were observed in the leaf margin of all accessions, with frequency distributions of 41.07% and 58.93%. Petiole color varied from purple (15.18%), green (24.11%), greenish purple (1.79%), and purplish red (58.93%). The leaf vein color was mainly yellow green, with frequency distribution of 68.75%, and 95.61% of yam leaf veins was observed to be seven. Only 36.61% of the accessions were observed to have stems and wings. Three tuber shapes were observed in all accessions, but cudgel was the most common state (57.14%), followed by massive (33.04%) and columnar (9.82%). Most yam accessions had a low density of root hairs distributed from top to bottom of the tuber. The scarfskin color of most yams was brown, the endodermis color of the tuber was beige, and the tuber flesh color was white, accounting for 70.54%, 73.21%, and 75.89% of all accessions, respectively (Table 2). As shown in Fig. 1, yams have high diversity of phenotypic traits in leaves, stems, and tubers.
The CV of six quantitative traits ranged from 20.81% to 76.11%, and the CVs of the tuber fresh weight, tuber length, tuber diameter, and leaf length were all more than 30%, with the highest being tuber fresh weight and the lowest being length-to-width ratio. The range of tuber fresh weight changed the most (1643.73 g), followed by tuber length (89.92 cm), tuber diameter (15.75 mm), leaf length (13.39 cm), and leaf width (8.88 cm; Table 3). This finding indicated that the quantitative traits of yam tuber and leaf significantly differed in China, the variation range of tuber-related traits in the underground part was larger than that in the aboveground part, and the genetic diversity was rich.