Genetic diversity analysis and comprehensive evaluation of 35 oat varieties in high cold and humid areas of Tianzhu County

To select forage oat (Avena sativa) varieties suitable for cultivation in alpine and humid regions, this study was conducted to evaluate differences in production performance and genetic diversity among 35 oat germplasm resources in Tianzhu County using a randomized group design in the field, and to analyze the genetic diversity of 14 phenotypic traits and 10 quantitative traits by cluster analysis and principal component analysis. The aim was to promote the full use of existing oat germplasm resources and to identify oat varieties suitable for cultivation in alpine and humid regions. Our results revealed a high genetic diversity index for the 14 examined traits. Leaves displayed the highest diversity index at 1.87, followed by plant height and stem diameter. The largest coefficient of variation was for the number of effective tillers (25.12%), followed by tiller number and spike length. Principal component analysis transformed 10 phenotypic traits into 4 principal components that could represent 86.35% of the original index. The first principal component reflects the number of layers. The second principal component reflects the number of tillers. The third principal component reflects root length, and the fourth principal component reflects leaf width. Cluster analysis divided 35 germplasm resources into 4 groups. No outstanding characteristics were found in group Ⅰ and group Ⅱ. Group Ⅲ is the target parent for breeding dwarf or tiller, and group Ⅳ is the breeding target for high stalk and long spike.