Analysis of Phenotypic Trait Variation in Germplasm Resources of <i>Lycium ruthenicum</i> Murr.

Exploring the phenotypic trait variation and diversity of <i>Lycium ruthenicum</i> germplasm resources can support selection, breeding, and genetic improvement, enhancing agricultural production. This study collected 213 wild <i>Lycium ruthenicum</i> seedlings from a resource nursery in Alxa League, Inner Mongolia. These seedlings originated from eight sources across four provinces. Using 11 pseudo-qualitative traits and 20 quantitative traits, the phenotypic variation of the germplasm was analyzed. The analysis involved the coefficient of variation, Shannon–Wiener index (<i>H</i>), Simpson’s genetic diversity index (<i>D</i>), principal component analysis, correlation analysis, and Q-type cluster analysis. The results showed that the variation range of 31 phenotypic traits across the 213 <i>Lycium ruthenicum</i> germplasm resources was 17.26% to 105.41%, with an average coefficient of variation of 39.85%. The <i>H</i> and <i>D</i> indexes ranged from 0.18 to 1.58 and 0.20 to 0.75, respectively. For the 11 pseudo-qualitative traits, the <i>H</i> and <i>D</i> ranges were 0.18 to 1.58 and 0.07 to 0.74, with average values of 0.77 and 0.42. For the quantitative traits, the <i>H</i> and <i>D</i> ranges were 0.54 to 1.49 and 0.25 to 0.75, with average values of 1.21 and 0.63. This indicates that <i>Lycium ruthenicum</i> germplasm resources exhibit significant phenotypic diversity, with quantitative traits showing higher diversity than pseudo-qualitative traits. Principal component analysis revealed that the cumulative variance contribution rate of the first 10 principal components was 74.03%, comprehensively reflecting the information of the 31 traits. Q-type cluster analysis grouped the 213 <i>Lycium ruthenicum</i> germplasm resources into six clusters, each with distinct phenotypic characteristics. This analysis also identified the trait characteristics and breeding value of each cluster. The results of this study provide valuable information on the genetic improvement, conservation, and evaluation of <i>Lycium ruthenicum</i> germplasm resources.