Objective To screen high-quality germplasm resources of Dianchonglou (Paris polyphylla var. yunnanensis), reveal the associations between phenotypic traits and saponin content, and lay a foundation for the exploration of genetic resources and the breeding of improved varieties. Methods Through genetic diversity analysis, correlation analysis, cluster analysis (CA), principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and partial least squares-regression analysis (PLS-R), a comprehensive evaluation was conducted on 25 agronomic traits and 10 quality traits of 41 selected P. polyphylla var. yunnanensis germplasm resources. Results The RSD and genetic diversity index (H′) for agronomic traits ranged from 3.56% to 66.63% and from 1.80 to 2.25, respectively. For quality traits, RSD and H′ ranged from 34.26% to 130.18% and from 1.47 to 2.00, respectively. The variation in agronomic traits was mainly attributed to the length of the purple stem portion, pedicel length, and pedicel ratio, while the variation in quality traits was mainly attributed to the contents of polyphyllin V, polyphyllin H, and gracillin. Correlation analysis showed that the sum of polyphyllin I, II, and VII contents was positively correlated with plant height, stem diameter, leaf shape index, rhizome diameter, and powder color values L^*and E^*_ab. Cluster analysis classified the P. polyphylla var. yunnanensis germplasm into three major groups: Group I represented high-yield germplasm, Group II represented high-quality germplasm, and Group III exhibited overall poor growth, low active component contents, and low yield, indicating a generally poor comprehensive performance. PCA simplified the 35 traits into eight principal components, with a cumulative contribution rate of 85.602%. PLS-DA and PLS-R revealed that stem height, leaf length, rhizome diameter, powder color values L^* and E^*_ab, and the total content of polyphyllin I, II, and VII contributed substantially to the D value, and could serve as important indicators for selecting superior provenances. Conclusion The top three germplasm resources based on comprehensive ranking were SZ-16, SZ-11, and SZ-9, which exhibited high quality and high yield, making them potential candidates for cultivation as elite varieties. The stem height, leaf length, rhizome diameter, and powder color values L^*and E^*_ab among agronomic traits, together with the total content of polyphyllin I, II, and VII among quality traits, are important characteristics for distinguishing superior from inferior P. polyphylla var. yunnanensis germplasm.

Paris polyphylla Smith var. yunnanensis (Franch.) Hand. -Mazz  /  phenotypic genetic diversity  /  correlation analysis  /  partial least squares-discriminant analysis  /  polyphyllins  /  comprehensive evaluation  /  elite germplasm screening