Objective  Genetic variations on major traits of local Chinese yam germplasms in Fujian were evaluated for development and breeding of high-quality varieties.

  Method  The 24 selected traits on 37 yam varieties (Dioscorea polystachya) were studied with the diversity, correlation, principal component, and cluster analyses.

  Result  The variation coefficients on the quantitative phenotypic traits of the germplasms ranged from 21.01% to 68.26%. That of the tuber was greater than those of the aboveground parts of a plant. The descriptive traits had diversity indices ranging between 0.281 and 1.349. Those on the growth potential of aboveground parts as well as those on the shape, skin smoothness, and fibrous root number of tubers were greater than 1. There was a significant correlation between the leaf, petiole growth, and stem girth of the aboveground parts and the tuber development. Therefore, the tuber yield of a plant could be estimated by the aboveground observations. The cumulative contribution by the top 5 principal components that reflected the aboveground growth of shoots and leaves as well as the underground yam yield was 80%, while the first principal component alone contributed 43.76%. The cluster analysis classified the 37 germplasms into 4 groups with the Dioscorea alata being the highest on phenotypic diversity.

  Conclusion  The diversity of the germplasm collection of Chinese yams in the province were abundant. The tubers were more diversified than the stems and leaves among the germplasms. There were correlations among the growth of aboveground plant parts and the traits related to the tuber yield which could be used for production estimation.