Abstract:
Objective To provide theoretical basis and genetic materials for breeding and utilization of Eucommia ulmoides.
Method Based on 331 E. ulmoides germplasm resources from 18 provinces of China, correlation analysis, cluster analysis and principal component analysis were conducted for evaluating and selecting superior germplasms with 19 fruit traits.
Result The coefficient of variation of fruit traits was 4.64%-25.79% and the average coefficient of variation was 12.65%. Large variations were found in 100-fruit pericarp wrapping seed kernel weight (25.79%), 100-seed kernel weight (22.32%) and seed volume index (19.53%), while the linolenic acid (4.64%), oleic acid (5.78%) and fruit type index (8.04%) kept relatively stable. The diversity index ranged from 1.6572 to 2.0947, with an average of 2.0234. The 100-fruit weight showed a significant positive correlation with fruit volume index and 100-seed kernel weight, E. ulmoides rubber content significantly and positively correlated to 100-fruit pericarp wrapping seed kernel weight and fruit lateral diameter, while significantly and negatively correlated with crude fat content. Cluster analysis divided the germplasm resources into three groups: small (Ⅰ), medium (Ⅱ), and large (Ⅲ), different types of germplasms were preliminarily defined. Based on principal component analysis, the cumulative contribution rate of the first seven principal components were accounted for 85.169%, ten superior germplasms were selected for evaluation of oil, rubber and comprehensive utilization.
Conclusion E. ulmoides germplasm shows high variation. The yield index has the largest variation, represented by 100-fruit pericarp wrapping seed kernel weight and 100-seed kernel weight, which provides possibility for the selection of superior germplasms. The optimal germplasms selected for different purpose provides an excellent germplasm basis for the breeding and comprehensive utilization of E. ulmoides.