Abstract: To efficiently utilize the Eucommia ulmoides male flower resources, the morphological traits and active compounds of 193 E.ulmoides germplasms were testd. The screening of evaluation indices and comprehensive evaluation of E.ulmoides germplasms were carried out by using principal component analysis and cluster analysis. The coefficients of variation of water content and amino acids content were smaller than those of other 15 traits among different germplasms. By principal component analysis, 17 traits reflecting the quality of E.ulmoides male flowers could be represented by 8 principal components(cumulative contribution rates of 85.777%). Eight traits including stamen length, yield of per plant, geniposidic acid, chlorogenic acid, isoquercitrin, total flavonoids, amino acids content and water content were selected to comprehensively evaluate the quality of E.ulmoides male flowers. On the basis of composite score ranking, E.ulmoides numbered 10469x, 11042x, 11034x, 10036x, 10464x, 10559x, 10024x, 10060x and 10497x had better quality. The 193 E.ulmoides germplasms were divided into 4 groups at 7.0 by Q-type cluster analysis, the overall traits of E.ulmoides male flowers in the third group was better than other 3 groups, which was consistent with the results of comprehensive evaluation. Eight active compounds were comparatively high in the second group and the morphological traits were also good in the fourth group. The results could provide a reference for E.ulmoides breeding program and the utilization of male flower resources.

Key words: Eucommia ulmoides, male flowers, quality, principal component analysis, cluster analysis