Objective The research was conducted to screen out new and desirable varieties of medium-smallsized Cattleya germplasm that grow well under subtropical environmental conditions and show high ornamental values in Guangdong Province.

Method Fourteen introduced Cattleya germplasm were used as experimental materials and adaptive cultivation management and comparative screening were conducted in Guangzhou. The field growth characteristics of different germplasms, ornamental quality traits and resistance characteristics were evaluated systematically through continuous years of observation, characters measurement and statistical analysis.

Result The statistical results of various indicators show that the 11 candidate germplasms have good adaptability in Guangdong and are more suitable for cultivation and application in Guangdong area. Among them, the grade I and grade II germplasms screened out have better plant growth performance, stronger resistance, easier flowering capacity and higher ornamental value, which are worth recommending to the market for landscaping germplasms.

Conclusion Through comprehensive evaluation, three hybrid horticultural varieties of grade I germplasm are selected from 14 candidate germplasms, namely Cattleya Vigour Leopard King(C-3), ProcatavolaPcv.Golden Peacock(C-12)and BrassolaeliaBl.Suzette Chaney(C-14). And these three selected varieties can be used as preferred varieties for cultivation and application in Guangdong. It is recommended that these dominant varieties should be given priority in cultivation, production and leading demonstration applications. At the same time, for other non-dominant germplasms, they can be used as germplasm resources for material preservation according to breeding needs.