不同文心兰品种耐热性指标筛选与评价体系构建OA北大核心CSTPCD

This study was conducted to compare the difference of heat tolerance of different Oncidium cultivars,and to establish a system for evaluating identification indexes of Oncidium heat tolerance.Seven indexes,including the leaf thickness,leaf water content and high temperature semi-lethal temperature(HLT50),of 38 common O.hybridum culti-vars were measured,and the yellow leaf rate and heat injury grade(HIG)of different cultivars were observed under high temperature stress.The evaluation indexes of heat tolerance of Oncidium were screened by analyzing the correlation among different indexes and combining with principal component analysis,to establish the evaluation system of heat resistance of Oncidium cultivars.The results showed that the leaf thickness,leaf water content,HLT50,yellow leaf rate and HIG could well reflect the response of Oncidium to high temperature stress,which could be taken as the index for evaluating Oncidium heat tolerance.The 38 cultivars could be classified into three categories:heat-tolerant cultivars(12 cultivars),moderate heat-tolerant cultivars(3 cultivars)and non-heat-tolerant cultivars(23 cultivars)by cluster analysis based on heat-tolerant index.The results of this study could provide a reference for material selection of Oncidium in hot area,and also provide parental resource for the breeding of Oncidium with high heat tolerance.