北京园林绿化耐热白桦种源筛选

摘要

The high temperature resistance of seven Betula platyphylla provenances were compared by physiobiochemical indexes such as leaf relative water content,chlorophyll content,relative conductivity,photosynthetic rate,malondialdehyde and harmed grade after high temperature stress,in order to cultivate high-temperature-resistant-breed of B.platyphylla and enrich plant species in Beijing landscape architecture.The heat endurance types of B.platyphylla were divided by cluster analysis.The results showed that relative conductivity,photosynthetic rate and Harmed Grade among 7 provenances are significant.Provenances ‘ YK' were showed low relative conductivity and higher photosynthetic rate.The conclusion are 1) relative conductivity,photosynthetic rate and Harmed Grade are Key indexes of heat endurance ability of B.platyphylla,2) provenances ‘ YK' is the most potential heat-resistance provenances for Beijing.%为筛选适应北京地区气候的耐热白桦种源,丰富北京园林绿化植物种类,对收集的7个不同白桦种源进行高温胁迫处理,比较了胁迫后不同种源间的叶片相对水分含量、丙二醛含量、叶绿素含量、细胞膜透性和光合速率等指标的差异,并采用聚类分析的方法划分了几种白桦的耐热型.结果表明不同种源的相对电导率、光合速率和形态受害等级差异显著,种源“园科”在细胞膜透性和光合速率等方面表现出较小的胁迫伤害.结论认为相对电导率、光合速率和形态受害指标是白桦耐热性评价的重要指标,种源“园科”是适合于北京地区的最具栽培潜力的耐热白桦种源.