5个小菊新品种耐热性综合评价与鉴定

盛夏高温期田间观察开花状况，结合苗期热害指数及相关的生理指标分析，对最新选育的5个小菊品种进行耐热性综合评价。结果表明，高温条件下耐热小菊品种的花芽分化、花蕾发育与开花状况正常；苗期热害指数小，外部形态变化不明显；叶绿素a、a＋b含量开始下降的时间晚(38℃、21h)、下降速度最小，而电导率上升最慢。经综合评价，A1、A8耐热性最强，A9、Y最差，A27耐热性居中。

General Determining Heat Tolerance for Dendrothema cultivars with Small Flowers

Flowering state heat hurt degree and relative physiological index were measured to determine the heat tolerance of five new cultivars in Dendrthema with small flowers. Results showed that flower bud differentionation developing and flower colour weren，t affected by high temperature in heat tolerant cultivar, which showed late and least fall in chlorophyll a、a＋b content,slowest rise in eletric conductivity with the prolongation heat treatment time. Ai and A8 were the best heat tolerant cultivars,while A9、Y were the worst heat tolrant cultivars,A27 was arranged between them.