萝卜种质芽期耐热性鉴定方法初探

The Method of Heat Tolerance Evaluation at Seed Germination in Radish

以18份特征不同的萝卜种质为试材，在25、30、32、35、38℃5个温度条件下进行发芽试验，以发芽率和相对发芽率、发芽指数和相对发芽指数、活力指数和相对活力指数为指标进行萝卜种质芽期耐热性鉴定，并对适宜的胁迫温度和评价指标进行了筛选。结果表明，35℃可作为筛选萝卜芽期耐热种质的适宜胁迫温度，相对发芽率和相对发芽指数比发芽率和发芽指数更适宜作为耐热性的筛选指标，相对活力指数是适宜耐热性筛选的综合指标。

Optimum evaluation methods of tolerance to heat at seed germination were analyzed by determining the germination percentage, relative germination percentage, germination index and relative germination index, viability index and relative viability index of seeds of 18 radish germplasm resources. The test was carried out under five different temperatures, which were 25 ℃,30℃,32 ℃,35℃ and 38℃. Results showed that the sources of the germplasm were different,so were the degree of their heat-tolerance. Under 35 ℃ ,the ability of heat-tolerance was obviously different among varieties and the indexes of each varieties expressed consistent basically. Without considering the difference of germination character under normal condition, results indicated that 35 ℃ was suitable stress temperature and germination percentage and germination index were suitable targets. Contrarily, relative germination percentage and relative germination index were more suitable indexes. The relative viability index was comprehensive index to evaluate the tolerance to high temperature in radish.