彩叶芋2个品种抗寒性的比较

以彩叶芋Caladium bicolor 2个品种的组培苗为试验材料,通过人工低温处理(0～20℃),研究彩叶芋叶片中的相对电导率、可溶性蛋白质量分数、可溶性糖质量分数、游离脯氨酸质量分数、超氧化物歧化酶(SOD)活性的变化,进行方差分析和多重比较分析,计算其半致死温度。2种彩叶芋品种叶片的半致死温度均较高。相对电导率与抗寒性呈负相关,可溶性蛋白、可溶性糖、游离脯氨酸、SOD活性与抗寒性呈正相关。研究分析表明:各个指标在不同温度和不同品种间的差异都达到了极显著水平(P<0.01)。其中相对电导率、可溶性蛋白、可溶性糖量、SOD活性可以更好地反应彩叶芋在低温下的生理变化及不同品种之间的抗寒性差异,可定为彩叶芋品种抗寒鉴定的初步指标。游离脯氨酸与彩叶芋抗寒性的关系还有待进一步研究。彩叶芋抗寒性的强弱为漆斑彩叶芋Caladium bicolor‘Wightii’>红艳彩叶芋‘Postman Joyner’。

Cold-resistance in two Caladium bicolor cultivars

Caladium bicolor ‘Wightii’ and ‘Postman Joyner’ tissue culture plantlet were treated with low temperatures（0-20 ℃） to determine changes in relative electrical conductivity, soluble proteins, soluble sugars, proline, and superoxide dismutase（SOD） activities. Analysis of variance, correlation analysis, and multiple comparisons were utilized; and the semi-lethal temperature was studied. The semi-lethal temperature of the two C. bicolor cultivars was high. Relative conductivity of the two C. bicolor cultivars was negatively correlated to cold resistance ability. However, soluble proteins, soluble sugars, proline, and SOD activities were positively correlated with cold resistance of the two C. bicolor cultivars. Analysis of variance showed that various indicators at different temperatures and different cultivars have reached a very significant level. Thus, in response to physiological changes with low temperature, relative conductivity, soluble protein, soluble sugar, and SOD activities were reliable indicators of cold hardiness and of cold tolerance for these two cultivars, but the relationship between proline and cold resistance must be further studied. Cold resistance of C. bicolor ‘Wightii’was better than that of C. bicolor ‘Postman Joyner’.［Ch，5 fig. 1 tab. 16 ref.］