高温胁迫对二倍体和四倍体萝卜生长和膜伤害的影响

Effects of heat stress on growth and membrane damage of diploid and tetraploid Raphanus sativus L.

在田间试验条件下,比较了自然高温下二倍体和四倍体萝卜的生长情况、株型和产量,并在光照培养箱中研究了高温胁迫(36℃/26℃(昼/夜),10 d)对膜的伤害。研究结果表明,四倍体萝卜的耐热性强于二倍体,四倍体表现出抗热特征:株型直立,叶片增厚,叶形缺刻少趋近板型叶,叶片深绿色且高产,与二倍体相比差异显著。在控制高温胁迫过程中,四倍体的电解质渗透率、可溶性糖和MDA含量均低于二倍体,但两者变化趋势相似;四倍体的SOD、POD和CAT活性,可溶性蛋白及总叶绿素含量均高于二倍体。因此,田间试验结合人工模拟高温可以很好地鉴定萝卜耐热性。

Growth, shape and yield of diploid and tetraploid radish seedlings were compared under high temperature in field conditions and membrane damage was studied at 36 ℃/26 ℃ （day/night） for 10 days in diurnal growth incubator. The tetraploid radish demonstracted a high heat tolerance, characterized by erection, thicker blade, darker green, shorter cave and higher yield, compared with diploid radish, suggesting a significant difference between them. Under the controlled heat stress, the tetraploid had a lower leakage rate of electrolyte, content of soluble sugar and malondialdehyde （MDA）, though a similar tendency existed in hoth. The activities of SOD, POD and CAT, the contents of soluble protein and total chlorophyll in tetraploid radish were higher than those in diploid radish. Then it is possible to test the heat-tolerance of radish under field conditions together with controlled conditions.