Physiological reaction differences of different waterlogging- tolerant genotype rapeseed (Brassica napus L.) to anoxia

Chinese. 试图阐明不同耐湿基因型甘蓝型油菜苗期对缺氧胁迫的生理差异响应。试验采用不同耐湿基因型的甘蓝型油菜材料，对发芽种子和幼苗（3叶期）缺氧处理，测定种子发芽性状和幼苗可溶性糖、脯氨酸、相对电导率、丙二醛（MDA）、过氧化物酶（POD）活性、过氧化氢酶（CAT）活性、超氧化物歧化酶（SOD）活性等生理指标。表明耐湿与不耐湿基因型相比具有显著的差异。缺氧处理后耐湿材料发芽种子具有较高的相对发芽率、相对苗长、根长、苗重和活力指数，而相对电导率较低。3叶期幼苗缺氧处理后，耐湿材料可溶性糖和脯氨酸含量提高幅度显著高于不耐湿材料，MDA和相对电导率则显著较低；耐湿基因型POD活性显著提高，CAT活性显著降低，SOD酶活性有较大幅度提高并显著高于不耐湿材料；不耐湿基因型则相反，POD活性显著降低，CAT活性显著提高，SOD酶活性幅度提高较小。缺氧胁迫下，甘蓝型油菜耐湿基因型能显著增加渗透调节有机物含量，同时启动活性氧清除系统，减少膜脂化程度，提高抵御缺氧胁迫。

English. The present study’s objextive was to elucidate the physiological reaction variants of different waterlogging-tolerant genotypes rapeseed (Brassica napus L.) to anoxia. Using different rapeseed genotypes as materials, the germinated seeds and three leaves stage seedlings were treated with anoxia to investigate germination characteristics, content of soluble sugar and proline, relative electrical conductance, malnodialdehyde (MDA), activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) were detected. After 12 h anoxic stress for germinated seeds, the waterlogging tolerant (WT) genotype showed higher relative root and shoot length, fresh weight, survivor rate and relative vigor index, but lower relative electrical conductance. After 48 h anoxic stress for three leaves stage seedlings, the WT genotype showed significant different physiological reactions similar to the susceptive genotype with the rapid increase of soluble sugar and proline contents, lower relative electrical conductivity and MDA content. The different reaction also occurred in activities of activated oxygen scavenger enzyme, and thePOD and SOD activity of the WT genotype increased rapidly. CAT decreased after anoxic stress, while susceptive genotypes with similar level in SOD increased CAT but decreased POD. The results suggested that WT genotype of rapeseed could increase organic osmoregulation content and activities of active oxygen scavenger enzyme increased the anoxic tolerance to waterlogging.