外源ABA和BR在提高油菜幼苗耐渍性中的作用

以甘蓝型油菜中双9号为植物材料,应用外源脱落酸（ABA）和油菜素内酯（BR）处理渍水胁迫的油菜幼苗,研究其在缓解油菜幼苗渍水伤害中的作用。结果显示,短期（0～12d）渍水处理可促进油菜生长,长期（18d）渍水处理则抑制油菜生长;叶面喷施ABA（75.67μmol/L）和BR（0.21μmol/L）可有效缓解长期渍水胁迫对油菜幼苗的伤害作用,干物质积累量较单纯渍水处理增加19.52%和26.22%;外源ABA和BR处理还可延缓叶绿素含量的降低,提高叶片光合能力;提高抗氧化酶（SOD、POD和CAT）活性,降低膜脂过氧化（MDA含量降低）;增加叶片可溶性糖含量。说明外源ABA和BR处理通过促进渍水胁迫下油菜幼苗光合作用,提高抗氧化酶活性,提高渗透调节物质含量来增强植株抗渍能力。

Effects of exogenous ABA and BR on waterlogging resistance of juvenile rapeseed

Pot experiment was conducted to investigate the effects of exogenous application of abscisic acid（ABA） and brassinolide（BR） on waterlogging tolerance of juvenile rapeseed（Brassica napus L.cv Zhongshuang 9）.Results showed that short-term waterlogging（0 to 12d） promoted the growth of juvenile rapeseed,while long-term waterlogging（18d） inhibited the growth.Foliar spraying with ABA（75.67μmol/L） and BR（0.21μmol/L） significantly alleviated the injuries of long-term waterlogging stress,and respectively increased 19.52% and 26.22% of the dry weight compared to that of single waterlogging treatment.Furthermore,ABA and BR treatment alleviated chlorophyll degradation and increased leaf soluble sugar contents,photosynthetic rate,as well as superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activities,but decreased malondialdehyde（MDA） content.The results indicated that foliar spraying with ABA and BR could alleviate the negative influence of waterlogging on rapeseed seedlings.