渍水对小麦扬麦5号旗叶和根系衰老的影响

1　引　　言生育中后期渍水是长江中下游麦区小麦高产稳产的主要限制因子13 ,16] .该区由于普遍实行稻麦多熟种植制度 ,前茬水稻使土壤浸水时间过长 ,土壤粘重 ,排水困难 ,透气性差而造成湿害 ;另外 ,该区常年麦季降雨量 5 0 0～ 80 0ｍｍ (浙江省可达 10 0 0ｍｍ)多集中于小麦生长的中后期 ,大大超过了小麦正常需水量 (35 0～ 4 5 0ｍｍ) ,从而加剧渍害5] .　　研究表明 ,渍水小麦株高、地上部干重、分蘖数、主茎绿叶片数、绿叶面积等都受到影响1,12 ,16] ,叶片光合速率、气孔导度、细胞间隙ＣＯ2 浓度下降8] ,ＲｕＢＰＣＯ活性降低14…

Effect of waterlogging on senescence of flag leaf and root of wheat Yangmai 5

In the pot culture experiment, winter wheat ( Triticum aestivum L.) c.v. Yanmai 5 was selected to study the effect of long term water logging, which was conducted from jointing stage to 20 days after anthesis, on grain weight and membrane lipid peroxidation,and on enzyme activities involving membrane lipid peroxide elimination of wheat leaf and root. The content of MDA (malondialdehyde), the product of membrane lipid peroxidation in flag leaf and root under waterlogging increased significantly, while the activities of SOD (super oxide dismutase) and CAT (catalase), two key enzymes involving in membrane lipid peroxide elimination decreased severely. Thereafter, the wheat flag leaf and root under waterlogging senesced much earlier than those under control. Therefore, the grain filling rate of wheat grown under water logging condition decreased significantly, and subsequently, its grain weight decreased obviously.