小麦苗期根系抗低温能力研究

以黄淮麦区种植的10个主要小麦品种为材料,在0～-10℃低温处理下,对其苗期根系的抗低温能力进行了分析,并与当年大田条件下的自然冻害进行比较。2a试验结果表明:0℃处理时,各品种根系抗低温能力没有差异;2007-2008年-5℃处理时,品种间叶片死亡率最大相差25.2个百分点;2008-2009年-2℃、-4℃、-6℃低温处理时,各品种根系抗低温能力差异较大,低温冻害率最大相差分别为8.1、12.5、28.7个百分点;其中,百农矮抗58、邯郸6172和百农160的根系抗低温能力较强。-8～-10℃处理时,各品种均发生比较严重的冻害,最高叶片死亡率达100%。自然条件(-8℃、-11℃)下各品种地上部分(叶片)的死亡率仅为0.4%～9.2%,只相当于-2℃处理时根系产生的冻害。可见,小麦根系对低温更加敏感,远没有地上部分(叶片)抗低温能力强,因此,小麦根系的抗低温能力研究尤显重要。

Study on Cold Resistance of Wheat Root at Seedling Stage

In this study,cold resistant characters of seedling root system of 10 wheat varieties po-pularly cultivated in Huanghuai wheat area were analyzed under low temperature from 0 ℃ to-10 ℃,which was also compared with the naturally cold injury in field.The results in two years indicated that the cold resistant abilities of different cultivars showed no difference under 0 ℃,but they were obviously different under-5 ℃ in 2007-2008 and-2 ℃,-4 ℃ and-6 ℃ in 2008-2009.Among the 10 varieties,Bainong Aikang 58,Handan 6172 and Bainong 160 showed stronger cold resistance than the others.But cold injury seriously occurred in all the cultivars under low temperature from-8 ℃ to-10 ℃,with the highest leaf mortality rate of 100%.Under the natural conditions(-8 ℃ and-10 ℃),the mortality rate of aerial parts(leaves) was only 0.4%-9.2%,just equivalent to the cold injury of roots under-2 ℃.Wheat roots were more susceptible to low temperature than leaves,suggesting that the cold resistance of wheat roots was weaker than that of leaves,so it was of especial importance to study on the cold resistance of wheat roots.