长穗偃麦草DNA导入引起的冬小麦后代性状变异及其遗传研究

为了解外源DNA导入小麦后引起的性状变异及其遗传规律,应用花粉管通道外源DNA导入技术将长穗偃麦草总DNA导入冬小麦陇鉴127中,调查其后代产生的变异,并进行连续选择和抗病性鉴定。结果表明,从D1、D2代开始各性状均产生明显的变异,D3代基本趋于稳定。对陇鉴127的4个变异系的方差齐性检验显示主要性状有明显的变化:株高、旗叶面积、单穗粒数变异程度较大;穗长、千粒重性状比较稳定,不易发生变异;分蘖数具有不一致性和不稳定性,易受环境影响发生变异。抗病性鉴定表明,变异后代有个别表现对条锈病免疫或高抗,部分材料兼抗白粉病。说明个别变异材料中已引入了供体抗锈基因,外源基因已进入冬小麦中并得到表达。研究还表明外源DNA导入冬小麦后引起变异的种类多、范围广、幅度大,具有多样性和复杂性,但不是完全随机的,而是具有重复性和一定的趋向性。

Variation in Winter Wheat Characters Arising from Incorporation of E. elongata DNA and Their Gentic Analysis

Pollen-tube Pathway was used to transfer the DNA of long ears quack grass (E.elongata) into winter wheat (Longjian 127) to study variations of their unborn characters.Subsequent continuous selection and disease-resistance test indicated that the DNA of long ears quack grass had been successfully introduced into winter wheat and was fully expressed. The conspicuous variations of characters were observed in D_1 and D_2 generation and tended to be stabilized in D_3. The result of test for homogeneity for Longjian 127's four variant strains showed conspicuous variations of characters occurred. The result of variant analyse showed variant extent of plant height, particles per plant and boot leave area was bigger. The characters of 1000-seed weight, ear length was stable relatively, their variations were not easy to occur. The characters of tiller showed inconsistency and instability, its character was effected by circumstance factors easily. The result of disease-resistance test to stripe rust showed some of variant offsprings was immune and strongly resistant to stripe rust, some of variant strains showed resistance to wheat powdery mildew. It may be concluded that some disease-resistant gene were introgressed into the acceptor as the result of introducing exogenous DNA. Variant strains highly resistant to stripe rust and with improved characters were obtained in D_4 generation. The variations of offsprings showed diversity and complexity, The variations was not stochastic entirely but was repetitious and tendentious.