小麦白斑突变体I30的特征特性及遗传分析

类病斑突变体是研究植物程序性死亡和抗病性的理想材料。为了丰富小麦斑点突变体的研究,对叠氮化钠诱变小麦品种陕农33产生的稳定遗传的白斑突变体I30进行了特征特性研究和遗传分析。结果表明,突变体I30从三叶期开始表现白色块斑和长条纹。锥虫蓝染色和DAB染色显示,I30斑点处出现细胞死亡和H_2O_2积累现象。透射电子显微镜观察表明,I30的叶绿体形状发生改变,数目减少,基粒垛叠高度无序,部分甚至降解。农艺性状调查结果表明,I30的株高、单株有效穗数、穗粒数、穗长和结实率与野生型间无显著差异,但千粒重、穗粒重、单株产量、旗叶长度和宽度显著低于野生型。遗传分析表明,I30由1对隐性核基因控制。利用BSA+660K基因芯片技术,将该基因定位于小麦6D染色体上,位于SSR分子标记Xcfd190和6DS-5之间,遗传距离分别为6.4cM和9.1cM。

Characteristics and Genetic Analysis of Wheat Mutant I30 with White Stripe Pattern

Lesion mimic mutant is an ideal material for research on plant programmed cell death and disease resistance. In order to enrich the research on wheat spotted mutants,a stable inherited white stripe mutant I30 was generated from Shaannong 33 by chemical mutagen sodium azide,and its characteristics and genetic analysis were conducted. The mutant I30 showed white spots and long stripes from the 3rd leaf stage to maturity stage. Trypan blue staining and DAB staining showed that I30 appeared cell death and the accumulation of H₂O₂. Observation of the chloroplasts structure of I30 with transmission electron microscopy indicated that the shape of chloroplast changed,and the number was decreased and grana stacks in the stroma were highly disordered,and even partly degraded. It was demonstrated that there was no significant difference between I30 and wild type in plant height,effective spikes per plant,spike grain number,ear length and seed setting rate,but the 1 000-grain weight(TKW),grain weight per spike,grain yield per plant,flag leaf length and width of I30 were significantly lower than those of the wild type. Genetic analysis showed that the mutant trait was controlled by a pair of recessive gene. The gene was located on the short arm of chromosome 6D revealed by BSA with 660K gene chip technology,situating between the SSR markers Xcfd190 and 6DS-5,the genetic distances were 6.4 cM and 9.1 cM,respectively.