一个成株抗白粉病小麦-簇毛麦T2DS·2V#6L易位系的选育

Development of a Wheat-Dasypyrum villosum T2DS·2V#6LTranslocation Line with Adult-Plant Resistance to Powdery Mildew

白粉病是威胁全球小麦生产的一种严重病害,从小麦野生近缘种发掘成株抗白粉病基因资源对培育持久抗性品种十分重要。本研究从硬粒小麦-簇毛麦01I139(V#6)双二倍体AABBVV-3与普通小麦NAU0686杂交、回交的后代中鉴定到一个小麦-簇毛麦2V#6(2D)异代换系11-2V-1,利用11-2V-1在染色体2V和2D之间产生重组,将11-2V-1与高感白粉病普通小麦NAU0686杂交,F_(1)自交。利用GISH/FISH和分子标记对F_(2)世代131个单株进行分子细胞学鉴定,获得了小麦-簇毛麦T2DS·2V#6L易位系11-2V-2、2V#6S端体系11-2V-3和2V#6L端体系11-2V-4新种质。白粉病抗性鉴定发现,所有F_(2)单株苗期均高感小麦白粉菌生理小种E09,但成株期含有2V#6和2V#6L染色体臂的所有单株均表现高抗(IT=1~2),而仅含有2V#6S染色体臂或无外源染色体的单株均高感白粉病(IT=7~9),表明簇毛麦01I139的2V#6L染色体臂上携带成株抗白粉病基因,该基因可能与小麦-簇毛麦T2BS·2V#5L易位系携带的Pm62是等位基因。遗传效应分析表明,T2DS·2V#6L易位染色体在小麦背景传递正常,对主要农艺性状没有显著的负向影响,对穗长、每穗粒数和单株粒重还表现出一定程度的正向效应。因此,本研究创制的成株抗白粉病T2DS·2V#6L易位系11-2V-2为小麦抗白粉病育种提供了新抗源,也为后续簇毛麦2VL上优异基因遗传定位和图位克隆奠定了基础。

Powdery mildew is a serious disease that threatens wheat production globally.In order to develop durable resistant types of wheat,it is crucial to investigate the powdery mildew gene resources from wild relatives.Here,we identified a wheat-Dasypyrum villosum 01I1392V#6(2D)disomic substitution line 11-2V-1 from the hybridization and backcrossing of the amphidiploid AABBVV-3 of wheat-Dasypyrum villosum 01I139(V#6)with NAU0686.11-2V-1 was further used to generate recombination between chromosomes 2V and 2D by hybridizing with the highly susceptible wheat NAU0686,then F_(1) self-copulation.Three introgression lines,including T2DS·2V#6L translocation line 11-2V-2,t2V#6S ditelosomic line 11-2V-3,and t2V#6L line 11-2V-4 were developed through the combination of GISH/FISH and 2V-specific marker analysis of the 131 F_(2) individuals of 11-2V-1/NAU0686.The F_(2) plants were subjected to powdery mildew test,and the result indicated that all the plants showed high susceptibility to Bgt isolate E09 at the seedling stage.However,all the adult-plant with chromosome 2V#6 or 2V#6L showed high resistance(IT=1-2)to powdery mildew,whereas all the plants with only 2V#6S or without 2V chromatin were susceptible(IT=7-9).These results indicated that an adult-plant resistance gene was present on chromosome arm 2V#6L of 01I139,which could be allelic to Pm62 carried by T2BS·2V#5L translocation line.The results of genetic analysis indicate normal transmission of T2DS·2V#6L in the wheat background.When compared with the recurrent parent NAU0686 plants,the T2DS·2V#6L translocation lines did not show obvious negative effect on agronomic traits.However,the introgression of the T2DS·2V#6L translocated chromosome had an effect on increasing the spike length,number kernels per spike and grain-weight per plant.Therefore,the T2DS·2V#6L translocation line 11-2V-2 provides a new germplasm in breeding for resistance to powdery mildew,and also establishes the groundwork for future genetic mapping and cloning genes located on the 2VL of Dasypyrum villosum.