大赖草染色体对小麦农艺性状和抗病、耐热性的效应研究

Effect of Chromosomes of Leymus racemosus on Agronomic Traits, Disease Resistance and Heat Tolerance in Wheat

大赖草(Leymus racemosus,2n=4x=28,Ns Ns Xm Xm)具有大穗、多花、抗旱和抗多种病害等优良特性,是小麦改良的重要亲缘物种。前人已经通过染色体工程育成一批小麦-大赖草异染色体系,但是大赖草染色体对小麦主要农艺性状、抗病性和耐热性的效应分析尚鲜有报道。本研究通过人工接种或自然发病抗性鉴定,以分期播种模拟高温胁迫环境并通过千粒重变化评价耐热性,收获后调查主要农艺性状和再生习性,对10个小麦-大赖草异染色体系和小麦亲本‘中国春’进行了综合鉴定。结果表明,10个异染色体系在苗期对白粉病均表现高感,成株期抗性较‘中国春’有所改善,但未发现高抗白粉病材料;对条锈病抗性均优于‘中国春’。研究还发现,大赖草H染色体有增加穗长、小穗数、提早抽穗期和增加黄矮病抗性的效应,H、A染色体具有增加耐热性的效应,J染色体对粒长、粒宽和粒厚均有正向效应,A、L染色体含有控制芒的基因,F染色体具有再生性和复小穗基因。综合上述研究表明,小麦-大赖草异附加系DALr#A、DALr#F、DALr#H、DALr#J可用于小麦农艺性状、黄矮病、条锈病和耐热性的抗性改良。

Leymus racemosus （2n=4x=28, NsNsXmXm） has large spikes, multiple florets, drought tolerance and resistance for several wheat diseases, which is an important genetic resource for wheat improvement. In previous studies, some wheat -Leymus racemosus alien chromosome lines have been developed, but few reports were found about their effect on major agronomic traits, disease resistance and heat tolerance in wheat. In this study, several diseases resistance, heat tolerance and some agronomic traits and regeneration ability of 10 Chinese Spring- L. racemosus alien chromosome lines were evaluated. The results showed that all the tested lines were highly susceptible to powdery mildew at seedling stage after inoculated with the isolate E09, while all the alien chromosome lines showed a bit improved but not significant resistance at adult stage in comparisonwith Chinese Spring in the greenhouse, indicating no single dominant gene for powdery mildew resistance contained in the current chromosomes of L. racemosus introgressed into wheat. Generally, all the alien chromosome lines showed better yellow rust resistance than Chinese Spring after natural infection in the field. Chromosome H of L. racemosus showed positive effect on spike length, number of spikelets, heading date and resistance for BYDV. Chromosomes A and H showed positive effect on heat tolerance through simulating the high temperature environment by interval sowing. Chromosome J showed positive effect on grain size. Chromosome A and L might contain awn-related genes, while chromosome F might contain regeneration and supernumerary spikelet genes. Therefore, the wheat - L. racemosus disomic addition lines of DALr#A, DALr#F, DALr#H and DALr#J would be helpful for improving some agronomic traits, resistance to BYDV and stripe rust and heat tolerance of wheat.