小麦-偃麦草杂种后代及小麦种质资源对纹枯病的抗性

Reaction of Wheat-Thinopyrum Progenies and Wheat Germplasm to Sharp Eyespot

为鉴定小麦-偃麦草杂种后代以及我国小麦品种和育种中间品系对纹枯病的抗性,并且解析偃麦草染色体与纹枯病抗性的关系,在徐州和南京两个试点,采用田间病圃法对321份普通小麦品种或品系和56份小麦-偃麦草杂种后代材料进行了纹枯病抗性鉴定。在徐州试点没有发现高抗纹枯病的种质,但是有52份材料表现中抗反应型,包括34份普通小麦材料,其中萧农8506-1、小偃81、冀植4001、农大195、徐州8913和京东3066A-3的相对抗病指数高于0.7。在南京试点,全部普通小麦材料都不抗纹枯病,只有5份小麦-偃麦草种质表现中抗反应型。部分小麦-偃麦草种质的病情指数不但显著低于感病对照品种苏麦3号和扬麦158,而且还低于抗病对照品种安农8455和宁麦9号,如小麦-中间偃麦草4Ai#2或4Ai#2S附加系、代换系和易位系材料TA3513、TA3516、TA3517和TA3519及小麦-长穗偃麦草第4部分同源群染色体代换系SS767,说明中间偃麦草4Ai#2染色体和长穗偃麦草4J染色体可能与纹枯病病情指数降低有关。基因组原位杂交分析结果表明,4Ai#2染色体属中间偃麦草的Js基因组,而长穗偃麦草与纹枯病抗性相关的第4部分同源群染色体属J基因组。虽然纹枯病与眼斑病的发病部位和症状非常相似,但抗眼斑病基因Pch1(Madsen)和Pch2(Cappelle-Desprez)对纹枯病无效。

The objectives of this study were to test the reactions of wheat-Thinopyrum derivatives, wheat （Triticum aestivum L.） cultivars and breeding lines to sharp eyespot （caused by Rhizoctonia cerealis Van der Hoeven） and to understand the relationship between Thinopyrum chromosomes and sharp eyespot resistance. Using field nursery tests, 321 common wheat accessions and 56 wheat-Thinopyrum derivatives were tested in Xuzhou and Nanjing, Jiangsu Province, China. In Xuzhou, none of the accessions was highly resistant, while 52 accessions （including 34 common wheat accessions） were moderately resistant. Six common wheat cultivars, i.e., Xiaonong 8506-1, Xiaoyan 81, Jizhi 4001, Nongda 195, Xuzhou 8913, and Jingdong 3066A-3, had the relative resistance index greater than 0.7. In Nanjing, all the common wheat entries were moderately or highly susceptible. Only five ac- cessions of wheat-Thinopyrum progenies showed moderately resistant reaction. The chromosome addition, substitution, and translocation lines TA3513, TA3516, TA351, and TA3519 involving chromosome 4Ai#2 or 4Ai#2S of Th. intermedium and the chromosome substitution line SS767 involving the homoeologous group 4 chromosome of Th. ponticum had the disease indexes smaller than the susceptible controls Sumai 3 and Yangmai 158, as well the moderately resistant controls Annong 8455 and Ningmai 9. This indicated that the homoeologous group 4 chromosomes from Th. intermedium and Th. ponticum were most likely associated with the reduction of disease indexes. Genomic in situ hybridization using St genomic DNA from Pseudoroegneria strigos as a probe demonstrated that chromosome 4Ai#2 belongs to J^s genome of Th. intermedium and the homoeologous group 4