【作者】 殷贵鸿；

【导师】 王辉；

【作者基本信息】 西北农林科技大学 ， 作物遗传育种， 2009， 博士

【摘要】 小麦条锈病和白粉病分别是由小麦条锈菌(Puccinia striiformis f. sp. tritici)和白粉菌(Blumeria graminis f.sp. tritici)引起的重要病害,严重影响生产发展。选育和合理利用抗病品种是防治小麦条锈病和白粉病最为经济、简单、安全、有效的措施。自从条锈菌优势小种条中32和白粉菌强毒力小种E20出现以后,国内大部分品种都已丧失了抗性。因此,挖掘不同类型的抗病基因,加大开发和应用分子标记,通过分子标记辅助选择,提高抗病育种效率,加快育种进程,对于抗条锈病和抗白粉病小麦品种的选育至关重要。本研究主要分为两部分,一是利用RGAP标记技术筛选与小麦抗条锈病基因YrZH84紧密连锁的分子标记,并对其有效性进行验证;二是对黄淮麦区大面积推广的小麦新品种济麦22所携带的抗白粉病基因进行遗传分析和分子标记定位,为品种的合理利用和分子标记辅助育种提供理论依据。主要结果如下:1、利用1711对RGA(Resistance gene analog, RGA,抗病基因同源序列)引物组合对黄淮麦区骨干亲本周8425B与中国春杂交F2代522个单株进行抗病鉴定和分子标记分析,其中清晰、稳定可重复的引物对有40个。用这40对引物组合检测60个抗病株(IT =2)和60个感病株(IT =4),表明交换率在1%以下的有1对,该标记命名为Xrga-1,用于检测整个F2群体。结果表明,Xrga-1与YrZH84紧密连锁,遗传距离0.8 cM。经挖胶回收,克隆测序,其RGA片段长度为343 bp。BLAST分析表明,该RGA序列与已克隆的大麦抗秆锈病基因Rpg1核苷酸序列同源性为93%,与大麦抗白粉病基因Mla家族的核苷酸序列同源性为92%。这些研究结果对小麦抗条锈病分子标记辅助育种和YrZH84基因克隆有重要作用。2、用与小麦抗条锈病基因YrZH84两侧紧密连锁的RGAP标记Xrga-1(0.8 cM)和SSR标记Xcfa2040-7B(1.4 cM)检测周8425B的48个衍生品种和黄淮麦区的9个主推品种,结果显示,在周麦11、周麦17、周麦20、周麦22、矮抗58、04中36、源育3号、05中37、宛抗18、豫展10号等10个品种中,YrZH84两侧标记都存在,系谱分析发现它们都是周8425B的衍生后代,结合田间抗病性鉴定结果,确定它们携带YrZH84基因。而其他38个周8425B的衍生品种表现感病,且没有检测到两侧标记的特异性片段(343、238bp),说明YrZH84基因在这些品种选育过程中已丢失。建立了小麦抗条锈病新基因YrZH84分子检测体系,可用于抗条锈病的分子标记辅助育种,聚合多个抗病基因,提高品种的持久抗性。3、用白粉菌强毒力小种E20对济麦22与感病亲本中国春杂交群体的228个F2抗、感分离单株和99个F2;3家系进行苗期接种鉴定,分析表明,济麦22携带1个显性抗白粉病基因,暂命名为PmJM22,系谱分析和亲本接种鉴定表明,该抗性基因可能来源于英国的普通小麦TJB259/87。运用SSR和EST标记技术及分离群体分组分析法(BSA),将其定位在2BL染色体上,与距其最近的SSR标记Xwmc149-2B和EST标记CD490485-2B的遗传距离分别为7.7 cM和18.7 cM。分析2BL上其它抗白粉病基因的来源、染色体位置和抗性反应,表明PmJM22与Pm6、Pm26、Pm33和MlZec1都不相同,很可能是一个新的抗白粉病基因。为小麦抗白粉病育种提供了抗病基因。4、用白粉菌强毒力小种E20接种鉴定2008-2009年度黄淮麦区预备试验的79份小麦新品种、2份对照品种以及黄淮麦区7个主推品种。结果表明,在79份小麦新品种中,对E20表现抗病的新品种有4个,占5.1%,其中豫农209、远594、金禾9123表现高抗,洛麦27表现中抗;对E20表现感病的品种75个,占94.9%,包括表现中感的为涡02197等22个品种,表现高感的洛麦22等53个品种。2份对照品种周麦18、偃展4110均为中感。生产上主推品种对E20表现高抗的有周麦22、济麦22、矮抗58,表现中感的为邯6172,表现高感的为新麦18、济麦19和石4185。系谱分析表明,黄淮麦区新育成品种的亲缘关系较近,遗传基础狭窄,抗病基因单一,是导致这些品种白粉病抗性差的主要原因。更多还原

【Abstract】 Stripe rust and powdery mildew, caused by Puccinia striiformis f. sp. tirtici and Blumeria graminis f. sp. tritici, respectively, are the most damaging diseases in common wheat (Triticum aestivum L). Breeding and utilization of resistant varieties are the most economical and effective way to control the disease. After the emergence of the highly virulent race CYR32 of Puccinia striiformis f. sp. tirtici and highly virulent isolate E20 of Blumeria graminis f. sp. tritici, most of Chinese wheat varieties have lost their resistance to stripe rust and powdery mildew, and thus vulnerable to the two diseases under suitable climate. Therefore, identification of stripe rust and powdery mildew resistance genes are essential for breeding resistant wheat cultivars.The objectives of this study were to identify the molecule markers tightly linked to wheat stripe rust resistance gene YrZH84 employing the resistance gene-analog polymorphism (RGAP) markers, and validate the availability of the markers, and to map the powdery mildew resistance gene in Jimai 22. The molecular markers identified in this study can be used for marker-assisted selection in wheat breeding. The results are summarized as follows:1. A total of 522 F2 plants derived from the cross Zhou 8425B/Chinese Spring and their parents were used for linkage analysis. In all, 1711 RGA primer combinations were used to test the parents, as well as the resistant and susceptible bulks. Of the 116 RGA primer combinations, 40 generated repeatable and clearly polymorphic bands between the resistant and susceptible bulks. One RGAP marker, designated Xrga-1, showed a tight linkage with the stripe rust resistance gene YrZH84, with a genetic distance of 0.8 cM. The DNA sequence of the RGA fragment was in a size of 343 bp. BLAST analysis indicated that the Rpg1 showed 93% of identical nucleotide sequences to that of barley stem rust resistance gene Rpg1, and 92% to that of barley powdery mildew resistance gene Mla homology family. These results will greatly benefit for the marker-assisted selection and cloning of the resistance gene YrZH84.2. Forty-eight varieties derived from Zhou 8425B and seven important commercial varieties from the Huang and Huai winter wheat region were tested by the YrZH84 flanking RGAP marker Xrga-1 and SSR marker Xcfa2040. The results indicated that the specific 343-bp PCR fragment generated by the Xrga-1 and 238-bp by Xcfa2040 were detected in 10 varieties, i.e. Zhoumai 11, Zhoumai 17, Zhoumai 20, Zhoumai 22, Aikang 58, 04 Zhong 36, Yuanyu 3, 05 Zhong 37, Yuankang 18 and Yuzhan 10, which showed resistant to the prevalent race CYR32 of Puccinia striiformis f. sp. tirtici and should contain the stripe rust resistance gene YrZH84 based on resistance identification result and the pedigree analysis. In contrast, the other 38 derivatives of Zhou 8425B, susceptible to the race CYR32, did not amplify the corresponding specific PCR fragment, indicating that the resistance gene YrZH84 were lost during the development of these varieties. These results showed that the marker Xrga-1 and Xcfa2040 can be effectively used for the test of the stripe rust resistance gene YrZH84 and marker-assisted selection.3. A total of 228 F2 plants and 99 F2;3 lines derived from the cross Jimai 22/Chinese Spring and their parents were used for the identification of powdery mildew resistance gene in the Jimai 22 using a highly virulent isolate E20 of Blumeria graminis f. sp. tritici, and SSR and EST markers. The result showed that Jimai 22 carried a dominant powdery mildew resistance gene, designated PmJM22 tentatively. Pedigree analysis and resistance test indicated that this gene may be originated from an English common wheat line TJB 259/87. Molecular marker analysis indicated that the powdery mildew resistance gene PmJM22 was mapped on chromosome 2BL, and linked to SSR marker Xwmc149-2B and EST markers CD490485-2B with genetic distances of 7.7 cM and 18.7 cM, respectively. Based on the origins, chromosome locations and reaction patterns of the powdery mildew resistance genes on chromosome 2BL, PmJM22 is likely a new powdery resistance gene that is different from Pm6, Pm26, Pm33 and MlZec1.4. Seventy-nine advanced wheat lines participating in the national field trials for the Huang Huai winter wheat region and two control varieties in 2008-2009 cropping season, and seven important commercial varirties were used for seedling test to the isolate E20. The results showed that 4 lines were resistant to E20, accounted for 5.1%, in which Yunong 209, Yuan 594 and Jinhe 9123 were highly resistant and Luomai 27 moderately resistant, whereas 75 were susceptible to E20 with a percentage of 94.9%, including 22 moderately susceptible and 53 highly susceptibile lines. Two control varieties Zhoumai 18 and Yanzhan 4110 were moderately susceptibile to E20. Three of the seven commercial varirties were highly resistant, i.e., Zhoumai 22, Jimai 22 and Aikang 58, and Han 6172 were moderately susceptibile, while Xinmai 18, Jimai 19 and Shi 4185 were highly susceptibile. Pedigree analysis indicated that the genetic basis of these new breeding lines was rather narrow, and thus it is essential to find some new powdery resistance genes for the development of resistant wheat varieties.更多还原