麦类种质资源对大麦黄矮病毒的抗性鉴定及GAV株系的群体遗传变异

发布时间：2018-08-12 08:33

【摘要】：目前,国内小麦种植面积约达2.44×105 hm2,84%主要分布在长城以南的河北、江苏、河南、山东、安徽、湖北、山西、陕西、四川等省,16%分布于长城以北的甘肃、新疆、内蒙古、黑龙江、青海、宁夏等省,是重要的粮食作物,但长期以来,由于植物病毒病的为害,严重影响小麦的产量、品质、口感等。大麦黄矮病毒(BYDV)已成为麦类病害较为严重的一种,有关青海省小麦黄矮病的研究报道较少。因此,本研究对青海省大多种植过的麦类种质资源进行抗性鉴定;对青海省各地主要流行株系BYDV-GAV进行群体遗传变异分析。为以后研究BYDV的寄主互作、抗病性、致病性等奠定基础。本研究主要获得结论如下:1、采用堆测法人工鉴定414份麦类种质资源抗BYDV的抗性鉴定,结果表明:甘A100、川766、陕1059、兰麦-2、灰木头、绿见口、墨沙、加麻白芒麦、克群,灌浆期的病情指数分别为15.33、23.87、23.64、24.53、14.76、22.65、23.67、20.59、21.46均小于25,9份种质资源具有抗性且产量损失较小;甘A101、甘A99、藏515、藏519、木汉麦、群科大白麦、拉胎板麦、小红麦—2、朗县折达25、尼才比芒、木汉麦、尕麦子、铁小麦,拔节期的病情指数大于灌浆期的病情指数,且这13个品种在拔节期至灌浆期期间病状减轻或者消失,表明13份种质资源具有耐病性;剩余392份种质资源灌浆期的病情指数均高于25,表现感病或高感,且产量损失较大。2、通过对BYDV-GAV株系群体遗传变异分析,结果表明:(1)青海省西宁、海西、贵德、循化四个地区2016年小麦黄矮病的病毒检测率达95.83%。(2)cp基因的531个碱基中有23个碱基发生了突变,其中T?C和C?G的颠换达到62.97%,在突变类型中占绝对优势,说明BYDVcp的碱基具有偏好性,在突变过程中偏向于转换的机制。172个氨基酸中有7个氨基酸编码出的蛋白发生了非同义突变,其非同义替代率为4.07%。(3)、4个分离物聚于同一个簇,序列相似性达95.3%-99.9%,与中国BYDV-GAV株系亲源关系较近,可能来源于同一个祖先。(4)、K a/Ks比值小于1,表明进化稳定,BYDV-GAV在青海地区属于负向选择,处于净化状态。
[Abstract]:At present, about 2.44 脳 105hm2O4% of wheat planting area in China is mainly distributed in Hebei, Jiangsu, Henan, Shandong, Anhui, Hubei, Shanxi, Shaanxi, Sichuan and other provinces south of the Great Wall in Gansu, Xinjiang, Inner Mongolia, Heilongjiang, north of the Great Wall. Qinghai, Ningxia and other provinces are important food crops, but for a long time, the yield, quality and taste of wheat have been seriously affected by plant virus disease. Barley yellow dwarf virus (BYDV) has become one of the most serious wheat diseases. Therefore, this study identified wheat germplasm resources most of which had been planted in Qinghai province, and analyzed the population genetic variation of the main prevalent strains BYDV-GAV in Qinghai province. It will lay a foundation for the study of host interaction, disease resistance and pathogenicity of BYDV. The main conclusions of this study are as follows: 1. 414 wheat germplasm resources were artificially identified to be resistant to BYDV by heap test. The results showed that: Gan A100, Chuan766, Shaanxi 1059, Lanmai 2, gray wood, green mukou, Mosha, Triticum mandshurica, Qun. The disease index of grain-filling stage were 15.33C 23.87U 23.64N 24.53n 14.766U 22.665N 23.67N 20.5921.46, all the germplasm resources were less resistant and the yield loss was smaller, Gan A101, Gan A99, Zang 515,519, Muhanmai, Keda white wheat, pullback triticale, Red-wheat -2, Longxian Feida 25, Nimao, Muhan-mai, Muhan-mai, Han-mai. The disease index at jointing stage was higher than that at filling stage, and the disease symptoms of 13 cultivars decreased or disappeared from jointing stage to filling stage, indicating that 13 germplasm resources had disease tolerance. The disease index of the remaining 392 germplasm resources at filling stage was higher than 25, which showed that the germplasm resources were susceptible or highly susceptible, and the yield loss was higher than 0.2. The results showed that: (1) Xining, Hercynian, Guide, Qinghai Province, through the analysis of genetic variation of BYDV-GAV strains, the results were: (1) Xining, Hercynian, Guide, Qinghai Province; The virus detection rate of wheat yellow dwarf disease in Xunhua in 2016 was 95.83. (2) 23 of 531 bases of CP gene were mutated, among which the transversion of TOC and CfG reached 62.97, which was the dominant mutation type of wheat yellow dwarf disease, indicating that the base of BYDVcp has preference. In the process of mutation, the protein encoded by 7 amino acids of 172 amino acids had a nonsynonymous mutation, and its non-synonymous substitution rate was 4.07. (3) the four isolates were clustered in the same cluster. The sequence similarity was 95.3-99.9, which was close to that of the Chinese BYDV-GAV strain, and probably originated from the same ancestor. (4) the ratio of K a/Ks was less than 1, which indicated that the evolutionary stable BYDV-GAV was a negative selection in Qinghai and was in a purified state.
【学位授予单位】：青海大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S435.12

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