【作者】 董永梅；

【导师】 柴守诚；

【作者基本信息】 西北农林科技大学 ， 种子工程， 2007， 硕士

【摘要】 我国地域辽阔,生态环境多样。经过长期的种植,在自然和人工双重选择下形成了丰富的小麦地方品种。我国国家种质库中保存的地方小麦品种多达13902份,是其他国家不能比拟的。中国小麦地方品种具有丰富的遗传变异类型,具有高度广适性和许多优良的农艺性状,是遗传育种发掘新基因的重要基因库,因此研究小麦地方品种对于现代小麦育种和品种改良具有重要意义。本文选取5个上世纪五六十年代大面积推广小麦地方品种,每个品种选60个株系,利用条锈菌单孢菌系检测不同株系条锈病反应型差异;同时采用半粒法无胚部分种子检测小麦地方品种群体内高分子量麦谷蛋白亚基组成;有胚部分发苗,分单株提取叶片DNA。选用42对SSR分子标记检测品种内部等位基因的多样性,试图从不同水平上了解地方品种内等位基因变异情况;另外还分析了来自我国22省市和地区的200份小麦地方品种的高分子量麦谷蛋白亚基组成情况。本试验得到以下研究结果:(1)地方品种群体内等位基因的遗传多样性研究条锈病检测结果表明:5个地方品种和对照对两个条锈病生理小种的反应型存在着分离,同一小种检测结果发现不同小麦地方品种群体内的反应型分离情况各不相同。CY17抗性检测中各地方品种内存在3到7种反应型。三月黄中有7种反应型,是反应型最为丰富的材料,也是唯一检测到抗感分离的地方品种。CY24小种检测供试材料发现所有地方品种反应型介于2～8种不等,抗性分离最大的葫芦头表现出8种反应型。其中大粒半芒内未发现抗感分离,其它4份地方品种内均存在不同程度的抗感分离。HMW-GS分析表明:五个地方品种及对照材料共检测出13种亚基组合.不同材料内亚基组合数1～4种不等,变异最丰富的是大粒半芒和葫芦头,品种内部高分子量谷蛋白亚基组成有4种。小麦地方品种三月黄品种内亚基组成一致。其余地方品种和育成品种的高分子量谷蛋白亚基变异在2～3之间。SSR研究结果表明:42对引物中40对在不同材料中表现出多态性,2对在所有材料中表现单态。七个材料中共检测到289个等位位点,每对引物检测到的1到17个不等,平均每对6.88个。单个引物在材料内部检测到的等位变异0～9个不等;引物位点的多态信息含量指数,变幅在0.000~0.304,平均为0.141。引物BARC171的多态信息含量指数最高;5个地方品种内PIC指数变幅为0.0435~0.328,平均为0.187。大粒半芒PIC指数最高,辉县红最低。两个育成品种PIC指数平均值为0.036。HMW-GS研究与SSR分析比较表明:地方品种内高分子量麦谷蛋白亚基类型增加的同时,SSR分子标记检测到的等位变异数也在增加。小麦地方品种在HMW-GS组成上多态性越高,其整个基因组上检测到的等位基因变异也越丰富。高分子量麦谷蛋白由位于小麦第一部分同源染色体长臂上基因控制编码,因此推断地方品种内其变异趋势和整个基因组上SSR检测到的等位基因变异趋势一致。(2)小麦地方品种间亚基组成多态性研究200份小麦地方品种中检测到35种亚基组合,亚基等位变异丰富。其中Null,7+8,2+12组合的材料有118份,频率达到了59%,其余的组合频率均低于10%。在所有的地方品种中还发现一些特殊亚基,对其功能有待于进一步研究。依据上述初步研究结果本文得出以下结论:(1)HMW-GS,SSR,以及条锈病群体抗性分析分别从基因表达产物,基因组重复序列,功能基因上验证了地方品种内等位基因遗传多样性的存在。地方品种内高分子量麦谷蛋白亚基组成分析表明地方品种是一个由不同HMW-GS构成个体组成的遗传平衡群体,即异质性遗传平衡群体。(2)鉴于上述结论,在研究小麦地方品种时不仅要对不同的品种进行研究,也应对品种个体予以关注。在地方品种的收集保存上应保证一定的群体量,以保证品种遗传多样性的完整性。更多还原

【Abstract】 China has a wide terrain and many types of entironments. After planting for a long period, many wheat (Triticum aestivumL.) landraces formed. At present, 13902 wheat landraces were conserved in the national bank of germplasm and resources, which was much more than any other country. Chinese wheat landraces possessed eurytopicity and excellent characters, and they are deemed as the useful genebank for wheat breeding, so interrelated researches are meaningful to wheat breeding and modern variety improvement.Reaction type diversities among the populations of 5 widegrown wheat landraces were analyzed. At the same time, sixty seeds of every landrace were cut into two parts. The half kernels without embryos were crushed to analyze glutenin composition using sodium dodecyl sulphate polyacrylamide-gel electrophoresis (SDS-PAGE). The other half kernels with embryos were germinated and the bulked leaf samples were used to extract DNA for SSR analysis. 42 pairs of SSR primers were used to detect the allelic diversity within wheat landraces; meanwhile, the HMW-GS composition of 200 wheat landraces that originated from 22 provinces and regions were also determined.(1)Diversity in alleles whthin the population of wheat landraces from chinaThe stripe rust resistant analysis indicated that there were various difference in response types to stripe rust among every population of wheat landraces and cultivars. The segeragations of response types to the same physiological race were different among different landrace colony. Infection types to CY17 within landraces ranged from 3 and 7, 7 infection types were determined witnin‘Sanyuehuang’, which was the landrace with the most response types. The infection types to CY24 of each material were 2 to 8,‘Hulutou’was the most. There was 1 infectoin type within‘Dalibanmang’, the other 4 landraces all had 4 infection types.HMW-GS analysis indicated that 13 types of glutenin patterns were observed in all materials, and the number of HMW-GS composition within each wheat landrace ranged from 1 to 4. The richest variations on HMW-GS combination were observed in wheat landraces‘Dalibanmang’and‘Hulutou’with 4 types of glutenin patterns. No variation was determined in‘Sanyuehuang’, HMW-GS combinations of other materials were between 2 and 3.SSR result showed that 40 of the 42 primer pairs were polymorphic among different accessions. A total of 289 alleles were detected with an average of 6.88 and a range of 1 to17 alleles for each primer pair. The allelic number that each primer pair can detect in every landrace varied from 0 to 9. The PIC indexes of all primer pairs ranged from 0.000 to 0.304 with 0.141 in average. The highest PIC index was found by primer barc171. The PIC indexes within 5Landraces ranged from 0.0435to 0.328, while its average was 0.187.The highest PIC was observed in‘Dalibanmang’and theowest was in‘Huixianhong’.Comparison between glutenin banding patterns and SSR analysis indicated that the number of allelic variance observed by SSR and the allelic diversity on whole wheat genome were all increased as the adding of the HMW-GS combination. HMW-GS were controlled by genes at theLong arms of the chromosomes 1A、1Band1D,so we concluded that the diversity of HMW-GS combination and the allelic diversity on wheat genome has a same change trend(2)Research of glutenin composition diversity among 200 wheatlandraces.Thirty-five kinds of glutenin patterns were observed among 200 wheat landraces. Null,7+8,2+12 was the most frequent subunit combination that was detected in 118 landraces ( 59%). The frequencies of the other subunit combinations are all less than 10%.Some rare HMW-GS also been determined, and need to be researched ulteriorlyBased on the results above, we conclude that: (1) a high percentage of Chinese wheat landraces are genetically heterogeneity populations based on glutenin composition analysis, SSR and the resistance to strip rust; (2) Based on the genetic heterogeneity of wheat landraces, a large population should be conserved in order to maintain the genetic completeness during their collection and conservation.更多还原