【作者】 张文涛；

【导师】 陈新宏； 武军；

【作者基本信息】 西北农林科技大学 ， 作物遗传育种， 2011， 硕士

【摘要】 小麦野生近缘种属植物中蕴藏着多种栽培品种所不具备的优良基因,野生近缘种属优良外源基因的导入及外源遗传物质的鉴定和利用,对丰富小麦育种基础和拓宽遗传改良途径具有重要意义。华山新麦草(Psathyrostachys huashanica Keng.)是小麦重要野生近缘种质资源种,具有早熟、矮杆、抗病、抗逆等优良特点。本研究以华山新麦草与普通小麦7182杂交获得的109株小麦-华山新麦草衍生后代为材料,综合利用细胞学、基因组原位杂交(GISH)、生化标记和DNA分子标记技术,对其进行外源遗传物质鉴定;在追踪被导入的外源染色体遗传稳定的基础上,确定添加在普通小麦背景中的华山新麦草染色体的部分同源性关系。另外,从普通小麦-华山新麦草衍生后代中,经多代选育分离出稳定遗传的大穗多花种质B46,以表型特征观察为基础,通过细胞学镜鉴结合基因组原位杂交(GISH)对其进行外源鉴定,研究和分析该大穗材料的大穗多花遗传特性和染色体组成。其主要结果如下:(1)对普通小麦-华山新麦草衍生后代的细胞学镜鉴结果表明,109个小麦-华山新麦草衍生后代中,其中有53个材料染色体数目为2n=42,26个材料染色体数目为2n=43,30个材料染色体数目为2n=44;对30个2n=44的材料染色体GISH分析结果表明,11个材料为二体异附加系,19个材料为双单体异附加系。小麦-华山新麦草二体附加系中导入的成对华山新麦草染色体能够较稳定地遗传给后代。(2)从定位于小麦七个部分同源上的78对EST-SSR引物中筛选出12对可用于追踪普通小麦背景中华山新麦草染色体的特异分子标记。运用筛选出的特异分子标记对11个普通小麦-华山新麦草二体异附加系进行外源染色体部分同源关系的鉴定。根据PCR检测和醇溶蛋白电泳谱带分析,异附加系5、附加系6和9、附加系7和11、异附加系2、异附加系8中附加的华山新麦草染色体分别与小麦第1、2、5、6、7部分同源群染色体有部分同源关系;附加系4中外源染色体涉及第2、4部分同源群染色体重排;附加系10中外源染色体涉及第4、7部分同源群染色体重排。(3)通过普通小麦(Triticum aestivum L.)与华山新麦草(Psathyrostachys huashanica)杂交、回交和自交,连续多代选育出遗传稳定的大穗多花种质B46,对其进行农艺性状调查、细胞学观察结合GISH检测的综合鉴定。结果表明,B46形态学特征表现大穗多花特性,穗长12cm左右,小穗达23个,小穗粒数平均6个;其根尖细胞染色体计数为2n=44;根尖原位杂交(GISH)及减数分裂中期Ⅰ染色体的基因组原位杂交(GISH)显示,B46附加一对来自于华山新麦草的同源染色体。由此可以确定B46为小麦-华山新麦草的二体异附加系,其综合农艺性状优于小麦亲本,可作为培育高产小麦品种的优良种质材料。普通小麦-华山新麦草二体异附加系中外源染色体部分同源关系的确定及大穗多花种质的创制,为进一步挖掘和利用华山新麦草优良基因、丰富小麦遗传种质资源、开发和利用华山新麦草这一珍稀濒危物种具有重要意义。更多还原

【Abstract】 The wild relatives of wheat contain many valuable genes without in wheat. The transfers of alien genes from related species and genera into common wheat, and the identification and utilization of alien genetic chromatin in wheat, will enrich the foundation of wheat breeding and provide new approaches for wheat improvement. Psathyrostachys huashanica Keng(2n=2x=14,NsNs) is the vital wild germplasm resources for cultivated wheat, Which is characterized by early maturity and special resistantance under stresses.In this paper, 109 derivative offspring from hybridizing between Triticum aestivum L cv. 7182 and P.huashanica were characterized using cytology, genomic in situ hybridization (GISH), protein electrophoresis and DNA molecular markers technology to detection the alien genetic chromatin. The investigations of homoeologous grouping of P.huashanica chromosomes were conducted on the basis of tracing transferred genetic stability of alien chromosomes in the wheat background. Moreover, a large-spike and fertile florets wheat germplasm, B46, was obtained from the offspring of the hybridizing between Triticum aestivum L cv. 7182 and P.huashanica. Main results are as follows:(1)The cytological observation showed 53 plants with chromosome constitution of 2n=42, 26 plants with chromosome constitution of 2n=43, 30 plants with chromosome constitution of 2n=44. The mitotic and meiotic GISH analysis of 30 plants( 2n=44), indicated that 11 plants were wheat-P. huashanica disomic addition lines, 19 plants were wheat-P. huashanica double monosomic addition lines . It has been proven that exotic chromosome pairs could be steadily transmitted into the descendants.(2)Seventy-eight pairs of EST-SSR primers from seven homoeologous groups of Triticeae were screened specific markers for P.huashanica chromosomes and revealed the homoeologous relationship between P.huashanica chromosomes of wheat-P. huashanica disomic addition lines and chromosomes of common wheat .The result showed that 12 pairs of primers can be preliminary used as P. huashanica chromosomes specific molecular markers. The homoeologous relationship between common wheat and P.huashanica chromosomes of wheat-P. huashanica disomic addition lines was analyzed by means of PCR and gliadin bands analysis showed that P.huashanica chromosomes of 11 wheat-P. huashanica disomic addition lines were grouped into homoeologous group 1, 2, 4, 5, 6and 7. The added chromosomes in disomic addition line 5 were grouped into homoeologous group 1; addition line 6 and 9 were grouped into homoeologous group 2; addition line 7 and 11 were grouped into homoeologous group 5; addition line 2 were grouped into homoeologous group 6; addition line 8 were grouped into homoeologous group 7, respectively. While chromosomal rearrangement of homoeologous group 2 and homoeologous group 4 was detected in the addition line 4, the chromosomal rearrangement between homoeologous group 4 and homoeologous group 7 was identified in the addition line 10.(3) Exploration on the genetic material of large-spike and fertile florets wheat germplasm B46, which was obtained by selection the offspring of hybridizing, back-crossing and self-crossing between Triticum aestivum L cv. 7182 and P.huashanica by means of combined morphological observation, cytological analysis and genomic in situ hybridization (GISH) analysis after years of backcross and selfing. The result shows that B46 is a large-spike and fertile florets wheat with12cm ear length, 23 spikelets per spike and 6 florets per spikelet. There are 44 chromosomes in the root tip cell of B46 and the GISH analyses revealed that B46 contains a pair of homologous P.huashanica chromosomes. Ultimately, B46 was a wheat-P.huashanica hybridization disomic addition line, and of comprehensive agronomy traits, which can be utilized as good resource for cultivating wheat varieties of high yield.These reseach will be crucial to exploit the advantageous genes of the endangered species P. huashanica, improve and enrich conventional germplasm in further study.更多还原