多属杂种主要是利用不同种属染色体间的重组或结构重排

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2017-04-21 17:47:55 转载

摘要多属杂种主要是利用不同种属染色体间的重组或结构重排，产生集合多种和属优良基因的个体，通过筛选、鉴定和选育，最终得到以小麦(Triticum aestivum)性状为主，综合多个有益基因、抗性的种质资源或直接育成新品种。为了探讨多属杂交的细胞遗传规律和选育大穗，籽粒饱满和抗病等优良农艺性状的小麦-偃麦草-黑麦多属杂种新材料。本研究利用形态学和分子细胞遗传学研究方法，对八倍体小偃麦(Trititrigia)麦草8号(AABBDDEE, 2n=56)与六倍体小黑麦(triticale (×Triticosecale))哈师209(AABBRR, 2n=42)杂交F6代部分株系进行分析鉴定。形态学鉴定结果表明，F6株系形态特点差异明显，可分为小黑麦类型、普通小麦类型和中间类型。5个小黑麦类型株系，抗倒伏，大穗多粒，花粉母细胞减数分裂观察具有单价体，有4个株系千粒重超过40 g；3个株系14-4、3-29-3和h-29为带有R、E组染色体组遗传成份的六倍体小黑麦；其中，株系14-4籽粒饱满，千粒重达到47.6 g，明显优于亲本哈师209。8个普通小麦类型株系，熟期正常，根尖染色体数为42，有5个株系带有R组染色体成分。其中株系14-22带有R组小片段易位；株系w-16带有E组染色体易位和代换。7个中间型株系全部带有R组染色体组遗传成分，植株高大，可达94~120 cm；分蘖多，可达到15个；多花多粒，小穗数可达16~36；其中，株系h-7主穗粒数达122个，包壳，不易脱粒；株系11-26带有R组小片段易位；株系11-21-2除具有R组染色体成分外，带有E组染色体，但染色体数为52，尚不稳定。本研究得到的小黑麦类型株系14-4、3-29-3和h-29为小麦-偃麦草-黑麦三属杂种新种质，可为小黑麦品种选育和创制小麦多属杂交新种质提供理论和材料基础。	服务把本文推荐给朋友加入我的书架加入引用管理器E-mail AlertRSS作者相关文章王春阳高继迪刘佳莹张媛媛宋维富杨雪峰宋庆杰李集临张延明
关键词：小麦, 多属杂交, 偃麦草, 黑麦, 分子标记
Abstract：The trigeneric hybridization is mainly produced by recombination or structural rearrangement among chromosomes of different species, and they are the individuals with excellent gene set. Through screening, identification and breeding, the wheat traits were obtained, as well as genes, resistance to germplasm or direct breeding of new varieties. So far, the domestic and foreign scholars have been a large number of polygeneric hybrids. Its descendants were analyzed and the results showed that the offspring differentiation of the hybridization was extremely complicated, which generated some new germplasm for the improvement of wheat genetics. In this study, polygeneric hybrid was produced by an octoploid trititrigia (wheatgrass 8, AABBDDEE, 2n=56) and a hexaploid triticale (Hashi 209, AABBRR, 2n=42). Wheatgrass 8 of the male parent was obtained from the hybridization of Chinese Spring and Thinopyrum intermedia. Hashi 209 of the female parent was final election in 1996 and called "Nongqing 2" by Heilongjiang Provincial Variety Approval Committee, which was cultivated in 1990 using the hybridization between "triticale 2" (octoploid triticale, bred by Academician Bao Wenkui from Chinese Academy of Agricultural Sciences) and "Rosner"(a hexaploid triticale). Then, a part of hybrid F6 generations of polygeneric hybrid were analyzed and identified by morphological and molecular cytogenetic methods, which was aimed at discussing the cytogenetics' rule of polygeneric hybrid and breeding hybrids of Triticum-Thinopyrum-Rye with the important agronomic traits, such as a large spike, more flowers and grains, and resistance to disease. It will provide the basic material for the improvement of Triticale and Triticum. The morphological results showed that the significant differences of morphological characteristics were divided into triticale type, normal wheat type and intermediate type. There were 5 lines of triticale type, which were lodging resistance and large spikelets. Their pollen mother cell meiosis was observed with the univalent, and the thousand kernel weight was more than 40 g in 4 lines. The results of molecular marker and genome in situ hybridization showed that 3 lines (14-4, 3-29-3, and h-29) were hexaploid triticale with R and E chromosomes. The kernel of line 14-4 was full and the thousand-grain weight was 47.6 g, which was better than its parental Hashi 209. There were 8 lines of normal wheat types. Their maturity was normal and the chromosome number of root tip cell was 42. There were 5 lines with the genetic components of R group chromosome and line 14-22 carried the chromosomal translocation of R genome, additionally, line w-16 carried the chromosomal translocation and substitution of E genome. There were 7 lines of intermediate type and all lines had the genetic components of R genome. The plants were height (94~120 cm), more tillers (5~15) and grains. The spikelet number was from 16 to 36. The kernel number of main spike in line h-7 was 122 and the threshing was difficult. Line 11-26 carried the chromosomal translocation of R genome. Besides of carrying the genetic components of R group chromosome, line 11-21-2 carried E chromosomes, but the chromosome number of root tip cell was 52. It was less the genetic instability. Line14-4, 3-29-3 and h-29 that obtained from the research were new germplasms of Triticum-Thinopyrum-Rye, which provides theoretical and material bases for breeding triticale and creating wheat polygeneric hybrids.