小麦-中间偃麦草二体异代换系山农0095的选育及其鉴定

Breeding and Characterization of Wheat-Thinopyrum intermedium Alien Substitution Line Shannong 0095

利用小麦品种烟农15与中间偃麦草直接杂交,以烟农15为回交亲本对其杂种F1回交2次,再经自交3次,从BC2F4中选出种质系山农0095。利用形态学、细胞学、种子醇溶蛋白酸性聚丙烯酰胺凝胶电泳(A-PAGE)、RAPD和GISH等方法对其进行鉴定。结果表明,山农0095平均株高78cm,穗长17.3cm,穗粒数74个,旗叶长36.3cm,旗叶宽3.03cm,茎秆粗壮,多花多实,繁茂性好;其根尖细胞染色体数目为2n=42,花粉母细胞减数分裂中期Ⅰ(PMCMⅠ)染色体构型为2n=21Ⅱ;它与烟农15的杂种F1在减数分裂中期Ⅰ的大多数花粉母细胞能观察到2个单价体,平均染色体构型为2n=20.08Ⅱ+1.84Ⅰ。A-PAGE鉴定结果表明,山农0095在β区出现一条中间偃麦草的特异带;从180个RAPD引物中筛选出一个特异引物S186(5′-GATACCTCGG-3′),能够在山农0095中扩增出一条约900bp中间偃麦草的特异带,标记为S186900;以中间偃麦草基因组DNA为标记探针、中国春基因组DNA为封阻的原位杂交结果进一步表明,山农0095的42条染色体中含有2条完整的中间偃麦草染色体,是小麦-中间偃麦草的二体异代换系。

A new wheat germplasm, Shannong0095, was produced from the hybrids of BC2F4 derived from the progeny of Triticum aestivum cultivar, Yannong15, crossing with Thinopyrum intermedium after the hybrid F1 back-crossing with the Yannong 15 two times and three self-crossings. And it was characterized by using morphology, cytology, alcohol soluble protein-poly acrylamide gel electrophoresis （A-PAGE）, random amplified polymorphic DNA （RAPD） and genomic in situ hybridization （GISH） analysis. The results were as follows： Shannong 0095 had plant height of 78 cm, ear length of 17.3 cm, number of mean spike of 74, flag leaf length of 36.3 cm, flag leaf width of 3.03 cm, stout haulm, and more flowers and more seeds, which showed that it was more luxuriant than that of Yannong 15. The chromosome number of Shannong 0095 in root tip cell was 2n=42 and its chromosome configuration at PMC MI was 2n=21 Ⅱ. Two univalent were observed in most of PMC MI of the hybrids F1 of the crossing between Shannong 0095 and Yannong 15. The mean chromosome configuration of the hybrids F1 was 2n=20.08 Ⅱ＋1.84 Ⅰ. A-PAGE result testified that a specific Thinopyrum intermedium band in β area was observed in Shannong 0095. Among 180 RAPD primers, the prirner S186（5′-GAT ACC TCGG-3′） revealed a specific Thinopyrum intermedium DNA band, about 900bp, that presented in Shannong 0095 and was designed as S 186900. The result of GISH with the probe of Thinopyrum intermedium genomic DNA and the blocker of Chinese Spring （C.S） genomic DNA further conformed that Shannong 0095 contains 2 intact chromosomes of Thinopyrum intermedium and is a wheat-Thinopyrum intermedium alien disomic substitution line.