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综合利用抗性接种鉴定、细胞学分析、SSR分子标记和基因组原位杂交(GISH)技术相结合的方法,对从长穗偃麦草与小麦复合杂交后代中选育的抗条锈病种质系山农87074-519进行了鉴定。结果表明,山农87074-519的根尖细胞染色体数目2n=44,花粉母细胞减数分裂中期I(PMCMI)绝大多数细胞内可观察到22个二价体,平均染色体构型2n=44=21.82Ⅱ+0.36Ⅰ,它与普通小麦中国春杂种F1的多数花粉母细胞内染色体构型为2n=21Ⅱ+1Ⅰ,因此它是1个附加了1对长穗偃麦草染色体的双体异附加系;以假鹅冠草St基因组总DNA作探针进行原位杂交发现山农87074-519的44条染色体中有2条出现黄绿色杂交信号,且杂交信号遍布整条染色体,证明其附加的长穗偃麦草染色体为St基组;利用SSR分子标记技术,在170对SSR引物中筛选出特异引物BARC165,它能稳定地在山农87074-519中扩增出长穗偃麦草特异标记BARC165268;将长穗偃麦草中BARC165的特异扩增片段克隆测序后制备成探针进行原位杂交,可在山农87074-519的间期染色体和有丝分裂中期染色体检测到杂交信号。山农87074-519综合农艺性状较好,对条锈病免疫,其抗性基因为显性,且位于附加的长穗偃麦草St基组染色体上,暂将其表示为YrSt。该种质系在小麦的遗传改良中具有重要利用价值。
The resistance to stripe rust of Zea hazei (Zea mays L.), which was selected from the progenies of long-tailed Agropyron chinensensis and wheat hybrids, was comprehensively studied by means of resistance identification, cytological analysis, SSR molecular markers and genome in situ hybridization (GISH) Farmers 87074-519 were identified. The results showed that the chromosome number of root tip cells in Shannon 87074-519 was 2n = 44, 22 divalent bodies were observed in most cells of metaphase I (PMCMI) in pollen mother cells, with the average chromosome configuration of 2n = 44 = 21.82Ⅱ + 0.36Ⅰ. The chromosomal configuration of most pollen mother cells of Common Spring Wheat F1 was 2n = 21Ⅱ + 1Ⅰ. Therefore, it was a double heterosomal addition with a pair of long-tailed Agropyron elongatum In situ hybridization with total DNA of F. Crown grass St genome as a probe revealed that two of the 44 chromosomes of Shannong 87074-519 appeared yellow-green hybridization signals and the hybridization signals were distributed throughout the whole chromosome, demonstrating that the additional The chromosome of long-ear Agropyron chinense was St-based. The SSR marker was used to screen BARC165 from 170 pairs of SSR primers, which could stably amplify BARC165268 in Shannong 87074-519. The specific amplification fragment of BARC165 from Long-tailed Agropyron was cloned and sequenced. The hybridization signal was detected in interphase chromosome and mitotic metaphase chromosome in Shannong 87074-519. Shannon 87074-519 agronomic traits better, the stripe rust immunity, the dominant gene for resistance, and located in the additional Strobilus elongatus St base genome chromosomes, tentatively expressed as YrSt. This germplasm has important value in the genetic improvement of wheat.