抗白粉病八倍体小偃麦和双体异附加系的鉴定

Identification of Octoploid Trititrigia and Alien Disomic Addition Line with Powdery Mildew Resistance

对从中间偃麦草(Elytrigiaintermedium)与普通小麦品种烟农15杂交后代中选育的双体异附加系山农Line15和八倍体小偃麦山农TE263的形态学、细胞学观察结果表明,它们的主要形态性状介于双亲之间,根尖细胞染色体数目分别为2n=44和2n=56,PMCMⅠ染色体构型分别为2n=22Ⅱ和2n=28Ⅱ;以中间偃麦草总基因组DNA为探针的荧光原位杂交结果表明,山农Line15是在小麦的遗传背景中附加了2条中间偃麦草染色体的双体异附加系;山农TE263是在小麦的遗传背景中附加了14条中间偃麦草染色体,为小麦-中间偃麦草部分双二倍体;白粉病15号生理小种接种鉴定证明,山农TE263对白粉病免疫,山农Line15对白粉病高抗近免疫;其抗性可能均来源于中间偃麦草。RAPD和SSR分析结果表明,在供试的120个随机引物中有1个引物S170(5′-ACAACGCGAG-3′)能在山农Line15中稳定地扩增出中间偃麦草的特异谱带,可用以鉴定山农Line15;在192对SSR引物中,有1对引物Xgdm68-5D(P1:5′-GCCTGACCACTCCCATAAAA-3′;P2:5′-TCGGAAGGGGGACTATACAA-3′)能在山农Line15及其双亲间揭示特异性差异,并初步推测山农Line15中所附加的中间偃麦草染色体可能来源于第5同源群。

Elytrigia intermedium is a promising source of resistance to powdery mildew, one of the most serious diseases of common wheat. To transfer the powdery mildew resistance from Elytrigia intermedium into common wheat, Elytrigia intermedium was used to cross with common wheat cv. Yannong 15. An alien disomic addition line, Shannong Linel5 and an octoploid Trititrigia Shannong TE263, which derived from the progeny of Elytrigia intermedium and common wheat cv.Yannong 15, were identified in morphology, cytology, genome in situ hybridization （GISH） and powdery mildew resistance. The results demonstrated that the main morphological traits of Shannong Linel5, with the chromosome number of 2n = 44 in root tip cells （ Fig. 6） and chromosome configuration of 2n =22Ⅱ at PMC M 1 （ Fig. 7）, and Shannong TE263,with the chromosome number of 2 n = 56 in mot tip cells （ Fig. 3） and chromosome configuration of 2 n = 28 11 at PMC M Ⅰ （Fig.4）, were between that of their parents （Table 1）. The results of GISH with the probe of total genomic DNA of Elytrigia intermedium further proved that Shannong Linel5 was an alien disomic addition line with a pair of Elytrigia intermedium chromosomes （ Fig. 10） in wheat background and Shannong TE263 was a partial amphiloid of wheat and Elytrigia intermedium with 14 chromosomes of Elytrigia intermedium （Fig.9）. Resistance identification in field by using race 15 of E. gramnis f. sp. tritici at adult period showed that Shannong TE263 was immune to powdery mildew and Shannong Line 15 was highly resistant or nearly immune to powdery mildew （Table 3）, their resistant characteristics most probably came from Elytrigia intermedium （Table 3 ） . The results of RAPD analysis and SSR analysis were as follows ：Among 120 random primers , the random primer S170 （5′-ACA ACG CGA G-3′） could reveal the specific band of Elytrigia intermedium （Fig. 11 ） and be used to identify Shannong Line 15. Among 192 pairs wheat mierosatellite primers, Xgdm685D（P1：5′-GCC rIGA CCA CTC CCA TAA AA-Y ;P2：5′- TCG GAA GGG GGA CTA TAC AA-Y） could reveal the specific band of Elytrigia intermedium （Fig. 12） and be used to identify Shannong Linel5, which identified that the added chromosomes of Shannong Line 15 probably came from the 5th homology group of Elytrigia intermedium.