Ayala-Navarrete L, Tourton E, Mechanicos A A, Larkin P J
CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia.
Genome. 2009 Jun;52(6):537-46. doi: 10.1139/g09-028.
Resistance to both barley yellow dwarf virus (BYDV) and cereal yellow dwarf virus (CYDV) has been demonstrated in wheat genetic stocks with Thinopyrum intermedium chromatin. A number of resistance-bearing translocations have been reported on chromosome arm 7DL from two independent Th. intermedium sources; one source is the addition line L1 and the other is the spontaneous substitution line P29. Another source of resistance in wheat cytogenetic stocks is available as a 2Ai(2D) substitution line. We used a set of 38 molecular markers and the available deletion stocks to compare the size of the 7DL translocations more comprehensively than has been done previously. We also compared the efficacy of BYDV resistance of the various genetic stocks both before and after transfer to a common genetic background. TC14 was confirmed as carrying the smallest translocation, replacing about 20% of the distal end of 7DL. TC5 and TC10 had 90% of the chromosome arm replaced by Th. intermedium chromatin; the proximal 10% corresponded to wheat chromatin. YW642 appeared to have the whole 7DL replaced by Th. intermedium chromatin, as confirmed by the co-dominant marker cfd68 mapping on the bin nearest the centromere. Translocation line P961341 had bins 3, 7, and 8 replaced by Th. intermedium chromatin, making this the second smallest translocation with BYDV and CYDV resistance. The translocation sizes reported here differ from some of the previous estimates. The translocated Th. intermedium segments appeared to be bigger than the replaced wheat 7DL fragments. All the resistances derived from the L1 and P29 group 7 chromosomes and the 2Ai#2 chromosome were effective in reducing the number of infected plants and the mean virus titre, regardless of the background. Some evidence is discussed suggesting the long arm of the Th. intermedium group 7 chromosome 7Ai#1 carries two resistances, the distal Bdv2 and a proximal second gene.
在含有中间偃麦草染色质的小麦遗传材料中已证实对大麦黄矮病毒（BYDV）和谷类黄矮病毒（CYDV）均具有抗性。已报道了来自两个独立中间偃麦草来源的7DL染色体臂上的多个携带抗性的易位系；一个来源是附加系L1，另一个是自发代换系P29。小麦细胞遗传材料中的另一个抗性来源是作为2Ai(2D)代换系存在。我们使用一组38个分子标记和现有的缺失系，比以往更全面地比较了7DL易位系的大小。我们还比较了各种遗传材料在转移到共同遗传背景前后对BYDV抗性的效果。TC14被确认为携带最小的易位，取代了7DL远端约20%的区域。TC5和TC10有90%的染色体臂被中间偃麦草染色质取代；近端10%对应于小麦染色质。YW642似乎整个7DL都被中间偃麦草染色质取代，这通过在最靠近着丝粒的 bins 上共显性标记cfd68的定位得到证实。易位系P961341的 bins 3、7和8被中间偃麦草染色质取代，这使其成为具有BYDV和CYDV抗性的第二小易位系。这里报道的易位大小与一些先前的估计不同。易位的中间偃麦草片段似乎比被取代的小麦7DL片段更大。源自L1和P29第7组染色体以及2Ai#2染色体的所有抗性在减少感染植株数量和平均病毒滴度方面均有效，无论背景如何。讨论了一些证据表明中间偃麦草第7组染色体7Ai#1的长臂携带两种抗性，远端的Bdv2和近端的第二个基因。
