Steffan Philipp Matthias, Torp Anna Maria, Borgen Anders, Backes Gunter, Rasmussen Søren K
Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark.
KWS LOCHOW GMBH, Ferdinand-von-Lochow-Straße 5, 29303, Mons, Germany.
Theor Appl Genet. 2017 May;130(5):1031-1040. doi: 10.1007/s00122-017-2868-6. Epub 2017 Feb 25.
The Bt9 resistance locus was mapped and shown to be distinct from the Bt10 locus. New markers linked to Bt9 have been identified and may be used to breed for resistance towards the seed-borne disease. Increasing organic wheat production in Denmark, and in other wheat-producing areas, in conjunction with legal requirements for organic seed production, may potentially lead to a rise in common bunt occurrence. As systemic pesticides are not used in organic farming, organic wheat production systems may benefit from genetic resistances. However, little is known about the underlying genetic mechanisms and locations of the resistance factors for common bunt resistance in wheat. A double haploid (DH) population segregating for common bunt resistance was used to identify the chromosomal location of common bunt resistance gene Bt9. DH lines were phenotyped in three environments and genotyped with DArTseq and SSR markers. The total length of the resulting linkage map was 2882 cM distributed across all 21 wheat chromosomes. Bt9 was mapped to the distal end of chromosome 6DL. Since wheat common bunt resistance gene Bt10 is also located on chromosome 6D, the possibility of their co-location was investigated. A comparison of marker sequences linked to Bt9 and Bt10 on physical maps of chromosome 6D confirmed that Bt9 and Bt10 are two distinct resistance factors located at the distal (6DL) and proximal (6DS) end, respectively, of chromosome 6D. Five new SSR markers Xgpw4005-1, Xgpw7433, Xwmc773, Xgpw7303 and Xgpw362 and many SNP and PAV markers flanking the Bt9 resistance locus were identified and they may be used in the future for marker-assisted selection.
Bt9抗性位点已被定位，并显示与Bt10位点不同。已鉴定出与Bt9连锁的新标记，可用于培育对种子传播病害的抗性。丹麦及其他小麦产区有机小麦产量的增加，以及有机种子生产的法律要求，可能会导致网腥黑穗病发生率上升。由于有机农业不使用内吸性农药，有机小麦生产系统可能受益于遗传抗性。然而，对于小麦中抗网腥黑穗病抗性因子的潜在遗传机制和位置知之甚少。利用一个分离抗网腥黑穗病的双单倍体（DH）群体来鉴定抗网腥黑穗病基因Bt9的染色体位置。DH系在三种环境中进行表型分析，并用DArTseq和SSR标记进行基因分型。所得连锁图谱的总长度为2882厘摩，分布在所有21条小麦染色体上。Bt9被定位到6DL染色体的远端。由于小麦抗网腥黑穗病基因Bt10也位于6D染色体上，因此研究了它们共定位的可能性。在6D染色体物理图谱上对与Bt9和Bt10连锁的标记序列进行比较，证实Bt9和Bt10是两个不同的抗性因子，分别位于6D染色体的远端（6DL）和近端（6DS）末端。鉴定出了五个新的SSR标记Xgpw4005-1、Xgpw7433、Xwmc773、Xgpw7303和Xgpw362，以及许多位于Bt9抗性位点侧翼的SNP和PAV标记，它们未来可用于标记辅助选择。
