Institute of Biotechnology in Plant Production, University of Natural Resources and Life Sciences, Konrad-Lorenz-Strasse 20, Tulln, Vienna, 3430, Austria.
Institute of Plant Breeding, University of Natural Resources and Life Sciences, Konrad-Lorenz-Strasse 24, Tulln, Vienna, 3430, Austria.
Theor Appl Genet. 2023 Sep 7;136(9):207. doi: 10.1007/s00122-023-04452-5.
A major QTL on chromosome 6DL corresponding to bunt resistance gene Bt11 was identified in four mapping populations generated through crosses with Bt11-carriers PI 166910 and M822123. Common bunt in wheat has witnessed a renaissance with the rise of organic agriculture that began in the 1980s. The abandonment of systemic fungicides in organic farming, together with a lack of resistant cultivars, has led to wide-spread problems due to common bunt infections. Knowledge about genetic sources for resistance is still scarce and only few of the known bunt resistance factors are currently used in breeding. We therefore aimed to map the resistance factor harboured by the Turkish landrace PI 166910, which is the resistance donor for the Bt11 bunt differential line. Four mapping populations (MPs) with 96-132 recombinant inbred lines (RILs) were phenotyped for common bunt resistance over 2, 3 or 4 years with one or two local bunt populations and genotyped with the 25K SNP array. A major bunt resistance locus on the distal end of chromosome 6D designated QBt.ifa-6DL was identified in all MPs and experiments. Additional QTL contributing to resistance were detected on chromosomes 4B, 1A, 1B, 2A and 7B. QBt.ifa-6DL mapped to a region overlapping with the Bt9-locus identified in previous studies, but results indicate that QBt.ifa-6DL is different from Bt9 and convincing evidence from haplotype comparisons suggests that it represents the Bt11 resistance allele. Markers for the distal region of chromosome 6D between 492.6 and 495.2 Mbp can be used to select for QBt.ifa-6DL. This resistance factor confers high and stable resistance against common bunt and should be integrated into organic and low-input wheat breeding programs.
在通过与携带 Bt11 的 PI 166910 和 M822123 的杂交产生的四个作图群体中，鉴定到了与抗条锈病基因 Bt11 对应的位于 6DL 染色体上的一个主要 QTL。自 20 世纪 80 年代开始的有机农业的兴起，使得小麦普通腥黑穗病死灰复燃。有机农业中系统杀菌剂的弃用，再加上缺乏抗性品种，导致普通腥黑穗病感染广泛。对于抗性遗传来源的了解仍然很少，目前只有少数已知的抗腥黑穗病因子被用于育种。因此，我们的目标是定位土耳其地方品种 PI 166910 所携带的抗性因子，PI 166910 是 Bt11 抗腥黑穗病差异系的抗性供体。通过在 2、3 或 4 年的时间里用一个或两个当地腥黑穗病群体对 96-132 个重组自交系 (RILs) 的普通腥黑穗病抗性进行表型分析，以及用 25K SNP 阵列进行基因型分析，四个作图群体 (MPs) 被鉴定出位于 6D 染色体的远端指定为 QBt.ifa-6DL 的一个主要抗腥黑穗病基因座。在所有的 MPs 和实验中都鉴定到了这个基因座。在染色体 4B、1A、1B、2A 和 7B 上还检测到了其他有助于抗性的 QTL。QBt.ifa-6DL 定位在以前研究中鉴定到的 Bt9 基因座的重叠区域，但结果表明 QBt.ifa-6DL 与 Bt9 不同，来自单倍型比较的令人信服的证据表明它代表了 Bt11 抗性等位基因。位于染色体 6D 远端的 492.6 到 495.2 Mbp 之间的染色体 6D 标记可用于选择 QBt.ifa-6DL。该抗性因子对普通腥黑穗病具有高而稳定的抗性，应被整合到有机和低投入的小麦育种计划中。
