University of Natural Resources and Life Sciences, Vienna, Department of Agrobiotechnology (IFA-Tulln), Institute of Biotechnology in Plant Production, Konrad-Lorenz-Straße 20, 3430, Tulln, Austria.
Laboratory of Plant Breeding, Department of Agronomy, Faculty of Agriculture, Universitas Gadjah Mada, Yogyakarta, Indonesia.
Theor Appl Genet. 2023 Aug 28;136(9):201. doi: 10.1007/s00122-023-04426-7.
FHB resistance of durum wheat was improved by introgression of Fhb1 and resistance genes from emmer wheat and by selection against adverse alleles of elite durum wheat. Durum wheat is particularly susceptible to Fusarium head blight (FHB) and breeding for resistance is impeded by the low genetic variation within the elite gene pool. To extend the genetic basis for FHB resistance in durum wheat, we analyzed 603 durum wheat lines from crosses of elite durum wheat with resistance donors carrying resistance alleles derived from Triticum aestivum, T. dicoccum and T. dicoccoides. The lines were phenotyped for FHB resistance, anthesis date, and plant height in artificially inoculated disease nurseries over 5 years. A broad variation was found for all traits, while anthesis date and plant height strongly influenced FHB severities. To correct for spurious associations, we adjusted FHB scorings for temperature fluctuations during the anthesis period and included plant height as a covariate in the analysis. This resulted in the detection of seven quantitative trait loci (QTL) affecting FHB severities. The hexaploid wheat-derived Fhb1 QTL was most significant on reducing FHB severities, highlighting its successful introgression into several durum wheat backgrounds. For two QTL on chromosomes 1B and 2B, the resistance alleles originated from the T. dicoccum line Td161 and T. dicoccoides accessions Mt. Hermon#22 and Mt. Gerizim#36, respectively. The other four QTL featured unfavorable alleles derived from elite durum wheat that increased FHB severities, with a particularly negative effect on chromosome 6A that simultaneously affected plant height and anthesis date. Therefore, in addition to pyramiding resistance genes, selecting against adverse alleles present in elite durum wheat could be a promising avenue in breeding FHB-resistant durum wheat.
硬粒小麦的 FHB 抗性通过导入来自普通小麦和粗山羊草的 Fhb1 和抗性基因以及对优良硬粒小麦的不利等位基因进行选择而得到改善。硬粒小麦特别容易感染赤霉病（FHB），并且由于优良基因库中的遗传变异较低，因此对其进行抗性育种受到阻碍。为了扩展硬粒小麦对 FHB 抗性的遗传基础，我们分析了 603 个来自优良硬粒小麦与携带来自普通小麦、二粒小麦和粗山羊草的抗性基因的抗性供体杂交的硬粒小麦品系。这些系在人工接种疾病苗圃中进行了 5 年的 FHB 抗性、开花期和株高表型分析。所有性状均表现出广泛的变异，而开花期和株高强烈影响 FHB 严重程度。为了纠正虚假关联，我们根据开花期期间的温度波动调整了 FHB 评分，并在分析中包含了株高作为协变量。这导致检测到影响 FHB 严重程度的七个数量性状位点（QTL）。六倍体小麦衍生的 Fhb1 QTL 对降低 FHB 严重程度最为显著，突出了其在几个硬粒小麦背景中的成功导入。对于染色体 1B 和 2B 上的两个 QTL，抗性等位基因分别来自二粒小麦品系 Td161 和粗山羊草的 Mt. Hermon#22 和 Mt. Gerizim#36。其他四个 QTL 具有来自优良硬粒小麦的不利等位基因，这些等位基因增加了 FHB 严重程度，对同时影响株高和开花期的染色体 6A 具有特别负面的影响。因此，除了聚合抗性基因外，选择优良硬粒小麦中存在的不利等位基因可能是培育 FHB 抗性硬粒小麦的有前途的途径。
