Volante Andrea, Tondelli Alessandro, Aragona Maria, Valente Maria Teresa, Biselli Chiara, Desiderio Francesca, Bagnaresi Paolo, Matic Slavica, Gullino Maria Lodovica, Infantino Alessandro, Spadaro Davide, Valè Giampiero
Council for Agricultural Research and Economics (CREA), Rice Research Unit, S.S. 11 to Torino, Km 2.5, 13100, Vercelli, Italy.
Council for Agricultural Research and Economics (CREA), Genomics Research Centre, Via S. Protaso, 302, 29017, Piacenza, Fiorenzuola d'Arda, Italy.
Rice (N Y). 2017 Dec;10(1):29. doi: 10.1186/s12284-017-0168-z. Epub 2017 Jun 8.
Bakanae disease, caused by seed-borne Fusarium species, mainly F. fujikuroi, is a rice disease whose importance is considerably increasing in several rice growing countries, leading to incremental production losses.
A germplasm collection of japonica rice was screened for F. fujikuroi resistance, allowing the identification of accessions with high-to-moderate levels of resistance to bakanae. A GWAS approach uncovered two genomic regions highly associated with the observed phenotypic variation for response to bakanae infection on the short arm of chromosome 1 (named as qBK1_628091) and on the long arm of chromosome 4 (named as qBK4_31750955). High levels of phenotypic resistance to bakanae were associated to the cumulated presence of the resistant alleles at the two resistance loci, suggesting that they can provide useful levels of disease protection in resistance breeding. A fine comparison with the genomic positions of qBK1_628091 and qBK4_31750955 with respect to the QTLs for bakanae resistance reported in the literature suggests that the resistant loci here described represent new genomic regions associated to F. fujikuroi resistance. A search for candidate genes with a putative role in bakanae resistance was conducted considering all the annotated genes and F. fujikuroi-related DEGs included in the two genomic regions highlighting several gene functions that could be involved in resistance, thus paving the way to the functional characterization of the resistance loci.
New effective sources for bakanae resistance were identified on rice chromosomes 1 and 4 and tools for resistance breeding are provided.
由种子携带的镰刀菌属物种，主要是藤仓镰刀菌引起的恶苗病，是一种在多个水稻种植国家重要性日益增加的水稻病害，导致产量损失不断增加。
对粳稻种质资源库进行了藤仓镰刀菌抗性筛选，从而鉴定出对恶苗病具有高到中等抗性水平的种质。全基因组关联研究（GWAS）方法揭示了两个与恶苗病感染反应的观察到的表型变异高度相关的基因组区域，一个位于第1染色体短臂上（命名为qBK1_628091），另一个位于第4染色体长臂上（命名为qBK4_31750955）。对恶苗病的高水平表型抗性与两个抗性位点上抗性等位基因的累积存在相关，这表明它们在抗性育种中可以提供有用的病害保护水平。将qBK1_628091和qBK4_31750955的基因组位置与文献中报道的恶苗病抗性数量性状位点（QTL）进行精细比较，表明这里描述的抗性位点代表了与藤仓镰刀菌抗性相关的新基因组区域。考虑到两个基因组区域中所有注释基因和与藤仓镰刀菌相关的差异表达基因（DEG），对在恶苗病抗性中具有假定作用的候选基因进行了搜索，突出了几个可能参与抗性的基因功能，从而为抗性位点的功能表征铺平了道路。
在水稻第1和第4染色体上鉴定出了新的有效的恶苗病抗性来源，并提供了抗性育种工具。
