Lee Robert C, Grime Christina R, O'Driscoll Kane, Khentry Yuphin, Farfan-Caceres Lina M, Tahghighi Hediyeh, Kamphuis Lars G
Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, 6102 Australia.
Phytopathology. 2023 Feb;113(2):265-276. doi: 10.1094/PHYTO-02-22-0051-R. Epub 2023 Feb 8.
Ascochyta blight is a damaging disease that affects the stems, leaves, and pods of field pea () and impacts yield and grain quality. In Australia, field pea Ascochyta blight is primarily caused by the necrotrophic fungal species and . In this study, we screened 1,276 spp. germplasm accessions in seedling disease assays with a mix of three isolates of and 641 accessions with three mixed isolates of (513 accessions were screened with both species). A selection of three accessions with low disease scores for either pathogen, or in some cases both, were crossed with Australian field pea varieties PBA Gunyah and PBA Oura, and recombinant inbred line populations were made. Populations at the F and F generation were phenotyped for their disease response to and , and genotypes were determined using the diversity arrays technology genotyping method. Marker-trait associations were identified using a genome-wide association study approach. Trait-associated loci were mapped to the published genome assembly, and candidate resistance gene analogues were identified in the corresponding genomic regions. One locus on chromosome 2 (LG1) was associated with resistance to , and the 8 Mb genomic region contains 156 genes, two of which are serine/threonine protein kinases, putatively contributing to the resistance trait. A second locus on chromosome 5 (LG3) was associated with resistance to , and the 35 Mb region contains 488 genes, of which five are potential candidate resistance genes, including protein kinases, a mitogen-activated protein kinase, and an ethylene-responsive protein kinase homolog.
壳二孢叶枯病是一种具有破坏性的病害，会影响豌豆（Pisum sativum）的茎、叶和豆荚，进而影响产量和籽粒品质。在澳大利亚，豌豆壳二孢叶枯病主要由坏死营养型真菌物种Ascochyta pinodes和Ascochyta pisi引起。在本研究中，我们在幼苗病害试验中，用三种Ascochyta pinodes分离株的混合物对1276份Pisum spp.种质资源进行了筛选，并用三种Ascochyta pisi混合分离株对641份种质资源进行了筛选（513份种质资源用两种真菌进行了筛选）。选择了三种对任一病原菌，或在某些情况下对两种病原菌病害评分都低的Pisum种质资源，与澳大利亚豌豆品种PBA Gunyah和PBA Oura杂交，并构建了重组自交系群体。对F2和F3代群体针对Ascochyta pinodes和Ascochyta pisi的病害反应进行了表型分析，并使用多样性阵列技术基因分型方法确定了基因型。采用全基因组关联研究方法鉴定标记-性状关联。将性状相关位点定位到已发表的Pisum基因组组装序列上，并在相应的基因组区域中鉴定出候选抗性基因类似物。2号染色体（LG1）上的一个位点与对Ascochyta pinodes的抗性相关，该8 Mb的基因组区域包含156个基因，其中两个是丝氨酸/苏氨酸蛋白激酶，可能对抗性性状有贡献。5号染色体（LG3）上第二个位点与对Ascochyta pisi的抗性相关，该35 Mb区域包含488个基因，其中五个是潜在的候选抗性基因，包括蛋白激酶、一个丝裂原活化蛋白激酶和一个乙烯反应蛋白激酶同源物。
