Field Pea (Pisum sativum) Germplasm Screening for Seedling Ascochyta Blight Resistance and Genome-Wide Association Studies Reveal Loci Associated with Resistance to Peyronellaea pinodes and Ascochyta koolunga.
Phytopathology
; 113(2): 265-276, 2023 Feb.
Article
en En
| MEDLINE
| ID: mdl-35984372
ABSTRACT
Ascochyta blight is a damaging disease that affects the stems, leaves, and pods of field pea (Pisum sativum) and impacts yield and grain quality. In Australia, field pea Ascochyta blight is primarily caused by the necrotrophic fungal species Peyronellaea pinodes and Ascochyta koolunga. In this study, we screened 1,276 Pisum spp. germplasm accessions in seedling disease assays with a mix of three isolates of P. pinodes and 641 accessions with three mixed isolates of A. koolunga (513 accessions were screened with both species). A selection of three P. sativum 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 F34 and F45 generation were phenotyped for their disease response to P. pinodes and A. koolunga, 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 P. sativum 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 P. pinodes, 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 A. koolunga, 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.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Pisum sativum
/
Estudio de Asociación del Genoma Completo
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
/
Risk_factors_studies
/
Screening_studies
País/Región como asunto:
Oceania
Idioma:
En
Revista:
Phytopathology
Asunto de la revista:
BOTANICA
Año:
2023
Tipo del documento:
Article