Genetic mapping and candidate gene analysis for melon resistance to Phytophthora capsici

• Published in: Scientific reports Vol. 10; no. 1; p. 20456
• Main Authors: Wang, Pingyong, Xu, Xiaojun, Zhao, Guangwei, He, Yuhua, Hou, Chong, Kong, Weihu, Zhang, Jian, Liu, Shuimiao, Xu, Yongyang, Xu, Zhihong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24-11-2020; Nature Publishing Group; Nature Portfolio
• Subjects: 631/208; 631/208/2491; 631/208/711; 631/208/8; 631/449; Blight; Chromosome 12; Chromosome Walking - methods; Cucurbitaceae - genetics; Cucurbitaceae - growth & development; Cucurbitaceae - parasitology; Disease Resistance; Fruits; Gene Expression Regulation, Plant; Gene mapping; Genetic analysis; Genetic Linkage; Genetic Markers; Genetics; Humanities and Social Sciences; Inoculation; Kinases; Marker-assisted selection; Models, Molecular; multidisciplinary; Mutation; Phytophthora - pathogenicity; Phytophthora capsici; Plant Breeding; Plant Diseases - parasitology; Plant Proteins - chemistry; Plant Proteins - genetics; Protein Structure, Tertiary; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-77600-2

Phytophthora
blight is one of the most serious diseases affecting melon (
Cucumis melo
) production. Due to the lack of highly resistant germplasms, the progress on disease-resistant research is slow. To understand the genetics of melon resistance to
Phytophthora capsici
, an F
2
population containing 498 individuals was developed by crossing susceptible line E31 to highly resistant line ZQK9. Genetic analysis indicated that the resistance in ZQK9 was controlled by a dominant gene, tentatively named
MePhyto
. Through bulked-segregant analysis (BSA-Seq) and chromosome walking techniques, the
MePhyto
gene was mapped to a 52.44 kb interval on chromosome 12. In this region, there were eight genes and their expression patterns were validated by qRT-PCR. Among them, one wall-associated receptor kinase (WAK) gene
MELO3C002430
was significantly induced in ZQK9 after
P. capsici
inoculation, but not in E31. Based on the non-synonymous mutation site in
MELO3C002430
, a cleaved amplified polymorphic sequence (CAPS) marker, CAPS2430, was developed and this maker was co-segregated with
MePhyto
in both F
2
population and a collection of 36 melon accessions. Thus
MELO3C002430
was considered as the candidate gene and CAPS2430 was a promising marker for marker-assisted selection (MAS) in breeding. These results lay a foundation for revealing the resistance mechanism of melon to
P. capsici
.