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

Abstract

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 F2 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 F2 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.

Genome assembly and analysis of Lactuca virosa: implications for lettuce breeding

“…For example, G-LecRK and WAK can both mediate resistance to Phytophthora spp. (oomycete) in tobacco and melon plants ( Wang et al 2020 ; Pi et al 2022 ). On the contrary, the expansion of Malectin-RK might benefit pathogen invasion in L. sativa , like the increased susceptibility to Hyaloperonospora arabidopsidis (oomycete) observed in Arabidopsis ( Hok et al 2011 ).…”

The Melon Zym Locus Conferring Resistance to ZYMV: High Resolution Mapping and Candidate Gene Identification

“…The development of full genomic and transcriptomic sequences and new mapping approaches, such as genotyping by sequencing (GBS), and availability of core collections and Introgression Lines, produced a plethora of mapping studies (e.g., [14,15] and references therein). For example, Wang et al [16] mapped at high resolution downy mildew resistance in melon and identified a likely candidate, a receptor kinase gene; Giner et al [17] mapped CMV resistance, and we have finely mapped PRSV and Fusarium resistances [18].…”

Phenotypic analysis of Longya-10 × pale flax hybrid progeny and identification of candidate genes regulating prostrate/erect growth in flax plants

“…Bulked segregant analysis sequencing (BSA-Seq) is a rapid and efficient approach that has been developed for the identification of major QTLs or genes associated with a given phenotype ( Michelmore et al., 1991 ; Kurlovs et al., 2019 ). BSA-Seq has been successfully used for mapping agronomically important loci in many plants, such as those associated with the branching habit trait in peanut ( Kayam et al., 2017 ), leafy head formation in Chinese cabbage ( Li R et al., 2019 ), genes controlling cold tolerance, QTLs controlling basal resistance to blast disease in rice ( Guo et al., 2020 ; Liang et al., 2020 ), candidate genes involved in the development of curd riceyness in cauliflower ( Zhao et al., 2020 ), a major QTL for shoot branching in Brassica rapa ( Li et al., 2020 ), and genes related to melon resistance in Phytophthora capsici ( Wang et al., 2020 ). Marker-assisted selection (MAS) is also an economical and efficient method, which has been successfully used in crops ( Chen et al., 2021 ; Zhang et al., 2022 ).…”