Genomic-Assisted Marker Development Suitable for CsCvy-1 Selection in Cucumber Breeding.

Erdem Kahveci,Mahmut Tör,David J Studholme,Yiguo Hong,Zübeyir Devran,Ercan Özkaynak

doi:10.3389/fpls.2021.691576

Abstract

Cucumber is a widely grown vegetable crop plant and a host to many different plant pathogens. Cucumber vein yellowing virus (CVYV) causes economic losses on cucumber crops in Mediterranean countries and in some part of India such as West Bengal and in African countries such as Sudan. CVYV is an RNA potyvirus transmitted mechanically and by whitefly (Bemisia tabaci) in a semipersistent manner. Control of this virus is heavily dependent on the management of the insect vector and breeding virus-resistant lines. DNA markers have been used widely in conventional plant breeding programs via marker-assisted selection (MAS). However, very few resistance sources against CVYV in cucumber exist, and also the lack of tightly linked molecular markers to these sources restricts the rapid generation of resistant lines. In this work, we used genomics coupled with the bulked segregant analysis method and generated the MAS-friendly Kompetitive allele specific PCR (KASP) markers suitable for CsCvy-1 selection in cucumber breeding using a segregating F2 mapping population and commercial plant lines. Variant analysis was performed to generate single-nucleotide polymorphism (SNP)-based markers for mapping the population and genotyping the commercial lines. We fine-mapped the region by generating new markers down to 101 kb with eight genes. We provided SNP data for this interval, which could be useful for breeding programs and cloning the candidate genes.

Highlights

Cucumber plants, Cucumis sativus, have been cultivated as a vegetable crop across the globe for centuries (Tatlioglu, 1993)
One of the most devastating viral pathogens is Cucumber vein yellowing virus (CVYV), which belongs to the Potyviridae family (Lecoq et al, 2000), has an RNA genome (Janssen et al, 2005), is transmitted mechanically and by whitefly, Bemisia tabaci, in a semipersistent manner (Mansour and Al-Musa, 1993), and infects a number of cucurbit species (Gil-Salas et al, 2011)
A total of 120 F2 lines were taken to F3 level, and 20 F3 lines descending from each F2s were inoculated with the virus to determine accurately the phenotype of the mapping population

Summary

Introduction

Cucumis sativus, have been cultivated as a vegetable crop across the globe for centuries (Tatlioglu, 1993). One of the most devastating viral pathogens is Cucumber vein yellowing virus (CVYV), which belongs to the Potyviridae family (Lecoq et al, 2000), has an RNA genome (Janssen et al, 2005), is transmitted mechanically and by whitefly, Bemisia tabaci, in a semipersistent manner (Mansour and Al-Musa, 1993), and infects a number of cucurbit species (Gil-Salas et al, 2011). The main symptoms of CVYV on the cucumber include vein clearing followed by vein yellowing on the youngest leaves (Cohen and Nitzany, 1960), the occasional occurrence of yellow/green mosaics on the fruit (Cuadrado et al, 2007), and eventual general necrosis of the entire infected plant (Cohen and Nitzany, 1960). Mechanical transmission of the virus allows the use of cucumber as a test and indicative plant for multiplication

Methods

Results

Conclusion