Genetic Loci Associated with Resistance to Zucchini Yellow Mosaic Virus in Squash

Plants

Vincent Njung’e Michael¹  Swati Shrestha¹  Geoffrey Meru¹  Yuqing Fu¹ 

[1] Horticultural Sciences Department, Tropical Research and Education Center, University of Florida, Homestead, FL 33031, USA;

关键词: QTL-seq;    breeding;    disease resistance;    potyviruses;    quantitative trait loci;    marker-assisted selection;   

DOI  :  10.3390/plants10091935

来源: DOAJ

【 摘 要 】

Zucchini Yellow Mosaic Virus (ZYMV) is an aphid-transmitted potyvirus that causes severe yield losses in squash (Cucurbita moschata) production worldwide. Development of resistant cultivars using traditional breeding approaches relies on rigorous and resource-intensive phenotypic assays. QTL-seq, a whole genome re-sequencing based bulked segregant analysis, is a powerful tool for mapping quantitative trait loci (QTL) in crop plants. In the current study, the QTL-seq approach was used to identify genetic loci associated with ZYMV resistance in an F₂ population (n = 174) derived from a cross between Nigerian Local (resistant) and Butterbush (susceptible). Whole genome re-sequencing of the parents and bulks of resistant and susceptible F₂ progeny revealed a mapping rate between 94.04% and 98.76%, and a final effective mapping depth ranging from 81.77 to 101.73 across samples. QTL-seq analysis identified four QTLs significantly (p < 0.05) associated with ZYMV resistance on chromosome 2 (QtlZYMV-C02), 4 (QtlZYMV-C04), 8 (QtlZYMV-C08) and 20 (QtlZYMV-C20). Seven markers within the QTL intervals were tested for association with ZYMV resistance in the entire F₂ population. For QtlZYMV-C08, one single nucleotide polymorphism (SNP) marker (KASP-6) was found to be significantly (p < 0.05) associated with ZYMV resistance, while two SNPs (KASP-1 and KASP-3) and an indel (Indel-2) marker were linked to resistance within QtlZYMV-C20. KASP-3 and KASP-6 are non-synonymous SNPs leading to amino acid substitutions in candidate disease resistant gene homologs on chromosomes 20 (CmoCh20G003040.1) and 8 (CmoCh08G007140.1), respectively. Identification of QTL and SNP markers associated with ZYMV resistance will facilitate marker-assisted selection for ZYMV resistance in squash.

【 授权许可】

Unknown