Yali Yan , Min He , Mengxiao He , Xiaohua Qi , Qiang Xu , Xuewen Xu , Xuehao Chen

School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, 225009, China
Author    Correspondence author
Molecular Plant Breeding, 2022, Vol. 13, No. 5   doi: 10.5376/mpb.2022.13.0005
Received: 06 Jan., 2022    Accepted: 20 Jan., 2022    Published: 11 Feb., 2022

This article was first published in Molecular Plant Breeding in Chinese, and here was authorized to translate and publish the paper in English under the terms of Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Yan Y.L., He M., He M.X., Qi X.H., Xu Q., Xu X.W., and Chen X.H., 2022, Genetic analysis and QTL mapping of parthenocarpy in Cucumis sativus L., Molecular Plant Breeding, 13(5): 1-8 (doi: 10.5376/mpb.2022.13.0005)

Breeding of cucumber cultivars with high parthenocarpy rate are the prerequisite that ensuring yield and quality under undesirable environment. The mixed major gene plus polygene inheritance model was used to analyze cucumber parthenocarpy trait in the six generations, including P₁, P₂, F₁, BC₁, BC₂ and F₂, derived from a cross between the highly parthenocarpic line DDX and low parthenocarpic line ZK. The major-effect quantitative trait locus (QTL) was identified by genome-wide comparison of single nucleotide polymorphisms (SNPs) between high- and low- parthenocarpy rate F₂ pools, and confirmed by traditional QTL mapping with genetic map. Genetic analysis showed that the genetic model E-2, mixed two additive-dominant-epistatic major genes and additive-dominant polygenes, is the best-fitting genetic model for cucumber parthenocarpy phenotype. A major-effect QTL, namely par2.1, were identified by the method of Δ(SNP_index). par2.1 was confirmed by traditional markers based QTL mapping method with least likelihood (LOD) peak score of 12.6, genetic distance of 11.5cM and accounting for 26.6% of the total phenotypic variance. par2.1 was narrowed down to a 765kb region through comparison of markers physical locations on chromosome 2. The major-effect QTL, par2.1 on Chr2, for parthenocarpy identified by this study was not reported previously. Our findings shed light on the genetic architecture underlying cucumber parthenocarpy trait, and lay a solid basis for innovation of cucumber parthenocarpy germplasm and breed of new cucumber varieties with high parthenocarpy.

Cucumber (Cucumis sativus L.); Parthenocarpy; Genetic analysis; QTL; par2.1