Construction of High-Density Genetic Map and Identification of QTLs Associated with Seed Vigor after Exposure to Artificial Aging Conditions in Sweet Corn Using SLAF-seq.

Xiaming Wu,Yu Liu,Jun Huang,Jie Gong,Fugui Xie,Xiaoqin Li,Faqiang Feng,Wei Zhu,Tianle Gao,Danyi Chen,Jing Yang,Yuzhong Zhu

doi:10.3390/genes11010037

Abstract

Seed vigor is a key factor that determines the quality of seeds, which is of great significance for agricultural production, with the potential to promote growth and productivity. However, the underlying molecular mechanisms and genetic basis for seed vigor remain unknown. High-density genetic linkage mapping is an effective method for genomic study and quantitative trait loci (QTL) mapping. In this study, a high-density genetic map was constructed from a 148 BC4F3 population cross between ‘M03’ and ‘M08’ strains based on specific-locus amplified fragment (SLAF) sequencing. The constructed high-density genetic linkage map (HDGM) included 3876 SNP markers on ten chromosomes covering 2413.25 cM in length, with a mean distance between markers of 0.62 cM. QTL analysis was performed on four sweet corn germination traits that are related to seed vigor under artificial aging conditions. A total of 18 QTLs were identified in two seasons. Interestingly, a stable QTL was detected in two seasons on chromosome 10—termed qGR10—within an interval of 1.37 Mb. Within this interval, combined with gene annotation, we found four candidate genes (GRMZM2G074309, GRMZM2G117319, GRMZM2G465812, and GRMZM2G343519) which may be related to seed vigor after artificial aging.

Highlights

Sweet corn (Zea mays L. saccharata Sturt) is a maize-derived vegetable crop with one or more recessive endosperm mutations that reduce the synthesis of starch and increase the accumulation of sugars or other short chain polysaccharides
Higher seed vigor provides greater resistance to various adversities. It is helpful for the long-term preservation of the germplasm resource. It is of great significance in the production of seeds to understand the relationship between seed aging and seed vigor
A BC4 F3 population was created and a high-density genetic linkage map constructed with a mean genetic distance of 0.62 cM between adjacent markers using specific-locus amplified fragment (SLAF)

Summary

Introduction

Sweet corn (Zea mays L. saccharata Sturt) is a maize-derived vegetable crop with one or more recessive endosperm mutations that reduce the synthesis of starch and increase the accumulation of sugars or other short chain polysaccharides. The land area planted with sweet corn in China has expanded rapidly. The total area was approximately 323,000 hm in 2012. It has become an important superior and efficient economic crop in the southern regions of China such as Guangdong, Guangxi, Zhejiang, Yunnan, etc. The demand for sweet corn which has gradually become an indispensable green health food has increased as improvements in quality of life have been achieved. The low germination rate and uneven emergence of seedlings from sweet corn seeds in fields

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