Two User-Friendly Molecular Markers Developed for the Identification of Hybrid Lethality Genes in Brassica oleracea

Zhiliang Xiao,Yangyong Zhang,Zhiyuan Fang,Fengqing Han,Honghao Lv,Yong Wang,Mu Zhuang,Jialei Ji,Congcong Kong,Zhansheng Li,Limei Yang

doi:10.3390/agronomy11050982

Zhiliang Xiao, Yangyong Zhang + Show 9 more

Open Access

https://doi.org/10.3390/agronomy11050982

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Abstract

Cabbage (Brassica oleracea) is an important vegetable crop that is cultivated worldwide. Previously, we reported the identification of two dominant complementary hybrid lethality (HL) genes in cabbage that could result in the death of hybrids. To avoid such losses in the breeding process, we attempted to develop molecular markers to identify HL lines. Among 54 previous mapping markers closely linked to BoHL1 or BoHL2, only six markers for BoHL2 were available in eight cabbage lines (two BoHL1 lines; three BoHL2 lines; three lines without BoHL); however, they were neither universal nor user-friendly in more inbred lines. To develop more accurate markers, these cabbage lines were resequenced at an ~20× depth to obtain more nucleotide variations in the mapping regions. Then, an InDel in BoHL1 and a single-nucleotide polymorphism (SNP) in BoHL2 were identified, and the corresponding InDel marker MBoHL1 and the competitive allele-specific PCR (KASP) marker KBoHL2 were developed and showed 100% accuracy in eight inbred lines. Moreover, we identified 138 cabbage lines using the two markers, among which one inbred line carried BoHL1 and 11 inbred lines carried BoHL2. All of the lethal line genotypes obtained with the two markers matched the phenotype. Two markers were highly reliable for the rapid identification of HL genes in cabbage.

Highlights

IntroductionCapitata), a cole crop species, is a vegetable of worldwide economic importance due to its strong resistance, wide adaptability, favorable taste and health-related value [1,2]
Among the markers linked to the BoHL1 gene, none of the twenty-nine markers showed 100% accuracy in the eight cabbage lines, and eight markers presented 87.5% accuracy
Among the markers linked to BoHL2, six InDel markers, HL205, HL230, L27, L237, L43 and L411, showed 100% accuracy in distinguishing the eight cabbage lines (Figure 1), and six markers showed 87.5% accuracy (HL202, HL204, HL207, HL208, HL209 and HL235)

Summary

Introduction

Capitata), a cole crop species, is a vegetable of worldwide economic importance due to its strong resistance, wide adaptability, favorable taste and health-related value [1,2]. Compared with traditional varieties, most commercial cabbage cultivars are first-generation hybrids with strong heterosis (hybrid vigor) that are widely used in cabbage production [3,4]. Heterosis is defined as the phenomenon that the progeny of diverse varieties of a species or crosses between species exhibit greater biomass, development speeds, and fertility than both parents. Heterosis is used to improve yield, uniformity, and vigor and is exploited in the breeding of corn, sorghum, rice, sugar beet, onion, spinach, sunflower, broccoli, and hemp, among others [5,6,7,8,9,10]

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