Marker-Assisted Pyramiding of Genes for Multilocular Ovaries, Self-Compatibility, and Clubroot Resistance in Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

Jingyi Zheng,Mingliang Jiang,Zhongyun Piao,Zongxiang Zhan,Huicai Zhao,Yingmei Ma,Xiaonan Li

doi:10.3390/horticulturae8020139

Jingyi Zheng, Mingliang Jiang + Show 5 more

Open Access

https://doi.org/10.3390/horticulturae8020139

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Abstract

Molecular marker-assisted gene pyramiding combined with backcrossing has been widely applied for crop variety improvement. Molecular marker identification could be used in the early stage of breeding to achieve the rapid and effective pyramiding of multiple genes. To create high-quality germplasm for Chinese cabbage breeding, multi-gene pyramiding for self-compatibility, multilocular, and clubroot resistance was performed through molecular marker-assisted selection. The results showed that self-compatibility and multilocular traits were controlled by a pair of recessive genes. Two flanking markers, sau_um190 and cun_246a, and marker Teo-1, based on the gene sequence related to multilocular ovaries, were used for multilocular ovary trait selection. Two flanking markers, SCF-6 and SC-12, and marker Sal-SLGI /PK1+PK4, based on the gene sequence, were used for self-compatibility selection. Two flanking markers, TCR74 and TCR79, closely linked to clubroot resistance gene CRb, were used as foreground selection markers. Based on Chinese cabbage genomic information, 111 SSR markers covering 10 chromosomes were applied for background selection. After multiple generations of selection, a multi-gene pyramided line from a BC4F2 population with self-compatibility, multilocular ovaries, and clubroot resistance was obtained with a high genomic background recovery rate. The improved pyramided line is expected to be utilized as a potential material in further breeding programs.

Highlights

Chinese cabbage (Brassica rapa L. ssp. pekinensis), belonging to the Brassica subspecies of the Brassicaceae family, is widely cultivated in China, Korea, and Japan
Among eight pairs of marker combinations designed for self-compatibility, as shown in Table S2, PCR bands were amplified only in KYS using PK1+PK4 and in CR BJN3-2 using Sal-SRKI and Sal-SLGI
The large number of gene/QTL mapping studies for diverse crops has provided an abundance of molecular markers associated with traits [48]

Summary

Introduction

Chinese cabbage (Brassica rapa L. ssp. pekinensis), belonging to the Brassica subspecies of the Brassicaceae family, is widely cultivated in China, Korea, and Japan. Pekinensis), belonging to the Brassica subspecies of the Brassicaceae family, is widely cultivated in China, Korea, and Japan. Most of the common commercial cultivars on the market are first-generation hybrids. Owing to self-incompatibility, it is difficult to reproduce the parent lines, and the cost of artificial seed production is high. The seed yield of Chinese cabbage is limited, which is influenced by silique-related traits. Clubroot, as one of the main diseases of cruciferous crops, has severely threatened the production of Chinese cabbage. Breeding clubroot-resistant (CR) varieties is the most effective method for clubroot prevention since physical and biological control methods have limited effects. Cultivar pyramiding with multilocular silique, self-compatibility, and clubroot resistance would be an ideal resource for Chinese cabbage breeding

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