Breeding for Disease Resistance in Brassica Vegetables Using DNA Marker Selection

Abstract

The Brassica genus comprises of agro-economically important vegetables. Disease causes great yield loss of Brassica vegetables worldwide. Different traditional methods such as crop rotation and chemical control have limited effect on different diseases of Brassica vegetables and cannot completely eradicate the pathogens by these methods. Development of disease resistant cultivars is one of the most effective, ecofriendly, and cheapest measure to control Brassica diseases. With the development of genomics, molecular biology techniques, and biological methods, it is possible to discover and introduce resistance (R) genes to efficiently control the plant diseases caused by pathogens. Some R genes of major diseases such as Fusarium wilt and clubroot in Brassica vegetables have been already identified. Therefore, we will focus to review the Fusarium wilt and clubroot resistance in Brassica vegetables and the methodologies for identification, mapping, and pyramiding of R genes/quantitative trait loci (QTLs) to develop disease resistant cultivars. These techniques will be helpful for sustainable crop production and to maintain global food security and contribute to ensure protection of food supply in the Asian country as well as throughout the world.

Development of a New DNA Marker for Fusarium Yellows Resistance in Brassica rapa Vegetables

“…Previously, we identified a resistance gene to Foc (FocBr1), which is a single dominant gene. In susceptible lines, a 35 kb deletion, which includes FocBr1, was found [12], and the susceptible allele was termed focbr1-1 [14]. A dominant DNA marker (Bra012688m) has been made and the prediction of Foc resistance using Bra012688m was consistent with phenotypes of Foc resistance confirmed by an inoculation test in inbred lines of Chinese cabbage [12,15].…”

“…Three lines may be heterozygous for FocBr1 and focbr1-1. In the case of focbr1-1, it is desirable to develop a DNA marker to distinguish between FocBr1/focbr1-1 heterozygosity and FocBr1/FocBr1 homozygosity, i.e., using a linked marker close to the 35-kb deletion [14]. In the case of focbr1-2, codominant DNA marker, focbr1-2m, can distinguish the heterozygosity of FocBr1 and focbr1-2 alleles, which will be useful for breeding stable Fusarium yellows resistant cultivars.…”

“…We have shown that FocBr1 (Bra012688) is a resistance gene to F. oxysporum f. sp. conglutinans (Foc), and deletion of this gene results in susceptibility to Foc [12]; this susceptible allele is termed focbr1-1 [14]. We made a DNA marker (Bra012688m) to detect the deletion of FocBr1 that is homozygous for the focbr1-1 allele [12,15].…”

“…The Fusarium yellows R gene against Foc has been identified in B. rapa (FocBr1) and B. oleracea (FocBo1) [11][12][13][14]. FocBr1 and FocBo1 are orthologs and encode a TIR-NBS-LRR protein.…”

Transcriptional Association between mRNAs and Their Paired Natural Antisense Transcripts Following Fusarium oxysporum Inoculation in Brassica rapa L.

“…conglutinans (Foc) or F. oxysporum f. sp. rapae (For), in B. rapa vegetables, and infection leads to yellowing, wilting, defoliation, stunting, and plant death [3][4][5][6]. A Fusarium yellows resistance gene has been identified in B. rapa [6,7], and a system for DNA marker selection of Fusarium yellows resistance has also been developed [5,6,8].…”