Detection of Blackleg Resistance Gene Rlm1 in Double-Low Rapeseed Accessions from Sichuan Province, by Kompetitive Allele-Specific PCR

Abstract

Blackleg is a serious disease in Brassica plants, causing moderate to severe yield losses in rapeseed worldwide. Although China has not suffered from this disease yet (more aggressive Leptosphaeria maculans is not present yet), it is crucial to take provisions in breeding for disease resistance to have excellent blackleg-resistant cultivars already in the fields or in the breeding pipeline. The most efficient strategy for controlling this disease is breeding plants with identified resistance genes. We selected 135 rapeseed accessions in Sichuan, including 30 parental materials and 105 hybrids, and we determined their glucosinolate and erucic acid content and confirmed 17 double-low materials. A recently developed single-nucleotide polymorphism (SNP) marker, SNP_208, was used to genotype allelic Rlm1/rlm1 on chromosome A07, and 87 AvrLm1 -resistant materials. Combined with the above-mentioned seed quality data, we identified 11 AvrLm1 -resistant double-low rapeseed accessions, including nine parental materials and two hybrids. This study lays the foundation of specific R gene-oriented breeding, in the case that the aggressive Leptosphaeria maculans invades and establishes in China in the future and a robust and less labor consuming method to identify resistance in canola germplasm.

Fine mapping PsPS1, a gene controlling pod softness that defines market type in pea (Pisum sativum)

“…The KASP molecular marker that were developed and identified to be tightly linked with PsPS1 , for instance, KaSP‐10–KaSP‐14 , will facilitate early‐stage and precise selection of the target traits through marker‐assisted selection to accelerate the breeding process. Compared with other types of DNA markers such as SSR that are currently used in pea (Singh et al, 2015), KASP represents a new generation marker technology, which can be used to analyse single nucleotide polymorphisms and has the advantages of high accuracy, flexibility and low cost (Bello et al, 2014; Chai et al, 2021; Grewal, Hubbart‐Edwards, et al, 2020; Grewal, Othmeni, et al, 2020). In pea, KASP markers have been used for the study of resistance to Mosaic Virus Pathotype P1 (Swisher Grimm & Porter, 2020), powdery mildew (Ma et al, 2017), ascochyta blight (Jha et al, 2019), and salt tolerance (Javid et al, 2015).…”

Expanding Gene-Editing Potential in Crop Improvement with Pangenomes

“…In wheat, mlo mutant plants also showed an allele-specific level of enhanced susceptibility to powdery mildew disease [79]. Numerous other examples of allele-specific phenotypes were observed to modulate crop disease resistance [59,81,82], abiotic stress tolerance [83], herbicide resistance [84,85], and yield in polyploid crops such as wheat [86] and camelina (Camelina sativa) [87]. In camelina, the selective mutagenesis of the three delta-12-desaturase genes (FAD2) showed reduced levels of polyunsaturated fatty acids and increased accumulation of oleic acid in the oil, corresponding with the different alleles for the three FAD2 loci [87].…”