Molecular Detection of Disease Resistance Genes in Wheat Varieties Approved in Jiangsu Province

Wheat is a crucial food crop in China, and its production security is closely tied to national food security. Jiangsu Province, a major wheat-producing region in eastern China, frequently suffers from diseases outbreaks due to its humid climate. Fusarium head blight (FHB), Stripe rust, and Powdery mildew are the primary diseases causing severe yield losses and quality degradation. Breeding and deploying multi-resistant varieties are the most economical and effective strategy for disease control. This study aimed to evaluate the comprehensive resistance of wheat varieties approved in Jiangsu over the past decade to these three diseases and to clarify the distribution and pyramiding of corresponding resistance genes using molecular markers, thereby providing a scientific basis and elite parental materials for disease resistance breeding in the region.

Based on the approval data of 185 wheat varieties released in Jiangsu from 2014 to 2023, statistical analyses were conducted on their resistance levels to FHB, Stripe rust, and Powdery mildew. Varieties exhibiting resistance to at least two of these diseases were identified as “multi-resistant”. From 49 multi-resistant varieties, 44 germplasm accessions were selected for molecular detection. Specific markers were used to detect the FHB resistance gene Fhb1, the Powdery mildew resistance gene Pm21, and the Stripe rust resistance genes Yr5, Yr9, Yr15, Yr17, Yr18, Yr26, and Yr30. Experimental procedures included genomic DNA extraction using the CTAB method, optimized PCR systems and protocols, and the inclusion of known positive controls to ensure detection accuracy.

According to the approval data, 53.52%, 43.92%, and 9.72% of the tested varieties showed resistance to Fusarium head blight, Stripe rust, and Powdery mildew, respectively. Five varieties (Ninghongmai 618, Yanmai 1902, Zhongyanmai 238, Yanmai 1903, and Ningmaizi 166) demonstrated resistance to all three diseases, and 49 varieties were resistant to at least two. Molecular marker detection indicated that all 44 multi-resistant accessions carried multiple resistance genes. Pm21, Yr5, Yr17, Yr18, and Yr26 were detected in all materials. Fhb1 was present in 84.1% of accessions, Yr15 in 93.2%, and Yr30 in 88.6%, while Yr9 was found in only three accessions. Notably, the varieties Xumai DH9 and Xumai 100 carried all nine tested resistance genes, demonstrating outstanding genetic potential for disease resistance and highlighting their suitability as ideal parental lines for multi-resistance breeding.

This study confirmed that the approved wheat varieties in Jiangsu Province have rich and unique gene resources for disease resistance through systematic molecular detection. It shows that the wheat varieties approved in Jiangsu province have high breeding and utilization potential. Their potential disease-resistant gene pool has not been fully developed. Based on this study, the screened wheat varieties can serve as a reserve germplasm bank, providing strong genetic support for future multi-resistance breeding in Jiangsu and East China, and alleviating the current challenge of limited sources of disease-resistant varieties.