In the ongoing battle against stripe rust, a formidable foe of wheat crops worldwide, researchers have made significant strides in unraveling the genetic secrets of resistance. A recent study led by Fangping Yang from the Wheat Research Institute at the Gansu Academy of Agricultural Sciences in China has identified six key genetic regions, or quantitative trait loci (QTL), that contribute to adult-plant resistance (APR) against stripe rust in wheat. This research, published in the journal ‘Plants’ (which translates to ‘Plants’ in English), offers promising avenues for enhancing disease resistance in wheat breeding programs, with potential commercial impacts for the agricultural sector.
Stripe rust, caused by the fungus *Puccinia striiformis* f. sp. *tritici* (Pst), poses a significant threat to wheat production globally. The study focused on the Chinese winter wheat variety Lantian 25, known for its moderate-to-high resistance to stripe rust. By crossing Lantian 25 with the susceptible variety Huixianhong, researchers created 219 recombinant inbred lines (RILs) and evaluated them across four different environments over two growing seasons.
Using advanced genotyping techniques, including the wheat Illumina 50K single-nucleotide polymorphism (SNP) arrays, the team identified six QTL that consistently influenced resistance across multiple environments. These QTL, named *QYr.gaas-2BS*, *QYr.gaas-2BL*, *QYr.gaas-2DS*, *QYr.gaas-2DL*, *QYr.gaas-3BS*, and *QYr.gaas-4BL*, explained between 4.8% and 12.0% of the phenotypic variation in stripe rust resistance.
“Identifying these QTL is a crucial step in understanding the genetic basis of adult-plant resistance to stripe rust,” said Yang. “This knowledge can be leveraged to develop more resilient wheat varieties, which is essential for sustainable agriculture and food security.”
Three of the identified QTL overlapped with previous studies, validating their importance, while the other three—*QYr.gaas-2BS*, *QYr.gaas-2DS*, and *QYr.gaas-4BL*—may represent novel discoveries. All resistance alleles for these QTL were derived from Lantian 25, highlighting its value as a resistance source.
To facilitate practical applications, the researchers developed and validated four kompetitive allele-specific PCR (KASP) markers associated with the identified QTL. These markers, named *Kasp_2BS_YR*, *Kasp_2BL_YR*, *Kasp_2DS_YR*, and *Kasp_2DL_YR*, were tested in 110 diverse wheat accessions, demonstrating their utility for marker-assisted selection in breeding programs.
Additionally, the study identified seven candidate genes linked to stripe rust resistance, including disease resistance protein RGA2, serine/threonine-protein kinase, F-box family proteins, leucine-rich repeat family proteins, and E3 ubiquitin-protein ligases. These findings provide a deeper understanding of the molecular mechanisms underlying resistance and open new avenues for targeted breeding and genetic engineering.
The commercial implications of this research are substantial. By incorporating these QTL and associated markers into breeding programs, wheat breeders can develop varieties with enhanced resistance to stripe rust, reducing the need for chemical controls and improving crop yields. This not only benefits farmers but also contributes to global food security and economic stability in the agricultural sector.
As Yang noted, “The development of resistant varieties is a sustainable solution to stripe rust, which can help mitigate the economic losses associated with this devastating disease.”
This research not only advances our understanding of stripe rust resistance but also sets the stage for future developments in wheat breeding. By harnessing the power of genomics and molecular markers, the agricultural industry can make significant strides in developing crops that are more resilient to diseases, ultimately ensuring a more secure and sustainable food supply.