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ARS Home » Pacific West Area » Aberdeen, Idaho » Small Grains and Potato Germplasm Research » Research » Publications at this Location » Publication #415690
Research Project: Enhancing Barley and Oat Productivity, Quality, and Stress Resistance

Location: Small Grains and Potato Germplasm Research

Title: The identification of the peanut wild relative Arachis stenosperma as a source of resistance to stem rot and analyses of genomic regions conferring disease resistance through QTL mapping

Author
item TSAI, YUN-CHING - University Of Georgia
item BRENNEMAN, TIMOTHY - University Of Georgia
item Gao, Dongying
item CHU, YE - University Of Georgia
item LAMON, SAMUELE - University Of Georgia
item BERTIOLI, DAVID - University Of Georgia
item LEAL-BERTIOLI, SORAYA - University Of Georgia

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2024
Publication Date: 7/2/2024
Citation: Tsai, Y., Brenneman, T.B., Gao, D., Chu, Y., Lamon, S., Bertioli, D.J., Leal-Bertioli, S.C. 2024. The identification of the peanut wild relative Arachis stenosperma as a source of resistance to stem rot and analyses of genomic regions conferring disease resistance through QTL mapping. Agronomy. 14(7). https://doi.org/10.3390/agronomy14071442.
DOI: https://doi.org/10.3390/agronomy14071442

Interpretive Summary: White mold is one of the most serious diseases in peanut and other crops. Development of disease resistant cultivars is an effective strategy to control this disease. However, no good resistance resource has been identified in cultivated peanut materials; thus, it is extremely difficult to manage peanut white mold. Previously, a wild peanut germplasm was developed which showed good resistance to multiple major peanut diseases including rust and leafspots. In this study, greenhouse and field evaluations were conducted and it was discovered that the newly developed wild peanut also showed superior resistance to white mold compared to other wild genotypes. To better use the germplasm for peanut breeding, molecular mapping was performed and genetic regions related to white mold resistance were revealed. This work contributes a new resistance source which can be used to reduce the yield losses in peanut caused by white mold.

Technical Abstract: Peanut stem rot, also known as white mold, poses a significant threat to U.S. peanut, typically managed with chemicals and moderately resistant cultivars. Resistant cultivars are required to reduce fungicide dependency and increase crop’s sustainability. This study explores the potential of wild peanut species in stem rot resistance breeding programs by enhancing genetic diversity in cultivated peanut. Through greenhouse and field evaluations, allotetraploids with Arachis stenosperma in their pedigree showed comparatively superior resistance than other wild genotypes. The genomic regions that confer the stem rot resistance were further identified by genotyping and phenotyping an F2 population derived from the allotetraploid ValSten1 (A. valida x A. stenosperma)4x and A. hypogaea cv. TifGP-2. A linkage map was constructed from 1,936 SNP markers. QTL analysis revealed both beneficial and deleterious loci, with two resistance-associated QTLs derived from A. stenosperma and deleterious QTLs from A. valida. Overall, A. stenosperma, the progenitor of ValSten1, offers a resource for stem rot resistance breeding. Markers associated with resistance QTLs can facilitate introgression from ValSten1 into cultivated peanut varieties in future breeding efforts, potentially reducing reliance on chemical control measures.