Anthracnose and bean common mosaic necrosis virus resistance in wild and landrace Phaseolus vulgaris (L.) genetic stocks

Authors: AWALE, HALIMA - Michigan State University; WIERSMA, ANDREW - Archer Daniels Midland; WRIGHT, EVAN - Michigan State University; BUELL, ROBIN - University Of Georgia; KELLY, JAMES - Michigan State University; Cichy, Karen; HAUS, MIRANDA - Michigan State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2024
Publication Date: 5/19/2024
Citation: Awale, H., Wiersma, A., Wright, E., Buell, R.C., Kelly, J., Cichy, K.A., Haus, M. 2024. Anthracnose and bean common mosaic necrosis virus resistance in wild and landrace Phaseolus vulgaris (L.) genetic stocks. Crop Science. https://doi.org/10.1002/csc2.21252.
DOI: https://doi.org/10.1002/csc2.21252

Interpretive Summary: Anthracnose and bean common mosaic necrosis virus (BCMNV) are two important seed borne diseases of common beans (Phaseolus vulgaris). Breeders currently rely on cultivated bean germplasm as sources of resistance to these two pathogens. However, it is worthwhile to identify potential new sources of resistance that can serve as backups for situations where new pathogen races emerge and currently used resistant sources are overcome. Wild common beans may possess novel sources of resistance to these pathogens. The objective of this study was to screen the U. S. National Plant Germplasm System collection of wild common bean germplasm for resistance to anthracnose and BCMNV. In total 249 bean lines were used in this study, including 194 wild and 55 landraces. These lines were screened in a greenhouse assay for resistance to two highly virulent races of Anthracnose and to the BCMNV strain NL-3. Thirteen wild bean lines were found that were resistant to both races of Anthracnose races. No resistance to BCMNV was detected in the wild germplasm and three landraces showed resistance. Future research will determine if any of these are novel sources of resistance worthy to be integrated into bean breeding programs.

Technical Abstract: Wild crop germplasm and landrace varieties have long been considered as a source of novel genetic variation for improving domesticated crops. Due to genetic bottlenecks that occurred during domestication, dissemination, and subsequent crop improvement, many beneficial genes are absent from commercial varieties and elite breeding germplasm, yet are still present in wild populations. To catalog potential novel disease resistance genes useful for breeding more resilient dry beans, we screened wild and landrace Phaseolus vulgaris L. accessions archived in the USDA-GRIN seed bank for untapped resistance to Anthracnose (Colletotrichum lindemuthianum) and bean common mosaic necrosis virus (BCMNV). A population of 194 wild and 55 landrace accessions were screened for resistance to two highly virulent races of Anthracnose (Race 2047 and Race 3481) and for resistance to the BCMNV strain NL-3. Thirteen accessions were resistant to both Anthracnose races with MX-QT-3 and PI 661812 displaying complete resistance with no disease symptoms across all replications. Surprisingly, no natural resistance to BCMNV strain NL-3 was detected in the wild germplasm. PI 442541, PI 661891, and W610164 were the only three accessions that expressed the I-gene phenotype and all three have some history of cultivation. This study provides a resource for introgression of genetic diversity for anthracnose resistance into cultivated beans and reveals that innate resistance to BCMNV may not exist in wild populations of P. vulgaris.