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ARS Home » Southeast Area » Tifton, Georgia » Crop Genetics and Breeding Research » Research » Publications at this Location » Publication #380415
Research Project: Genetics and Integrated Management of Plant Parasitic Nematodes in Cotton and Peanut

Location: Crop Genetics and Breeding Research

Title: Validation of resistance to root-knot nematode incorporated in peanut from the wild relative Arachis stenosperma

Author
item BALLEN-TABORDA, CAROLINA - University Of Georgia
item CHU, YE - University Of Georgia
item OZIAS-AKINS, PEGGY - University Of Georgia
item Timper, Patricia - Patty
item JACKSON, SCOTT - University Of Georgia
item BERTIOLI, DAVID - University Of Georgia
item LEAL-BERTIOLI, SORAYA - University Of Georgia

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2021
Publication Date: 3/15/2021
Citation: Ballen-Taborda, C., Chu, Y., Ozias-Akins, P., Timper, P., Jackson, S., Bertioli, D., Leal-Bertioli, S. 2021. Validation of resistance to root-knot nematode incorporated in peanut from the wild relative Arachis stenosperma. Agronomy Journal. 1-23. https://doi.org/10.1002/agj2.20654.
DOI: https://doi.org/10.1002/agj2.20654

Interpretive Summary: Root-knot nematode (RKN) is a very destructive pathogen to which most peanut cultivars are highly susceptible. Current peanut cultivars rely on a single locus for RKN resistance incorporated from the wild relative Arachis cardenasii, that could be overcome by the development of aggressive nematode populations. Thus, new sources of resistance are continually needed. A new and strong resistance has been found in the wild relative, A. stenosperma, and validated in hybrid lines where molecular markers were described on chromosomes A02 and A09 and reduced nematode development by up to 98.2%. In order to validate these resistance segments, this study screened for root-knot nematode resistance in lines from a cross between the wild hybrid and domestic peanut (BC2F1) and correlated with molecular genotypes. Here, six BC2F1s showed strong resistance. Within the genomic region on A02 there are resistance-gene clusters, often implicated in pathogen resistance. We have provided genomic refinement of these key resistance markers that can be used to inform breeding via marker selection and insights into the functional basis of resistance provided by the wild peanut relative A. stenosperma.

Technical Abstract: Root-knot nematode (RKN) is a very destructive pathogen to which most peanut cultivars are highly susceptible. Current peanut cultivars rely on a single locus for RKN resistance incorporated from the wild relative Arachis cardenasii, that could be overcome as a result of the emergence of new nematode populations. Thus, new sources of resistance are continually needed. A new and strong resistance has been found in the wild diploid relative, A. stenosperma, and validated in tetraploid lines where QTL were described on chromosomes A02 and A09 and reduced nematode development by up to 98.2%. In order to validate these resistance segments, this study screened for root-knot nematode resistance in BC2F1s lines and correlated with molecular genotypes. Here, six BC2F1s carrying chromosome introgressions in A02 and/or A09, showed strong resistance. Within the genomic region on A02 there are R-gene clusters, often implicated in pathogen resistance. We have provided genomic refinement of these key resistance QTL that can be used to inform breeding via marker selection and insights into the functional basis of resistance provided by the wild peanut relative A. stenosperma.