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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #347782
Title: Association mapping identifies loci for canopy temperature under drought in diverse soybean genotypes

Author
item KALER, AVJINDER - University Of Arkansas
item Ray, Jeffery - Jeff
item SCHAPAUGH, WILLIAM - Kansas State University
item ASEBEDO, ANTONIO - Kansas State University
item KING, ANDY - University Of Arkansas
item GBUR, E - University Of Arkansas
item PURCELL, LARRY - University Of Arkansas

Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2018
Publication Date: 7/18/2018
Citation: Kaler, A.S., Ray, J.D., Schapaugh, W.T., Asebedo, A.R., King, A., Gbur, E.E., Purcell, L.C. 2018. Association mapping identifies loci for canopy temperature under drought in diverse soybean genotypes. Euphytica. 214:135. https://doi.org/10.1007/s10681-018-2215-2.
DOI: https://doi.org/10.1007/s10681-018-2215-2

Interpretive Summary: Drought stress is a global constraint for crop production, and improving crop tolerance to drought is of critical importance. Because transpiration cools a crop canopy, a cool canopy under drought indicates a plant still has access to soil moisture. Our objectives were to identify regions in the soybean DNA associated with canopy temperature (CT) and to identify extreme genotypes for CT. A diverse panel of 345 soybean accessions was evaluated in three environments for CT. A set of 31,260 molecular markers were used to identify 34 DNA regions likely associated with CT. Several genes in the DNA regions have functions related to transpiration or water acquisition. Favorable markers may be an important resource for combining different genes. Additionally, several soybean lines were identified as sources of drought-tolerance that could be used in breeding programs for improving drought tolerance.

Technical Abstract: Drought stress is a global constraint for crop production, and improving crop tolerance to drought is of critical importance. Because transpiration cools a crop canopy, a cool canopy under drought indicates a genotype still has access to soil moisture. Our objectives were to identify genomic regions associated with canopy temperature (CT) and to identify extreme genotypes for CT. A diverse panel consisting of 345 maturity group IV soybean accessions was evaluated in three environments for CT. Within each environment CT was normalized (nCT) on a scale from 0 to 1. A set of 31,260 polymorphic SNPs with a minor allele frequency (MAF) = 5% were used for association mapping of nCT. Association mapping identified 52 single nucleotide polymorphisms (SNPs) significantly associated with nCT, and these SNPs likely tagged 34 different genomic regions. Averaged across all environments (AAE), eight genomic regions showed significant associations with nCT. Several genes in the identified genomic regions had reported functions related to transpiration or water acquisition including root development, response to abscisic acid, water deprivation, stomatal complex morphogenesis, and signal transduction. Fifteen of the SNPs associated with nCT were coincident with SNPs for canopy wilting. Favorable alleles from significant SNPs may be an important resource for pyramiding genes, and several genotypes were identified as sources of drought-tolerant alleles that could be used in breeding programs for improving drought tolerance.