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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #367113
Research Project: Evaluation and Development of Improved Soybean Germplasm, Curation of USDA Accessions and Regional Evaluations of New Genotypes

Location: Crop Genetics Research

Title: Mapping and confirmation of quantitative trait loci (QTLs) associated with carbon isotope ratio (d13c) in soybean

Author
item BAZZER, SUMANDEEP - University Of Arkansas
item KALER, AVJINDER - University Of Arkansas
item KING, C - University Of Arkansas
item Ray, Jeffery - Jeff
item HWANG, SADAL - University Of Florida
item PURCELL, LARRY - University Of Arkansas

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/3/2020
Publication Date: 8/7/2020
Citation: Bazzer, S.K., Kaler, A.S., King, C.A., Ray, J.D., Hwang, S., Purcell, L.C. 2020. Mapping and confirmation of quantitative trait loci (QTLs) associated with carbon isotope ratio (d13c) in soybean. Crop Science. 60:2479-2499. https://doi.org/10.1002/csc2.20240.
DOI: https://doi.org/10.1002/csc2.20240

Interpretive Summary: Water deficit stress continues to be one of the major factors limiting soybean yield. Soybean genotypes with increased water use efficiency may be used to develop cultivars with increased yield under drought. The objective of this study was to identify DNA regions associated with water use efficiency using a genetically segregating population. Field experiments were conducted in five environments under limited and well-watered conditions and water use efficiency measured. A total of 25 putative regions associated with water use efficiency were identified on seven chromosomes. These regions may be an important resource in improving drought tolerance using marker assisted selection.

Technical Abstract: Insufficient moisture availability often limits soybean (Glycine max (L.) Merr.) yield. Carbon isotope ratio (d13C) provides an integrated measurement of WUE in C3 plants due to its substantial genetic variance, high heritability, and small genotype by environment interaction (G×E). The objective of this study was to identify quantitative trait loci (QTLs) associated with d13C using a recombinant inbred line (RIL) population derived from a cross between KS4895 and Jackson. The field experiment was conducted in five environments to evaluate d13C under drought and well-watered conditions. Analysis of variance of d13C averaged over environment and over irrigation treatment showed significant effects of genotype (G), environment (E), and G × E. Heritability of d13C in different environments and irrigation treatments ranged from 66% to 79%. Averaged over environments and over irrigation treatments heritability was 85%. A total of 25 QTLs associated with d13C were identified, which were clustered in nine genomic regions on seven chromosomes. The QTL clusters on Gm05 (1), Gm06 (2) and Gm20 (1) were detected across different environments and irrigation regimes that collectively accounted for 53% of the phenotypic variation. The QTLs on Gm06 and Gm20 also showed additive × additive epistasis that contributed approximately 4.2% to the total phenotypic variation. Several identified d13C QTLs overlapped with QTLs associated with other physiological traits related to plant water status, biological nitrogen fixation, and plant morphology. Identified genomic regions may be an important resource in improving drought tolerance using marker assisted selection.