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ARS Home » Pacific West Area » Pullman, Washington » Plant Germplasm Introduction and Testing Research » Research » Publications at this Location » Publication #315873

Research Project: Enhancing Resistance to Diseases and Abiotic Stresses in Alfalfa

Location: Plant Germplasm Introduction and Testing Research

Title: Identification of loci associated with drought resistance traits in heterozygous autotetraploid alfalfa (Medicago sativa L.) using genome-wide association studies with genotyping by sequencing

Author
item ZHANG, TIEJUN - Chinese Academy Of Agricultural Sciences
item Yu, Long-Xi
item ZHENG, PING - Washington State University
item LI, YAJUN - Chinese Academy Of Agricultural Sciences
item Rivera, Martha
item MAIN, DORRIE - Washington State University
item Greene, Stephanie

Submitted to: PLoS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/10/2015
Publication Date: 9/25/2015
Citation: Zhang, T., Yu, L., Zheng, P., Li, Y., Rivera, M.C., Main, D., Greene, S.L. 2015. Identification of loci associated with drought resistance traits in heterozygous autotetraploid alfalfa (Medicago sativa L.) using genome-wide association studies with genotyping by sequencing. PLoS One. 1-17. https://doi.org/10.1371/journal.pone.0138931.
DOI: https://doi.org/10.1371/journal.pone.0138931

Interpretive Summary: Drought resistance is an important breeding target for enhancing alfalfa productivity in arid and semi-arid regions. Developing molecular markers associated with drought resistance would be helpful for improving the accuracy in selecting resistant alfalfa, and accelerating the breeding process. We used a panel of accessions comprised of 200 alfalfa cultivars and landraces with potential drought tolerance in the present study. A greenhouse procedure was used for evaluating drought resistance index (DRI) and relative leaf water content (RWC). Marker-trait association identified fourteen and nine molecular for DRI and RWC, respectively. With further validation, these markers can be used for marker-assisted selection for breeding new alfalfa varieties with drought resistance and enhanced water use efficiency.

Technical Abstract: Developing molecular markers associated with drought resistance would be helpful for improving the accuracy in selecting resistant alfalfa, and accelerating the breeding process. A panel of accessions comprised of 200 alfalfa cultivars and landraces with potential drought tolerance were selected from the USDA-ARS National Plant Germplasm System alfalfa collection (http://www.ars-grin/npgs.gov) and genotyped using genotyping by sequencing. A greenhouse procedure was used for evaluating drought resistance index (DRI) and relative leaf water content (RWC). Marker-trait association was analyzed using linkage disequilibrium. Fourteen and nine single nucleotide polymorphism (SNP) markers were identified for DRI and RWC, respectively. Alignments of target sequences of the significant SNPs to the reference genome of M. truncatula revealed multiple chromosomal locations. Markers associated with DRI are located on chromosomes 2, 4, 5, 6 and 7, while markers associated with RWC are located on chromosomes 1, 2, 3, 4 and 5. Overlap of significant markers between DRI and RWC were found on chromosomes 2, 4 and 5. Additional significant markers were targeted to several contigs with unknown chromosomal location. With further validation, these markers can be used for marker-assisted selection for breeding new alfalfa varieties with drought resistance and enhanced water use efficiency.