Bridging old and new: diversity and evaluation of high iron-associated stress response of rice cultivated in West Africa. (11th April 2020)

• Record Type: Journal Article
• Authors: Diop, Bathe; Wang, Diane R; Drame, Khady N; Gracen, Vernon; Tongoona, Pangirayi; Dzidzienyo, Daniel; Nartey, Eric; Greenberg, Anthony J; Djiba, Saliou; Danquah, Eric Y; McCouch, Susan R
• Editors: Rebetzke, Greg
• Is Part Of: Journal of experimental botany. Volume 71:Number 14(2020)
• Page Start: 4188
• Page End: 4200
• Publication Date: 2020-04-11
• Subjects: Abiotic stress -- genetic diversity -- GWAS -- population structure -- rice -- West Africa; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/eraa182
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : Rice cultivated in West Africa contains useful genetic variation for performance under high iron-associated stress, and knowledge about trait variation for efficient selection criteria can guide applications in breeding. Abstract: Adoption of rice varieties that perform well under high iron-associated (HIA) stress environments can enhance rice production in West Africa. This study reports the genetic characterization of 323 rice accessions and breeding lines cultivated in West Africa using genotyping-by-sequencing and their phenotypic response to HIA treatments in hydroponic solution (1500 mg l −1 FeSO4 ·7H2 O) and hot-spot fields. The germplasm consisted of four genetic subpopulations: Oryza glaberrima (14%), O. sativa-japonica (7%), O. sativa-indica Group 1 (45%), and O. sativa-indica Group 2 (25%). Severe versus mild stress in the field was associated with a reduced SPAD value (12%), biomass (56%), and grain yield (57%), with leaf bronzing explaining 30% and 21% of the variation for biomass and grain yield, respectively. Association mapping using 175 indica genotypes identified 23 significant single nucleotide polymorphism (SNP) markers that mapped to 14 genomic regions. Genome-wide association study (GWAS) signals associated with leaf bronzing, a routinely used indicator of HIA stress, differed in hydroponic compared with field conditions. Contrastingly, six significant SNPs on chromosomes 8 and 9 were associated with the SPAD value under HIA stress in both field and hydroponic experiments, and a candidate potassium transporter gene mapped under the peak on chromosome 8. This study helps define criteria for assessing rice performance under HIA environments.