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
Institut Sénégalais de Recherches Agricoles/Centre de Recherches Agricoles de Djibélor, Ziguinchor, Senegal.
West Africa Centre for Crop Improvement, University of Ghana, Legon, Ghana.
J Exp Bot. 2020 Jul 6;71(14):4188-4200. doi: 10.1093/jxb/eraa182.
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 FeSO4·7H2O) 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.
采用在高铁相关（HIA）胁迫环境下表现良好的水稻品种，可以提高西非的水稻产量。本研究报告了利用简化基因组测序对在西非种植的323份水稻种质资源和育种系进行的遗传特征分析，以及它们在水培溶液（1500 mg l-1 FeSO4·7H2O）和热点田间对HIA处理的表型反应。种质由四个遗传亚群组成：光稃稻（14%）、粳稻（7%）、籼稻第1组（45%）和籼稻第2组（25%）。田间重度胁迫与轻度胁迫相比，叶绿素仪读数（SPAD值）降低了12%，生物量降低了56%，籽粒产量降低了57%，叶黄化分别解释了生物量和籽粒产量变异的30%和21%。利用175份籼稻基因型进行的关联分析鉴定出23个显著的单核苷酸多态性（SNP）标记，这些标记定位于14个基因组区域。与叶黄化（HIA胁迫的常用指标）相关的全基因组关联研究（GWAS）信号在水培条件下与田间条件下有所不同。相比之下，在田间和水培试验中，第8和9号染色体上的6个显著SNP与HIA胁迫下的SPAD值相关，并且在第8号染色体的峰值下定位到一个候选钾转运蛋白基因。本研究有助于确定评估水稻在HIA环境下性能的标准。
