Evaluation of rice wild relatives as a source of traits for adaptation to iron toxicity and enhanced grain quality

Abstract

Rice wild relatives (RWR) constitute an extended gene pool that can be tapped for the breeding of novel rice varieties adapted to abiotic stresses such as iron (Fe) toxicity. Therefore, we screened 75 Oryza genotypes including 16 domesticated O. sativa genotypes, one O. glaberrima, and 58 RWR representing 21 species, for tolerance to Fe toxicity. Plants were grown in a semi-artificial greenhouse setup, in which they were exposed either to control conditions, an Fe shock during the vegetative growth stage (acute treatment), or to a continuous moderately high Fe level (chronic treatment). In both stress treatments, foliar Fe concentrations were characteristic of Fe toxicity, and plants developed foliar stress symptoms, which were more pronounced in the chronic Fe stress especially toward the end of the growing season. Among the genotypes that produced seeds, only the chronic stress treatment significantly reduced yields due to increases in spikelet sterility. Moreover, a moderate but non-significant increase in grain Fe concentrations, and a significant increase in grain Zn concentrations were seen in chronic stress. Both domesticated rice and RWR exhibited substantial genotypic variation in their responses to Fe toxicity. Although no RWR strikingly outperformed domesticated rice in Fe toxic conditions, some genotypes scored highly in individual traits. Two O. meridionalis accessions were best in avoiding foliar symptom formation in acute Fe stress, while an O. rufipogon accession produced the highest grain yields in both chronic and acute Fe stress. In conclusion, this study provides the basis for using interspecific crosses for adapting rice to Fe toxicity. , et al.(2020) Evaluation of rice wild relatives as a source of traits for adaptation to iron toxicity and enhanced grain quality. PLoS ONE 15(1): e0223086. https://doi.org/10.

Genetic Diversity and Phylogenetic Position of Traditional Rice (Oryza sativa L.) Landraces: A Case Study of South Kalimantan in Indonesia

“…The Tajima neutrality test (D) has also supported this condition, where this germplasm has an indicating the expansion of population size (for example, after a purifying selection or bottleneck) because all sequences have negative values (D<0) (Korneliussen et al, 2013). Consequently, future rice improvement must be oriented to outcrossing, as was employed by Niruntrayakul et al (2009) and Bierschenk et al (2020). According to Gaikward et al (2021), most wild rice relatives have novel beneficial alleles for improving cultivated rice varieties, such as better adaptation to different ecological regimes and biotic and abiotic stresses.…”

Below-ground plant-soil interactions affecting adaptations of rice to iron toxicity

“…From these and other studies it can be concluded that ample genetic variation for tolerance to Fe toxicity exists within theO. sativa gene pool (Matthus et al 2015;Pawar et al 2021), and that wild relatives may serve as sources of novel traits enhancing adaptation to Fe toxicity (Bierschenk et al 2020;Wairich et al, 2021).…”

Iron Biofortification in Rice: An Update on Quantitative Trait Loci and Candidate Genes

“…However, no gene with similar function was found in rice despite several efforts ( Sperotto et al, 2009 ; Distelfeld et al, 2012 ; Jeong et al, 2013 ). Therefore, wild relatives of wheat are an interesting source of genetic variability for improving Fe concentration in cultivated wheat varieties, an approach that can be used with wild rice species ( Ricachenevsky and Sperotto, 2016 ; Bierschenk et al, 2020 ; Wairich et al, 2020 ).…”