Search Results (2)

Rice is a major grain crop in numerous countries. In lowland areas, high iron levels in the soil severely hinder its cultivation. The current study explored high-yielding and Fe-toxicity-tolerant irrigated lowland rice (340 lines) among a population derived from a cross between Suakoko 8 and Bao Thai in Edozighi and Ibadan, Nigeria. In contrast to Ibadan, the soils in Edozighi contain a significant amount of iron. For the stated purpose, we carried out a two-year experiment using an alpha lattice design. The data showed significant differences between genotypes for the days to heading, plant height, number of tillers per plant, number of panicles per plant, panicle length, and grain yield. The results revealed that multiple characteristics had both direct and indirect effects on cultivated rice yields. There was a direct and positive influence on the number of days in the 50% heading period (0.31), a direct and negative effect on plant height (−0.94), a direct and positive effect on tiller and panicle numbers, and a direct but negative effect on panicle length (−0.56). The leaf bronzing score was adversely correlated with yield, panicle length, and plant height, while it was positively correlated with the number of panicles, tillers, and days to heading. The findings showed significant changes in yield and yield characteristics between genotypes. Grain yields ranged from 283 to 11,700 kg/ha in the absence of iron in the soil, contrary to 0 to 8230 kg/ha in soil with iron toxicity, with losses estimated between 6 and 94%, demonstrating the resulting disaster. In contrast to the elite parents and varieties used in this study, the ten top genotypes exhibited smaller losses in yield. The authors strongly recommend using these lines for further studies as donors or releasing them in farmer fields in Africa. Full article

Excess soluble iron in acidic soil is an unfavorable environment that can reduce rice production. To better understand the tolerance mechanism and identify genetic loci associated with iron toxicity (FT) tolerance in a highly diverse indica Thai rice population, a genome-wide association study (GWAS) was performed using genotyping by sequencing and six phenotypic data (leaf bronzing score (LBS), chlorophyll content, shoot height, root length, shoot biomass, and root dry weight) under both normal and FT conditions. LBS showed a high negative correlation with the ratio of chlorophyll content and shoot biomass, indicating the FT-tolerant accessions can regulate cellular homeostasis when encountering stress. Sixteen significant single nucleotide polymorphisms (SNPs) were identified by association mapping. Validation of candidate SNP using other FT-tolerant accessions revealed that SNP:2_21262165 might be associated with tolerance to FT; therefore, it could be used for SNP marker development. Among the candidate genes controlling FT tolerance, RAR1 encodes an innate immune responsive protein that links to cellular redox homeostasis via interacting with abiotic stress-responsive Hsp90. Future research may apply the knowledge obtained from this study in the molecular breeding program to develop FT-tolerant rice varieties. Full article