Nitrogen is an essential nutrient for crop growth and development. Although the functions of several genes associated with nitrogen deficiency tolerance have been studied, many genetic components remain unknown. In this study, 190 North Korean (NK) rice genotypes were used to identify genes linked to nitrogen deficiency resistance. The NK population was hydroponically cultivated for 31 days under normal nitrogen (NN) and low nitrogen (LN) conditions. After this period, phenotypic evaluations were conducted on six agronomic traits (SPAD, shoot length, root length, shoot fresh weight, root fresh weight, and tiller number). A genome-wide association study (GWAS) was performed using the phenotypic values and resequencing data from 190 NK rice genotypes. As a result, 107 significant lead SNPs were identified. Among the genes related to these lead SNPs, 12 previously identified NUE-related genes for nitrogen use efficiency (NUE) and 6 unknown candidate genes exhibited significant differences in haplotype analysis. Nine of the 12 known genes (
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A total of 857 rice breed lines were used to evaluate rice blast resistance. Frequency of leaf spot index was skewed to the right of the 1-9 scale in bar plot, with a score of 7 showing the highest frequency. The average spot index score of 857 breed lines was 5.33. Associations showing higher than the threshold of ‒log10(P) = 5.17 were detected as significant associations. Significantly associated single nucleotide polymorphism (SNP) markers located within ± 250 kb on the lead SNP position was designated to one QTL locus of lead SNP markers. Five association loci were detected. Two associated QTLs detected on Chr. 4 were designated as qRB4.1 and qRB422, explaining 17.8% and 14.3% of total phenotypic variations, respectively. Associated QTLs detected on Chr. 1, 11, and 12 (one each) designated as qRB1, qRB11 and qRB12 explained 44.6%, 9.09%, and 13.7% of total phenotypic variations, respectively. We compared previously reported QTLs. The location of qRB4.2 was overlapped with the previously reported QTL for blast field resistance. The location of qRB12 was also overlapped with the field resistance leaf blast. The other one, qRB4.1, was overlapped with bacterial blight resistance.
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Rice is a temperature-sensitive crop, its yield is severely affected by low temperature, especially cold stress at the seedling stage will delay heading. To understand the genetic basis of cold tolerance, we evaluated the cold tolerance at the seedling stage of 136 rice accessions. To evaluate cold tolerance, we treated rice seedlings with cold water irrigation for ten days and scored the cold tolerance on a 1-9 scale, based on their low-temperature response and subsequent recovery. The genome-wide association study for cold tolerance revealed seven QTLs on chromosomes 1, 3, 6, 7, 10, and 12. The genomic region of the
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Cowpea is an annual legume crop; although it is an essential food in developing countries, cowpea is now grown worldwide. For the genetic improvement of plants, flowering time is one of the major selection criteria. In general, flowering is regulated by photoperiod and temperature, along with the interaction between environmental factors. In this study, we aimed to investigate the candidate genes associated with flowering time using genome-wide association study (GWAS). To investigate the flowering time-related genes, 384 cowpea germplasms were genotyped with 51,128 single nucleotide polymorphisms (SNPs). The main genetic component of days to flowering (DTF) was analyzed using genome association and prediction integrated tool (GAPIT) and elastic-net analyses. From the GAPIT and elastic-net analyses, a total of 23 SNPs were significantly associated with DTF among five (chr. 2, 3, 7, 9, and 11) and seven (chr. 1, 2, 3, 4, 5, 8, and 9) different chromosomes, respectively. Based on our analysis,
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