Genome-Wide Association Study and Identification of Candidate Genes for Nitrogen Use Efficiency in Barley (Hordeum vulgare L.)
MetadataShow full item record
Nitrogen (N) fertilizer is largely responsible for barley grain yield potential and quality, yet excessive application leads to environmental pollution and high production costs. Therefore, efficient use of N is fundamental for sustainable agriculture. In the present study, we investigated the performance of 282 barley accessions through hydroponic screening using optimal and low NH<sub>4</sub>NO<sub>3</sub> treatments. Low-N treatment led to an average shoot dry weight reduction of 50%, but there were significant genotypic differences among the accessions. Approximately 20% of the genotypes showed high (>75%) relative shoot dry weight under low-N treatment and were classified as low-N tolerant, whereas 20% were low-N sensitive (≤55%). Low-N tolerant accessions exhibited well-developed root systems with an average increase of 60% in relative root dry weight to facilitate more N absorption. A genome-wide association study (GWAS) identified 66 significant marker trait associations (MTAs) conferring high nitrogen use efficiency, four of which were stable across experiments. These four MTAs were located on chromosomes 1H(1), 3H(1), and 7H(2) and were associated with relative shoot length, relative shoot and root dry weight. Genes corresponding to the significant MTAs were retrieved as candidate genes, including members of the asparagine synthetase gene family, several transcription factor families, protein kinases, and nitrate transporters. Most importantly, the high-affinity nitrate transporter 2.7 (HvNRT2.7) was identified as a promising candidate on 7H for root and shoot dry weight. The identified candidate genes provide new insights into our understanding of the molecular mechanisms driving nitrogen use efficiency in barley and represent potential targets for genetic improvement.
Showing items related by title, author, creator and subject.
Effects of irrigation rate on the growth, yield, nutritive value, and water use efficiency of Carrot (Daucus carota) and Broccoli (Brasiola oleracea)Ludong, Daniel Peter M. (2008)The effects of differential irrigation treatments on the water use of broccoli (c.v. Indurance) and carrots (c.v. Stefano) were studied in the rainy, winter season from July to September 2006 and in the dry, summer period ...
Florentine, Singarayer K. (1999)The WA coolibah tree, Eucalyptus victrix L. Johnson & K. Hill forms an unique and pristine woodland in the Fortescue Valley, in the Pilbara district of Western Australia. Until recently, no research had been done on E. ...
Terrestrial ecosystems, increased solar ultraviolet radiation and interactions with other climatic change factorsCaldwell, M.; Bornman, Janet; Ballare, C.; Flint, S.; Kulandaivelu, G. (2007)There have been significant advances in our understanding of the effects of UV-B radiation on terrestrial ecosystems, especially in the description of mechanisms of plant response. A further area of highly interesting ...