In semiarid areas, cereal crops often alocate more biomass to root at the expense of aboveground yield. A pot experiment was conducted to investigate carbon consumption of roots and its impact on grain yield of spring...In semiarid areas, cereal crops often alocate more biomass to root at the expense of aboveground yield. A pot experiment was conducted to investigate carbon consumption of roots and its impact on grain yield of spring wheat （Triticum aestivum L.） as affected by water and phosphorus （P） supply. A factorial design was used with six treatments namely two water regimes （at 80–75% and 50–45% ifeld capacity （FC）） and three P supply rates （P1=0, P2=44 and P3=109 μg P g–1 soil）. At shooting and lfowering stages, root respiration and carbon consumption increased with the elevate of P supply rates, regardless of water conditions, which achieved the minimum and maximum at P1 under 50–45% FC and P3 under 80–75% FC, respectively. However, total aboveground biomass and grain yield were higher at P2 under 80–75% FC; and decreased with high P application （P3）. The results indicated that rational or low P supply （80–75% of ifeld water capacity and 44 mg P kg–1 soil） should be recommended to improve grain yield by decreasing root carbon consumption in semiarid areas.展开更多
Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici （Pst）, is a severe foliar disease of common wheat （Triticum aestivum L.） in the world. Resistance is the best approach to control the disease. Th...Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici （Pst）, is a severe foliar disease of common wheat （Triticum aestivum L.） in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene（s） for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 （M169）. Seedlings of the parents, and F 1 , F 2 and F 2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat （SSR） techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F 2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 97.9% of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.展开更多
基金supported by the National Nature Science Foundation of China (31300328, 31200335, 31470496)the "111" Program from State Administration of Foreign Experts Affairs (SAFEA) & Ministry of Education (MOE), China (2007B051)+1 种基金the Fundamental Research Funds for the Central Universities, China (lzujbky-2012-97, lzujbky-2015-ct02, lzujbky-2016-86)the funding from the State Key Laboratory of Grassland Agro-ecosystem in Lanzhou University, China
文摘In semiarid areas, cereal crops often alocate more biomass to root at the expense of aboveground yield. A pot experiment was conducted to investigate carbon consumption of roots and its impact on grain yield of spring wheat （Triticum aestivum L.） as affected by water and phosphorus （P） supply. A factorial design was used with six treatments namely two water regimes （at 80–75% and 50–45% ifeld capacity （FC）） and three P supply rates （P1=0, P2=44 and P3=109 μg P g–1 soil）. At shooting and lfowering stages, root respiration and carbon consumption increased with the elevate of P supply rates, regardless of water conditions, which achieved the minimum and maximum at P1 under 50–45% FC and P3 under 80–75% FC, respectively. However, total aboveground biomass and grain yield were higher at P2 under 80–75% FC; and decreased with high P application （P3）. The results indicated that rational or low P supply （80–75% of ifeld water capacity and 44 mg P kg–1 soil） should be recommended to improve grain yield by decreasing root carbon consumption in semiarid areas.
基金support of the 111 Project from the Ministryof Education of China(B07049)the Key Technologies R&D Program of China during the 11th Five-Year Plan period(2006BAD08A05)the project of Toxicity Variation of Wheat Stripe Rust Pathogen and Demonstration of Integrated Management of Stripe Rust,China(200903035-02)are thankfully acknowledged
文摘Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici （Pst）, is a severe foliar disease of common wheat （Triticum aestivum L.） in the world. Resistance is the best approach to control the disease. The winter wheat cultivar Lantian 1 has high-temperature resistance to stripe rust. To determing the gene（s） for the stripe rust resistance, Lantian 1 was crossed with Mingxian 169 （M169）. Seedlings of the parents, and F 1 , F 2 and F 2-3 progenies were tested with races CYR32 of Pst under controlled greenhouse conditions. Lantian 1 has a single partially dominant gene conferred resistance to race CYR32, designated as YrLT1. Simple sequence repeat （SSR） techniques were used to identify molecular markers linked to YrLT1. A linkage group of five SSR markers was constructed for YrLT1 using 166 F 2 plants. Based on the SSR marker consensus map and the position on wheat chromosome, the resistance gene was assigned on chromosome 2DL. Amplification of a set of nulli-tetrasomic Chinese Spring lines with SSR marker Xwmc797 confirmed that the resistance gene was located on the long arm of chromosome 2D. Because of its chromosomal location and the high-temperature resistance, this gene is different from previously described genes. The molecular map spanned 29.9 cM, and the genetic distance of two close markers Xbarc228 and Xcfd16 to resistance gene locus was 4.0 and 5.7 cM, respectively. The polymorphism rates of the flanking markers in 46 wheat lines were 2.1 and 2.1%, respectively; and the two markers in combination could distinguish the alleles at the resistance locus in 97.9% of tested genotypes. This new gene and flanking markers should be useful in developing wheat cultivars with high level and possible durable resistance to stripe rust.
