title: Effects of Nitrogen and Shading on Root Morphologies, Nutrient Accumulation, and Photosynthetic Parameters in Different Rice Genotypes.
abstract: Nitrogen availability and illumination intensity are two key factors which affect rice growth. However, their influences on total nitrogen accumulation, photosynthetic rate, root morphologies, and yields are not fully understood. We conducted two field experiments to (1) evaluate the effects of shading under different N treatments on photosynthetic parameters, root morphologies, total nutrient accumulation, and grain yields of rice; and (2) elucidate the relationship between total nutrient accumulation and root morphologies under different shading conditions and nitrogen treatments. Three nitrogen rates, three shading treatments, and three different rice cultivars were used in two field experiments. Double shading during the grain-filling stage decreased total nutrient accumulation, altered root morphological characteristics, and decreased yields in rice. There were also significant interaction effects between nitrogen and shading on photosynthetic rate, transpiration rate, and total root length, root superficial area, and root volume. Significant interactions were found among cultivars and shading for photosynthetic rate and transpiration rate. Correlation analysis revealed that total nitrogen accumulation (TNA) and potassium accumulation (TKA) were significantly positively correlated with total root length, root superficial area, and root volume. N application could alleviate the detrimental effects of shading on total nutrient accumulation and grain yield in rice.
authors.affiliation: College of Agriculture, South China Agricultural University, Guangzhou, China.
authors.forename: Shenggang
authors.initials: S
authors.lastname: Pan
authors.affiliation: College of Agriculture, South China Agricultural University, Guangzhou, China.
authors.forename: Haidong
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Agriculture, South China Agricultural University, Guangzhou, China.
authors.forename: Zhaowen
authors.initials: Z
authors.lastname: Mo
authors.affiliation: College of Agriculture and Life Science, North Carolina State University, NC, United States.
authors.forename: Bob
authors.initials: B
authors.lastname: Patterson
authors.affiliation: College of Agriculture, South China Agricultural University, Guangzhou, China.
authors.forename: Meiyang
authors.initials: M
authors.lastname: Duan
authors.affiliation: College of Agriculture, South China Agricultural University, Guangzhou, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Tian
authors.affiliation: Department of Plant pathology, North Carolina State university, NC, United States.
authors.forename: Shuijin
authors.initials: S
authors.lastname: Hu
authors.affiliation: College of Agriculture, South China Agricultural University, Guangzhou, China.
authors.forename: Xiangru
authors.initials: X
authors.lastname: Tang
mesh_terms: D005838:Genotype; D008027:Light; D009584:Nitrogen / Q000378:metabolism*; D012275:Oryza / Q000235:genetics* / Q000502:physiology; D010758:Phosphorus / Q000378:metabolism; D010788:Photosynthesis; D018515:Plant Leaves / Q000502:physiology; D018517:Plant Roots / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D012639:Seeds / Q000254:growth & development
chemical_list: D010758:Phosphorus; D009584:Nitrogen; D011188:Potassium