A glasshouse experiment was conducted using a root-bag technique to study the root exudates, rhizosphere Zn fractions, and Zn concentrations and accumulations of two ryegrass cultivars （Lolium perenne L. cvs. Airs an...A glasshouse experiment was conducted using a root-bag technique to study the root exudates, rhizosphere Zn fractions, and Zn concentrations and accumulations of two ryegrass cultivars （Lolium perenne L. cvs. Airs and Tede） at different soil Zn levels （0, 2, 4, 8, and 16 mmol kg^-1 soil）. Results indicated that plant growth of the two cultivars was not advérsely affected at soil Zn level ≤ 8 mmol kg^-1. Plants accumulated more Zn as soil Zn levels increased, and Zn concentrations of shoots were about 540 μg g^-1 in Aris and 583.9 μg g^-1 in Tede in response to 16 mmol Zn kg^-1 soil. Zn ratios of shoots to roots across the soil Zn levels were higher in Tede than in Airs, corresponding with higher rhizosphere available Zn fractions （exchangeable, bound to manganese oxides, and bound to organic matter） in Airs than in Tede. Low-molecular-weight （LMW） organic acids （oxalic, tartaric, malic, and succinic acids） and amino acids （proline, threonine, glutamic acid, and aspartic acid, etc.） were detected in root exudates, and the concentrations of LMW organic acids and amino acids increased with addition of 4 mmol Zn kg^-1 soil compared with zero Zn addition. Higher rhizosphere concentrations of oxalic acid, glutamic acid, alanine, phenylalanine, leucine, and proline in Tede than in Airs likely resulted in increased Zn uptake from the soil by Tede than by Airs. The results suggested that genotypic differences in Zn accumulations were mainly because of different root exudates and rhizosphere Zn fractions.展开更多
Pearling is an effective method for evaluating the distribution of chemical components in wheat grain. Five pearling fractions （representing approximately 20% of the original sample weight） of wheat grain were obtai...Pearling is an effective method for evaluating the distribution of chemical components in wheat grain. Five pearling fractions （representing approximately 20% of the original sample weight） of wheat grain were obtained using the JNMJ3 rice polisher for two cultivars with different methods of Zinc （Zn） application; the residual portion （approximately 80%） was ground as flour. Results showed that folJar or soil＋foliar Zn application methods effectively increased Zn concentrations and bioavailability in whole grain and pearling fractions, but soil Zn application was ineffective in field conditions. In addition, the concentrations of Zn, Fe, Mn and Cu within wheat grain showed a diminishing trend from the outer layer to the inner portions of the wheat grain as the pearling level increased. These results cleady showed the distribution of minerals in wheat grain, especially in the outer part of the grain （bran）. The results also suggest that precise milling techniques combined with foliar Zn ap- plication could improve the Zn and Fe nutritional qualities of consumed flour and mitigate human Zn and Fe deficiencies.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 20477032).
文摘A glasshouse experiment was conducted using a root-bag technique to study the root exudates, rhizosphere Zn fractions, and Zn concentrations and accumulations of two ryegrass cultivars （Lolium perenne L. cvs. Airs and Tede） at different soil Zn levels （0, 2, 4, 8, and 16 mmol kg^-1 soil）. Results indicated that plant growth of the two cultivars was not advérsely affected at soil Zn level ≤ 8 mmol kg^-1. Plants accumulated more Zn as soil Zn levels increased, and Zn concentrations of shoots were about 540 μg g^-1 in Aris and 583.9 μg g^-1 in Tede in response to 16 mmol Zn kg^-1 soil. Zn ratios of shoots to roots across the soil Zn levels were higher in Tede than in Airs, corresponding with higher rhizosphere available Zn fractions （exchangeable, bound to manganese oxides, and bound to organic matter） in Airs than in Tede. Low-molecular-weight （LMW） organic acids （oxalic, tartaric, malic, and succinic acids） and amino acids （proline, threonine, glutamic acid, and aspartic acid, etc.） were detected in root exudates, and the concentrations of LMW organic acids and amino acids increased with addition of 4 mmol Zn kg^-1 soil compared with zero Zn addition. Higher rhizosphere concentrations of oxalic acid, glutamic acid, alanine, phenylalanine, leucine, and proline in Tede than in Airs likely resulted in increased Zn uptake from the soil by Tede than by Airs. The results suggested that genotypic differences in Zn accumulations were mainly because of different root exudates and rhizosphere Zn fractions.
基金supported by Chongqing Talent Plan:Leading Talents in Innovation and Entrepreneurship,China(No.CQYC201903051)University Innovation Research Group of Chongqing,China(No.CXQT20023)+4 种基金Qingnian Project of Science and Technology Research Program of Chongqing Municipal Education Commission,China(No.KJQN202001106)China Postdoctoral Science Foundation(No.2021M700556)Natural Science Foundation of Chongqing,China(No.cstc2021jcyj-bsh X0114)Natural Science Foundation of China(Nos.U20A20234,51874062)Chongqing Foundation and Advanced Research Project,China(No.cstc2019jcyj-zdxm X0010)。
基金supported by the National Natural Science Foundation of China (41371288 and 31672233)the National Key Technologies R&D Programs of China during the 12th Five-Year Plan period (2012BAD14B11)
文摘Pearling is an effective method for evaluating the distribution of chemical components in wheat grain. Five pearling fractions （representing approximately 20% of the original sample weight） of wheat grain were obtained using the JNMJ3 rice polisher for two cultivars with different methods of Zinc （Zn） application; the residual portion （approximately 80%） was ground as flour. Results showed that folJar or soil＋foliar Zn application methods effectively increased Zn concentrations and bioavailability in whole grain and pearling fractions, but soil Zn application was ineffective in field conditions. In addition, the concentrations of Zn, Fe, Mn and Cu within wheat grain showed a diminishing trend from the outer layer to the inner portions of the wheat grain as the pearling level increased. These results cleady showed the distribution of minerals in wheat grain, especially in the outer part of the grain （bran）. The results also suggest that precise milling techniques combined with foliar Zn ap- plication could improve the Zn and Fe nutritional qualities of consumed flour and mitigate human Zn and Fe deficiencies.
