Plants show different growth responses to N sources supplied with either NH4^＋ or NO3^-. The uptake of different N sources also affects the rhizosphere pH and therefore the bioavallability of soil phosphorus, particu...Plants show different growth responses to N sources supplied with either NH4^＋ or NO3^-. The uptake of different N sources also affects the rhizosphere pH and therefore the bioavallability of soil phosphorus, particularly in alkaline soils. The plant growth, P uptake, and P availability in the rhizosphere of oat （Arena nuda L.） grown in hydroponics and in soil culture were investigated under supply with sole NH4^＋-N, sole NO3-N, or a combination. Sole NO^- -fed oat plants accumulated more biomass than sole NH4^＋ -fed ones. The highest biomass accumulation was observed when N was supplied with both NH^＋ -N and NO3^- -N. Growth of the plant root increased with the proportion of NO3^- in the cultural medium. Better root growth and higher root/shoot ratio were consistently observed in NO3^- fed plants. However, root vigor was the highest when N was supplied with NO3^- ＋NH4^＋. NH4^＋ supply reduced the rhizosphere pH but did not affect P uptake by plants grown in soils with CaHPO4 added as P source. No P deficiency was observed, and plant P concentrations were generally above 2 g kg^-1. P uptake was increased when N was supplied partly or solely as NO3^--N, similarly as biomass accumulation. The results suggested that oat was an NO3-preferring plant, and NO3^- -N was essential for plant growth and the maintenance of root absorption capacity. N supply with NH4^＋ -N did not improve P nutrition, which was most likely due to the absence of P deficiency.展开更多
本试验采用5 s rDNA间隔序列分析和SRAP标记验证以色列野生二粒小麦与光稃野燕麦远缘杂种的真实性。结果表明,引物对PⅠ/PⅡ在以色列野生二粒小麦与光稃野燕麦杂种中扩增出了父本特异带,父本的遗传物质导入了小麦基因组。经SRAP标记分析...本试验采用5 s rDNA间隔序列分析和SRAP标记验证以色列野生二粒小麦与光稃野燕麦远缘杂种的真实性。结果表明,引物对PⅠ/PⅡ在以色列野生二粒小麦与光稃野燕麦杂种中扩增出了父本特异带,父本的遗传物质导入了小麦基因组。经SRAP标记分析,引物对me 3-em3在该杂种中也扩增出了父本特异带,进一步证明了杂种的真实性。展开更多
基金Project supported by the National Natural Science Foundation Council of China (No.30660086)the Natural Science Foundation of Inner Mongolia of China (No.200607010302)+2 种基金Hong Kong Research Grants Council (No.2465/05M)Hong Kong University Grants Committee (No.AOE/B-07/99)Hong Kong Baptist University Matching Research Fund.
文摘Plants show different growth responses to N sources supplied with either NH4^＋ or NO3^-. The uptake of different N sources also affects the rhizosphere pH and therefore the bioavallability of soil phosphorus, particularly in alkaline soils. The plant growth, P uptake, and P availability in the rhizosphere of oat （Arena nuda L.） grown in hydroponics and in soil culture were investigated under supply with sole NH4^＋-N, sole NO3-N, or a combination. Sole NO^- -fed oat plants accumulated more biomass than sole NH4^＋ -fed ones. The highest biomass accumulation was observed when N was supplied with both NH^＋ -N and NO3^- -N. Growth of the plant root increased with the proportion of NO3^- in the cultural medium. Better root growth and higher root/shoot ratio were consistently observed in NO3^- fed plants. However, root vigor was the highest when N was supplied with NO3^- ＋NH4^＋. NH4^＋ supply reduced the rhizosphere pH but did not affect P uptake by plants grown in soils with CaHPO4 added as P source. No P deficiency was observed, and plant P concentrations were generally above 2 g kg^-1. P uptake was increased when N was supplied partly or solely as NO3^--N, similarly as biomass accumulation. The results suggested that oat was an NO3-preferring plant, and NO3^- -N was essential for plant growth and the maintenance of root absorption capacity. N supply with NH4^＋ -N did not improve P nutrition, which was most likely due to the absence of P deficiency.
文摘本试验采用5 s rDNA间隔序列分析和SRAP标记验证以色列野生二粒小麦与光稃野燕麦远缘杂种的真实性。结果表明,引物对PⅠ/PⅡ在以色列野生二粒小麦与光稃野燕麦杂种中扩增出了父本特异带,父本的遗传物质导入了小麦基因组。经SRAP标记分析,引物对me 3-em3在该杂种中也扩增出了父本特异带,进一步证明了杂种的真实性。
