摘要
小麦春季生育期间，群体光合速率（ Ｃ Ｐ Ｒ） 的动态变化呈单峰曲线，于孕穗至开花期达到最大值，不同氮素用量处理 Ｃ Ｐ Ｒ 的峰值大小、峰值出现时间和高值持续期不同。群体单位叶面积光合速率（ Ｃ Ｐ Ｒｐａ） 与氮素用量呈显著负相关，高氮条件下 Ｃ Ｐ Ｒ 的提高主要起因于其群体叶面积的增大和冠层光截获率的增加。叶面积系数（ Ｌ Ａ Ｉ） 随氮素用量增加呈逐渐增大趋势，但高氮处理生育后期 Ｌ Ａ Ｉ的衰减速率较快。 Ｃ Ｐ Ｒ 与同期及相邻生育时期的 Ｌ Ａ Ｉ 呈显著正相关表明， Ｃ Ｐ Ｒ 与 Ｌ Ａ Ｉ两者之间存在着相互制约关系。生育中后期 Ｃ Ｐ Ｒ 的日变化呈单峰曲线。不同氮素处理生育期间群体干物质的累积量与 Ｃ Ｐ Ｒ 的表现相似， Ｃ Ｐ Ｒ 与同期及下一时期的群体干物质累积量成显著正相关。供试氮素范围内，整个春季生育阶段的群体叶源量（ Ｃ Ｌ Ｓ Ｃ） 随氮素用量增加呈抛物线型变化，施 Ｎ２２５ｋｇ·ｈ ｍ － ２ 处理群体叶源量最高，与开花期 Ｃ Ｐ Ｒ、开花 蜡熟 Ｃ Ｌ Ｓ Ｃ和同期 Ｃ Ｐ Ｒ 及 Ｌ Ａ Ｉ衰减速率的表现趋势相同。表明提高生育后期的群体光合速率，延长其高值持续时间，对于增加整个春季生育阶段的群体碳同化量具有重要作用。
During spring growth stages of wheat, the dynamic changes of canopy photosynthetic rate(CPR) showed one type curve with single peak. The maximum CPR were occured at booting stage or flowering stage. The application amount of nitrogen had important influence on the value, time of initiation and duration of the peak of CPR. Per canopy leaf photosynthetic rate(CPR pa ) was significantly negative correlated with the application amount of nitrogen. The increase of CPR in high amount treatments of nitrogen was mainly related to their increase of leaf area index(LAI) and light interception of canopy. Leaf area index(LAI) gradually increased with the increase of the amount of nitrogen, but the decline of LAI during late growth stages(booting to early ripening) in high nitrogen treatments were fast. CPR was significantly correlated with the LAI of same growth stage and next or last stage, which indicated that there were mutual effect between them. The diurnal changes of CPR basically showed one type curve with single peak. The population dry matter accumulation(PDW) at each nitrogen treatment were similar to its CPR, and at each growth stage, there were significantly positive correlations between CPR with PDW of the same and next growth stage. The changes of the canopy leaf source capacity(CLSC) showed a parabable curve, and peaked at the treatment of N 225kg·hm -2 , which has a same trend as the CPR of flowering stage and the senescing rate of CPR and LAI from flowering stage to ripening stage. It is suggested that increasing the canopy photosynthetic rate and delaying the senescence of CPR during late growth stage have important influence on population carbon assimilating capacity of spring growth stage.
出处
《植物营养与肥料学报》
CAS
CSCD
1999年第3期235-243,共9页
Journal of Plant Nutrition and Fertilizers
基金
"八五"农业部"重点应用基础研究"项目
关键词
小麦
群体光合碳同化
氮素营养
Wheat
Canopy photosynthetic carbon assimilation
Nitrogen nutrition
