摘要
利用农田开放式空气CO_2浓度增高(FACE,free-air carbon dioxide enrichment)系统,以武香粳14为试验材料,CO_2浓度设正常CO_2(AMB)和高CO2(FACE,AMB+200μL·L^(-1))2个水平,施氮量设低氮(LN,150kg·hm^(-2))和高氮(HN,350kg·hm^(-2))2个水平,研究CO_2与N的互作对水稻结实期剑叶叶绿素a、b、a+b含量以及叶绿素a/b值的影响。结果表明,不同施氮量平均,水稻抽穗后5d和10d,FACE处理剑叶叶绿素a、b以及a+b含量平均较AMB增加2.8%￣3.9%、2.8%￣5.7%和2.9%￣4.3%,而抽穗后15￣25d,FACE处理剑叶叶绿素含量分别较AMB下降2.2%￣3.3%、4.6%￣10.9%、3.7%￣4.7%;对剑叶叶绿素a/b值而言,抽穗后5￣10dFACE处理较ABM下降了1.6%￣3.3%,但使抽穗后15￣25d增加了2.5%￣7.8%;与LN相比,HN处理提高了FACE水稻结实前期剑叶叶绿素a、b及a+b含量的增幅,但使结实中后期的降幅变小;与此同时,HN处理使结实前期FACE水稻剑叶叶绿素a/b值的下降幅度增加,但使结实中、后期的增加幅度下降。上述结果说明,未来大气高CO2浓度情形下,水稻灌浆前期叶片的光合能力增强,但灌浆中后期稻叶的衰老加快;增施氮肥,可以促进水稻灌浆初期稻叶叶绿素含量的提高,延缓灌浆中、后期稻叶叶绿素含量的下降。
A free air co2 enrichment （FACE） experiment was conducted to investigate the interactive effects of elevated[CO2] and nitrogen （N） on chlorophyll content and composition in flag leaves during grain filling stage of rice, using the japonica cuhivar Wuxiangjing 14. The target [CO2] of the FACE plots was 200 IxL.L-I above that in the ambient air. Two levels of N were supplied： low （LN, 15 kg·hm^-2） and high N （HN, 35 kg· hm^-2）. Results showed that for averaged all N levels, FACE increased the contents of chlorophyll a, b and a＋b in top leaves of rice at 5- 10 d after heading （DAH）, averaging 2.8%-3.9%, 2.8%-5.7% and 2.8%-5.7%, respectively, while the contents of chlorophyll a, b and a＋b in top leaves of rice during 15 to 25 DAH was reduced by 2.2%-3.3%, 5.5%-11.0% and 5.5%-6.3%, respectively. As for the ratio of chlorophyll a/b, FACE crops showed a reduction of 1.6%-3.3% during 5-10 DAH, while an average increase of 2.5%-7.8% was detected during 15 to 25 DAH. The positive responses of chlorophyll a, b and a＋b to FACE during the early stage of grain filling were increased with increas- ing N rate, while the negative responses of chlorophyll a, b and a＋b during the middle and late stages of grain filling were reduced with increasing N level. In addition, the negative response of chlorophyll a/b to FACE during the early stage of grain filling was increased with increasing N rate, while the positive responses of chlorophyll a/b during the middle and late stages of grain filling were reduced with increasing N. This suggested that photosynthetic capacity of rice leaves was enhanced during the early stage of grain filling, while the rate of leaf senescence was accelerated during middle and late stage of grain filling under further elevated[CO2], and nitrogen availability had a large effect on the responses of leaf chlorophyll to elevated[CO2].
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2007年第4期1322-1326,共5页
Journal of Agro-Environment Science
基金
国家自然科学基金项目(3020777
30671226)
国家自然科学基金重大国际合作项目(40120140817)
中国科学院知识创新重要方向项目(KZCX-2-408)
