开放式空气CO_2浓度增加(FACE)对水稻产量形成的影响及其与氮的互作效应

Effects of Free-Air CO_2 Enrichment (FACE) on Yield Formation of Rice (Oryza sativa L.) and Its Interaction with Nitrogen

2001～2003年,在大田条件下以武香粳14号为供试品种,设计高、中、低氮处理,研究开放式空气CO2浓度增加(FACE)200μmolmol-1对水稻产量形成的影响及其原因。结果表明,FACE处理使水稻产量平均比对照增加12.8%,其中2001、2002和2003年增幅分别为10.8、14.1和13.6%,高、中、低氮处理的增幅分别为17.6、12.4、10.9%,均达到显著或极显著水平;FACE和氮处理对水稻产量的互作效应,2001、2002年达到显著水平,产量最高的处理组合为FACE×NN;FACE处理使水稻穗数平均比对照增加18.8%,每穗颖花数平均比对照减少7.6%,均达极显著水平;FACE处理使水稻生物产量平均提高16.2%,达极显著水平,使经济系数下降但未达到显著水平。进一步研究表明,FACE处理使水稻穗数极显著多于对照是因其分蘖发生速度快,最高分蘖数多所致,而不是其分蘖成穗率高的缘故;FACE处理使水稻每穗颖花数极显著少于对照是因其分化颖花的大量退化所致,而不是分化颖花数少的缘故。

In order to investigate the effect of the predicted higher levels of CO2 on yield and its formation of rice (Oryza sativa L.) crops, a free-air CO2 enrichment (FACE) experiment was conducted at Anzhen,Wuxi,Jiangsu Province,in 2001-2003,using the japonica cultivar Wuxiangjing 14. The target [CO2] of the FACE plots was 200 靘ol穖ol-1 above that in the ambient air. Three levels of N were supplied:low (LN,150 kg穐a-1),normal (NN,250 kg穐a-1) and high N(HN,350 kg穐a-1). Results showed that FACE significantly increased grain yield by an average 12.8% over three seasons of rice, with average value of the data in 2001, 2002 and 2003 increased 10.8%, 14.1% and 13.6%, respectively. For HN, NN and LN-levels, rice yields under FACE treatment were increased by averages of 17.6%, 12.4% and 10.9%, respectively. The significant effect of interaction between CO2 concentration and N on rice yield was found in 2001 and 2002, and the treatment of the highest rice yield was FACE譔N. Number of panicles per unit ground area under FACE treatment was very significantly increased by an average of 18.8%, while spikelet number per panicle was very significantly decreased by an average of 7.6%. Total biomass was increased very significantly by an average of 16.2%, while economic coefficient was decreased slightly. Further analyses showed that significant increase of panicles per unit ground area due to FACE were related to substantial increase of tiller formation, while percentage of productive tiller (panicle bearing) under FACEtreatment was reduced. Significantly decrease of survived spikelets per panicle due to FACE was chiefly caused by marked increase of the number and percentage of retrograded spikelets on panicle.