FACE对杂交籼稻汕优63干物质生产与分配的影响

Effect of Free Air CO2 Enrichmen(tFACE)on Production and Distribution of Dry Matter of Three-line Indica Hybrid Rice Cultivar Shanyou 63

2005—2006年利用我国惟一的农田开放式空气CO2浓度增高(FACE)研究平台,以三系杂交籼稻汕优63为供试材料,设计比大气CO2浓度(对照,370μmol·mol-1)高200μmol·mol-1的FACE处理(570μmol·mol-1)和施N量为125kg·hm-(2LN)、250kg·hm-(2NN)处理,研究其对汕优63物质生产与分配的影响。结果表明:(1)两季平均,FACE处理使汕优63移栽-分蘖中期、分蘖中期-拔节期、拔节-抽穗期和抽穗-成熟期干物质生产量分别比对照增加了39%、20%、32%和41%,结果使成熟期生物产量显著增加(+33%);(2)与干物质生产量相比,汕优63平均叶面积指数(LAI)和净同化率(NAR)对CO2的响应有相似的季节性变化趋势,但LAI的响应值明显大于NAR;(3)FACE处理使汕优63不同生育时期叶片和稻穗占地上部干重的比例下降,而使茎鞘占地上部干重的比例明显增加;(4)三系杂交籼稻汕优63成熟期生物产量以及不同生育阶段平均LAI、NAR和干物质生产量对FACE的响应与粳稻品种存在明显差异,而干物质分配差异较小。

In this study, the Chinese unique Free Air CO2 Enrichment [FACE, 200umol·mol^-1 higher than ambient CO2 concentration（AMB）] research platform was used to investigate the effects of FACE on dry matter（DM ）production and distribution of three-line indica hybrid rice cuhivar Shanyou 63 under two levels of N such as Low （LN, 125 kg· hm^-2） and normal N （NN, 250 kg· hm^-2）in 2005 and 2006. The results showed that throughout the two growing seasons, rice DM production under the FACE was significantly enhanced by 39%, 20%, 32% and 41% during the rice growth periods from transplanting to mid-tillering, mid-tillering to jointing, jointing to heading and heading to grain maturity, respectively. As a result, the final total biomass at maturity was increased by 33% on average. In general, the seasonal response of crop growth to the FACE in both leaf area index（LAI）and net assimilation rate（NAR）followed a similar pattern to those of the DM production, with a larger response in LAI than in NAR. Under the FACE, the weight of leaves and spikes was decreased in proportion to the total above-ground DM over the season, whereas the weight of stems was increased. There were large differences between the three-line indica hybrid rice cultivar and japonica rice cultivar in the responses of final DM accumulation to leveled CO2 concentrations at maturity stage, and in mean LAI and NAR, and DM production during the different growth periods, while differences in dry matter distribution of leaves, spikes and stems were small.