开放式空气二氧化碳浓度增高对小麦物质生产与分配的影响

2001—2003年，利用农田开放式空气CO₂浓度增高 (FACE) 技术平台，以冬小麦宁麦9号为供试材料，研究开放式条件下CO₂浓度增高对小麦整个生育期干物质生产与分配的影响.结果表明：与对照相比，FACE处理使小麦播种-越冬始期的干物质生产量略有增加（10.8%)，使越冬始期-拔节期、拔节期-孕穗期、孕穗期-抽穗期显著增加，分别增加了31.6%、40.5%、27.2%，使抽穗期-成熟期略有减少(-5.5%)，使成熟期生物产量显著增加(13.6%)；FACE处理对小麦播种-越冬始期的平均叶面积系数(LAI)和净同化率(NAR)均无显著影响，但使越冬始期-抽穗期LAI显著增加，NAR稍有增加，使抽穗期-抽穗后20 d NAR显著下降；FACE处理使不同生育时期叶片占全株质量的比例下降，而使茎鞘占全株质量的比例增加；FACE小麦抽穗期和成熟期茎鞘可溶性糖和淀粉含量及总量均明显增加.

Effects of free-air CO2 enrichment (FACE) on dry matter production and allocation in wheat

A free-air CO2 enrichment (FACE) experiment was conducted in 2001-2003 to study the effects of predicted higher CO2 levels on the dry matter (DM) production and allocation in winter wheat variety Ningmai 9. The results showed that under FACE, the DM production had an increase of 10. 8% , 31. 6% , 40. 5% and 27. 2% during the growth periods from sowing to wintering ( Period 1 ) , wintering to jointing ( Period 2) , jointing to booting ( Period 3) , and booting to heading (Period 4) , respectively, but a decrease of 5. 5% in the period from heading to grain maturity (Period 5). As a result, the final total biomass at maturity was increased by 13. 6%. FACE had no significant effect on leaf area index (LAI) and net assimilation rate (NAR) in Period 1, but made the LAI in Period 2 increased obviously, and the NAR decreased dramatically in Period 3. Under FACE, the proportion of leaf to total above-ground DM decreased, while that of stem (including sheath) to total above-ground DM showed an opposite trend in the whole growth period. The percentage and total amount of soluble sugar and starch in the stem at grain-filling stage were also increased obviously under FACE.