高CO2浓度、干旱及其互作对不同持绿型小麦幼苗的影响

以小麦持绿型品种‘烟农19'和非持绿型品种‘旱选3号'为试材,在开放式气室(OTC)内设置正常CO₂浓度(370 μmol·mol^-1)和高CO₂浓度(550 μmol·mol^-1),干旱(田间持水量的45%～55%)和灌溉(田间持水量的75%～85%),共4个环境处理,采用盆栽法研究高CO₂浓度、干旱及其互作对不同持绿型小麦幼苗生长性状、生物量积累和生理性状的影响。结果表明: 干旱显著抑制了小麦幼苗的生长发育;高CO₂浓度对小麦幼苗的生长发育有明显的促进作用,对分蘖数的影响更显著,干旱条件下高CO₂浓度使旱选3号和烟农19的分蘖数分别增加了61.0%和42.3%。两种水分条件下,高CO₂浓度显著增加了小麦幼苗的生物量,降低了幼苗叶片过氧化物酶和脯氨酸的含量。干旱条件下,高CO₂浓度表现出更好的“肥效作用”。此外,不同持绿型小麦品种对高CO₂浓度的响应存在差异,旱选3号对CO₂的响应更敏感。因此,在未来气候变化背景下,CO₂浓度升高时可以适当减少田间灌水量,合理利用水资源,还需注意选择适宜的品种。

Effects of high CO2 concentration,drought, and their interaction on different stay-green wheat seedlings

In this study, a pot experiment was carried out to examine the effects of high CO₂ concentration, drought and interaction on seedling growth traits, biomass accumulation and physiological characteristics of different stay-green wheat seedlings, with a stay-green wheat variety Yannong 19 and a non stay-green wheat variety Hanxuan 3 as test materials. There were four treatments in the Open Top Chamber with factorial of CO₂ concentration (370 μmol·mol^-1 vs 550 μmol·mol^-1) and drought (45%-55% vs. 75%-85% of field water-holding capacity). Drought significantly inhibited the growth and development of wheat seedlings, while CO₂ concentration significantly increased the number of tillers and promoted the growth and development of wheat seedlings. Under drought condition, high CO₂ concentration increased the number of tillers of Hanxuan 3 and Yannong 19 by 61.0% and 42.3%, respectively. Under both water conditions, high CO₂ concentration significantly increased the biomass of wheat seedlings, and decreased the content of peroxidase and proline in leaves. Under drought condition, high CO₂ concentration showed stronger “fertilizer effect”. Furthermore, different varieties had different responses to high CO₂ concentration, with higher sensitivity of Hanxuan 3 to enhancement of CO₂ concentration. Under the scenario of increasing CO₂ concentration, the amount of irrigation water applied to a field can be appropriately reduced for efficient use of water resources. Meanwhile, it is necessary to pay attention to the selection of suitable wheat varieties.