FACE条件下冬小麦生长特征及产量构成的影响

Effect of Free Air CO_2 Enrichment (FACE) on the Growth and Grain Yield of Winter Wheat

模拟2050年冬小麦生长的CO2浓度下,冬小麦生长和产量的响应,有助于评价未来CO2浓度升高对小麦生产的影响。利用农田开放式大气CO2浓度升高(FACE)试验平台,以强筋冬小麦CA0493为供试材料,CO2浓度处理设定对照CO2(aCO2,415±16μmol/mol)和高浓度CO2(eCO2,550±17μmol/mol)2个水平;施N处理设常规施氮(NN,底肥含N118kg/hm2+追肥含N70kg/hm2)和低氮(LN,底肥含N66kg/hm2+追肥含N17kg/hm2)2个水平,研究高浓度CO2和不同施氮量对冬小麦株高、叶面积、分蘖动态、产量和产量构成要素的影响。结果表明,高CO2浓度显著提高了拔节期小麦株高(5.12%),常规施氮下的增幅高于低氮下的增幅。CO2浓度升高显著增加了开花期的旗叶面积(14.87%)和主茎上部3叶叶面积(10.02%),旗叶叶面积的增加主要由叶长增加(8.97%)决定。CO2浓度升高使常规施氮下的分蘖数量增加。开放式CO2浓度升高使冬小麦产量增加18.3%(P<0.05),低氮和常规施氮下的增幅分别为6.0%、31.4%。高浓度CO2使小麦单位面积穗数和穗粒数分别增加5.3%和14.5%(P<0.05),常规施氮下的增幅均高于低氮下的增幅,不孕小穗数下降11.12%(P<0.05),而对千粒重无显著影响。高浓度CO2使不孕小穗数降低,小花退化减少,从而提高了穗粒数,是产量增加的主要原因。

Simulating on the atmosphere C02 concentration in 2050 in a wheat field, investigating on thegrowth and yield response of winter wheat to elevated C02, enable people to estimate the impacts of elevated C02 on winter wheat in a C02-rich world. Winter wheat （Triticum aestivum L. cv CA0493, high gluten wheat）was grown to maturity at ambient CO2 （415±16 μmol/mol） or elevated CO2 （550±17 μmol/mol） under 2 levels of N： normal N （NN, basal dressing N 118 kg/hm%sidedressing N 70 kg/hm2） and low N （LN, basal dressing N 66 kg/hm2＋sidedressing N 17 kg/hm2） at FACE （Free Air CO2 Enrichment） system, to investigate the effects of elevated CO2 （550 Ixmol/mol） and N fertilizer input on height, flag leaf area and the top three leaves area, tillernumber seasonal changes, grain yield and yield components of winter wheat, llesults showed that elevated CO2 increased wheat height by 5.12% at jointing stage, the scale of increasing was larger under normal N than low N input. Elevated C02 increased flag leaf area and the top three leaves area by 14.87%, 10.02% at flowering stage, respectively. Increased leaf size under elevated CO2 was determined by longer leaf length （8.97%）. Elevated C02 tend to increase the tiller number under normal N input. Grain yield increased by 18.3% under elevated C02 （P〈0.05）, with 6% in low N input and 31.4% in normal N input. Panicle number per square meter and grain number per panicle increased by 5.3% and 14.5% （P〈0.05） under elevated C02, and the increase amplitude was more in normal N than low N input. Infertile spikelet number decreased significantly by 11.12% at high C02, while thousand grains weight showed no significant change under elevated CO2. Elevated CO2 reduced the degenerated spikelet number, thus increased yield increase under elevated CO2. grain number per panicle, which accounted for theyield increase under elevated C02.