摘要
大气二氧化碳(CO_2)和近地层臭氧(O_3)浓度升高将极大地改变作物的生长环境,进而影响作物包括主要粮食作物的生产力。利用自然光气体熏蒸平台,设置室外对照(Ambient)、室内对照(CK,实时模拟室外环境)、高浓度CO_2(Ambient CO_2+200μmol/mol)、高浓度O_3(Ambient O_3的1.6倍)、高浓度CO_2+O_35个处理,研究大气组分变化对敏感水稻汕优63生长动态、物质生产及氮素吸收的影响。结果表明,室外对照和室内对照水稻的多数测定指标无显著差异。与CK相比,O_3处理使水稻生育中后期株高和分蘖数明显下降,且随时间推移降幅逐渐增加,最大降幅分别达21%和15%,但CO_2处理使水稻生育中后期株高和分蘖数明显增加,最大增幅分别为5%和18%,CO_2+O_3处理使水稻株高最大下降为7%,但对各期分蘖数没有影响。与CK相比,O_3处理使水稻成熟期叶片、茎鞘、稻穗和根系生物量大幅下降,使全株总生物量平均下降51%,CO_2处理对绿叶和黄叶生物量无显著影响,但使茎鞘、稻穗和根系生物量明显增加,使全株总生物量平均增加37%,CO_2+O_3处理对各器官和全株生物量均无显著影响。臭氧处理使生物量在叶片中的分配比例显著增加,而CO_2处理则表现相反,CO_2+O_3处理对水稻物质分配的影响小于单独的O_3处理。与CK相比,O_3处理使水稻抽穗期植株含氮率平均增加29%,吸氮量下降31%,而CO_2处理或CO_2+O_3处理对地上部植株含氮率和吸氮量的影响均未达显著水平。试验结论,近地层臭氧浓度升高使水稻变矮、分蘖减少、生长受抑,但同步增加的二氧化碳浓度可明显缓减甚至抵消臭氧胁迫对汕优63生长发育的负效应。
Changes in atmospheric composition will greatly alter future rice production. In this study, a new closed-top chamber was used to investigate the effects of elevated CO2 and O3 on growth, dry matter production, and nitrogen （N） uptake. A three-line indica hybrid rice cultivar, Shanyou 63, was grown under five gas treatments ： ambient, CK （ reahime simulation of ambient conditions）, elevated [ O3 ] （60% higher than the ambient O3 concentration）, elevated [ CO2 ] （200 μmol/mol above ambient CO2 concentration）, and combined elevation of [ CO2＋O3 ]. For most of the measured parameters, there was no statistically significant difference between ambient and CK plants. Relative to the CK, elevated [ O3 ] was significantly related to decreased plant height and tiller number within the middle and late growth stages, with the largest decreases （21% for plant height and 15% for tiller number） detected at the final measurements： Elevated [ CO2 ] showed opposite trends, with the largest ozone-induced increases of 5% and 18% for plant height and tiller number, respectively. Elevated [ CO2＋O3] decreased plant height （largest reduction： 7%）, but did not alter tiller number. Compared with the CK, elevated [ O3 ] greatly decreased the biomass of leaves, stems, panicles, and roots at grain maturity, with 51% reduction recorded for total biomass. Elevated [ CO2 ] did not change the biomass of green and senescent leaves, but increased the biomass of stems, panicles, roots, and thus total biomass （37%）. There was no significant effect of elevated [CO2＋O3 ] on total biomass and its components. Dry matter distribution in leaves significantly increased with elevated [ O3 ], while opposite trends were observed with elevated [ CO2 ]. The magnitude of the combined [ CO2＋O3 ] effect on dry matter distribution was smaller than that of the solo [ O3 ] treatment. Elevated [ O3 ] increased shoot N concentration by 29%, and it decreased shoot N uptake by 31% at heading stage. Elevated [ CO2 ] and [ CO2＋O3 ] had no significant effect on aboveground N concentration and uptake. The above results suggested that the projected increase of surface ozone concentration will inhibit plant elongation, tiller production, and growth of hybrid Shanyou 63. The concurrent increases in [ CO2＋O3 ] either ameliorated or negated the detrimental effects of O3 stress on growth and development.
出处
《生态学报》
CAS
CSCD
北大核心
2015年第24期8128-8138,共11页
Acta Ecologica Sinica
基金
国家自然科学基金项目(31371563,31171460,31071359)
江苏省高校自然科学重大基础研究项(11KJA210003)
江苏高校优秀科技创新团队和江苏省高校优势学科建设工程项目资助
关键词
汕优63
人工气候室
二氧化碳
臭氧
生长发育
Shanyou 63
Closed-top chamber
Carbon dioxide
Ozone
Growth and development
