短期CO2加富对凤梨光合作用及生长发育的影响

EFFECTS OF ELEVATED CO_2 CONCENTRATION ON PHOTOSYNTHSIS,GROWTH AND DEVELOPMENT OF THE BROMELIAD GUZMANIA

研究了CO2加富对丹尼斯凤梨（Gozmania‘Denise’）和吉利凤梨（Gozmania‘Cherry’）叶片光合速率、植株生长、开花和光合相关酶活性的影响。结果表明，处理30d期间，处理（600±40）、（900±40）μmolC02·mol^-1的净光合速率分别比同期对照增加了6．24％～31．91％和11．92％～41．48％；CO2加富下促进了叶片中可溶性糖和淀粉的积累，蒸腾速率和气孔导度下降，Rubisco活性增加，乙醇酸氧化酶活性则明显下降。（600±40）μmolC02·mol^-1处理下的株高、叶面积分别比同期对照下增加了6.94％～14．63％和1．66％～7．06％，而处理（900±40）μmolC02·mol^-1下分别增加了9．71％～20．85％和2．87％-11．62％；CO2加富下促进了干重和鲜重的积累。此外，CO2加富提前了吉利凤梨的花期。

Aims Our objective was to determine the effects of elevated CO2 concentration on photosynthetic characteristics, growth rate, flowering percentage and activity of photosynthetic enzyme in Guzmania ‘Denise＇ and Guzmania ‘Cherry＇. Methods We measured Pn, G5 and Tr under various growth conditions using the Li-6400 and used the data to calculate WUE （water use efficiency, WUE = Pn/Tr）. We determined chlorophyll and total soluble sugar levels by the method of Zhang ＆ Qu （2003）, starch content by the method of Xu et al. （1998） and rubisco and glycolic acid oxidase levels by the method of Ye et al. （1993）. Important findings Under two elevated CO2 concentrations, net photosynthetic rate increased by 6.24% - 31.91% and 11.92% -41.48% over plants grown in ambient CO2 concentration during 30 d. Elevated CO2 concentration caused a marked rise in soluble sugar and starch accumulation in leaves, but significantly reduced stomatal conductance and transpiration rate. In addition, Rubisco activity was increased, and glycolate oxidase activity obviously was decreased. Plant height and leaf area increased 6.94% - 14.63% and 1.66% -7.06% over plants grown in ambient CO2. There were 9.71% -20.85% and 2.87% - 11.62% increases for （900±40） μnol CO2·mo1^-1. Dry and fresh weights also increased with elevated CO2 concentration, as was flowering in Guzmnia ‘Cherry＇.