摘要
研究了低温胁迫对处于不同水分条件下柑桔光合作用的影响规律 .结果表明 ,低温胁迫对柑桔光合作用的影响与土壤水分状态关系密切 .对于正常供水的植株 ,低温能明显降低 Pn和 Gs.Ci/ Ca的比值升高表明低温主要抑制了叶肉细胞的光合能力 ;而适宜的根部温度能够提高受低温影响叶片的 Pn和 Gs,但从酶的大幅度增加可知 ,这是以散失大量水分为代价的 .而对于受水分胁迫的植株 ,一方面低温对 Pn的抑制作用不明显 .即水分胁迫使柑桔对低温胁迫变得不敏感 ;另一方面 ,与仅受低温影响的植株相比 ,提高根温反而使 Pn下降幅度更大 ,但 Gs和酶却增加 。
Effects of chilling on photosynthesis could be a function of soil moisture conditions. For plants with adequate water supply, Pn and Gs of their leaves were significantly reduced by chilling. This reduction, according to the rise in Ci/Ca ratio, was mostly attributable to chill induced depression of mesophyll photosynthetic capacity . Gs and Pn of leaves in chilled plants could be increased by raising the temperature of soil around the roots, which, however, increased E even more, so that water use efficiency decreased correspondingly. In other words, maintenance of an appropriate root temperature could improve the ability of shoots to tolerate chilling at the cost of large amount of water loss.On the other hand, inhibition of Pn by superimposed chilling on water stressed plants was insignificant. So it seemed apparent that water stressed plants were rendered less sensitive to impact of chilling. With water stressed plant in contrast to chilling plants, photosynthesis was inhibited rather than promoted by increase in root temperature whereas Gs and E were increased with consequent exacerbation of plant water deficit and more significant adverse effect of chilling on Pn.
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2001年第4期393-397,共5页
Journal of Zhejiang University:Agriculture and Life Sciences
