摘要
以2年生的田间‘金矮生’苹果为试材,对不同季节苹果叶片光合速率、气孔导度的日变化研究表明,“单峰型”是田间苹果叶片Pn日变化的主要类型,一天中Pn在上午8-10时达最大值,之后逐渐降低。中午过大的水蒸汽压亏缺和过高的叶温是引起Pn降低的主要因素。在大多数情况下,Gs与Pn的日变化趋势一致,但细胞间隙CO_2浓度、气孔限制值一天中变化不大,气孔对光合作用的限制较小,Pn的日变化主要取决于叶肉光合能力的变化。
2-year-old field-grown'Gold Spur'trees were used to study the diurnal changes of leaf photosynthetic rate ( Pn ) , stomatal conductance ( G s ) in different seasons. It was found that one-peak pattern was the main one of Pn diurnal changes in leaves of apple trees grown in the field. Pn reached a maximum at 8:00-10:00 A.M., then gradually decreased. The Pn decline was mainly cacsed by large leaf-air vapour pressure difference and high leaf temperature at noon, In most cases, Gs. and Pn showed similar diurnal changes,but the leaf internal CO_2 concentration and stomatal limitation value maintained relatively unchanged during daytime. The stomata had a little limitation on photosynthesis.The Pn diurnal change in apple leaves was mainly controlled by the mesophyll photosynthetic capacity.
出处
《园艺学报》
CAS
CSCD
北大核心
1992年第2期111-116,共6页
Acta Horticulturae Sinica
关键词
苹果
光合速率
气孔导度
日变化
Apple
Photosynthetic rate
Stomatal conductance
Diurnal changes
