光照条件对‘寒富’苹果叶片结构和光合特性的影响

以‘寒富’苹果为试材，利用光学显微镜技术和气体交换等方法，研究了光照条件对盆栽和田间条件下‘寒富’苹果叶片结构和光合特性的影响.结果表明： 同种栽培方式下，与全光照条件相比，遮阴环境下‘寒富’苹果叶片的栅栏组织、海绵组织以及叶片总厚度均降低，其中，栅栏组织分别降低34.5%(盆栽)和25.0%(大田)，叶片总厚度分别降低27.1%(盆栽)和18.3%(大田)；遮阴环境下大田‘寒富’苹果叶片的光补偿点(LCP)最低，为(30.8±1.3） μmol·m^-2·s^-1，全光照比遮阴环境下叶片饱和光强分别高22.7%(盆栽)和48.2%(大田)；盆栽不同光照环境下叶片对强光的适应能力不同，突然转入强光下，达到最大光合速率15.4 μmol·m^-2·s^-1(盆栽全光照)和12.7 μmol·m^-2·s^-1(盆栽遮阴)的光合启动时间不同，分别为23和33 min.表明长期遮阴影响‘寒富’苹果叶片质量及光合能力.

Effects of light condition on structure and photosynthetic characteristics of leaves in ‘Hanfu’ apple.

By using microscope technique and gas exchange method, the effects of light conditions on structure and photosynthetic characteristics of the leaves were studied with potted and fielded ‘Hanfu’ apple as materials. The results showed that the palisade tissue, spongy tissue and the total leaf thickness of ‘Hanfu’ apple was declined under the weak light environment, the palisade tissue were declined by 34.5% (pot) and 25.0% (field), and the total leaf thickness were declined by 27.1% (pot) and 18.3% (field). The light compensation point (LCP) of the field shading leaves was lowest (30.8±1.3 μmol·m^-2·s^-1), the saturation point (LSP) in full light was 22.7% (pot) and 48.2% (field) higher than in shading, respectively. The adaptability of the potted ‘Hanfu’ apple leaves built under different light conditions had different resistivity after exposing to high light, the startup time of maximum photosynthetic rates (15.4 μmol·m^-2·s^-1 in full light and 12.7 μmol·m^-2·s^-1 in shading) were different, which was 23 min and 33 min, respectively. Long time shading impacted on the quality and photosynthetic capacity of ‘Hanfu’ apple leaves.