[Stem and leaf photosynthesis of seven desert woody species and its influencing factors]

Ying Yong Sheng Tai Xue Bao. 2023 Oct;34(10):2637-2643. doi: 10.13287/j.1001-9332.202310.007.
[Article in Chinese]

Abstract

Stem photosynthesis widely presents in desert plants, which increases carbon uptake capacity. In this study, we measured the photosynthetic characteristics of leaves and stems in seven desert woody plants (Populus euphratica, Populus alba var. pyramidalis, Populus pruinose, Haloxylon ammodendron, Calligonum rubicundum, Calligonum caput-medusae, Ammopiptanthus mongolicus) in the same habitat, using a portable Li-6400XT photosynthesis system combined with P-Chamber. We analyzed stem photosynthetic rate and its relationship with leaf photosynthetic rate. We measured the stem functional traits, including water content, stem dry matter content, chlorophyll content, water potential, non-structure carbohydrate (NSC), etc., to find out the main affecting factors of stem photosynthesis. The results showed that stem photosynthetic rate of seven species ranged from 0.72 to 1.71 μmol·m-2·s-1, with the largest of P. pruinose and the smallest of H. ammodendron. Stem photosynthetic rate could offset CO2 of stem respiration by 57%-83%. Leaf photosynthetic rate of the seven sepceis ranged from 12.80 to 22.54 μmol·m-2·s-1, with H. ammodendron and A. mongolicus being lower than those of the other five species. There was a significant positive correlation between leaf photosynthetic rate and stem photosynthetic rate. Stem water use efficiency was 2.2-7.7 times of the leaf. Chlorophyll content, NSC, stem respiration rate, and leaf photosynthetic rate were the main factors affecting stem photosynthesis.

枝干光合作用广泛存在于荒漠生态系统的木本植物中,增加了荒漠植物固碳能力。本研究以同一生境下胡杨、新疆杨、灰杨、梭梭红果沙拐枣、头状沙拐枣、沙冬青7种荒漠木本植物为对象,采用Li-6400XT便携式光合仪结合特制光合叶室(P-Chamber),监测不同植物的枝干、叶片光合特征,分析枝干光合速率及其与叶片光合的关系,并对枝干功能性状指标[含水量、干物质含量、叶绿素含量、水势、非结构碳水化合物(NSC)等]进行测定,确定影响枝干光合的主要因素。结果表明: 7种植物的枝干光合速率为0.72~1.71 μmol·m-2·s-1,其中最大的为灰杨,最小的为梭梭,可抵消枝干呼吸释放CO2的57%~83%;7种植物的叶片光合速率为12.80~22.54 μmol·m-2·s-1,其中梭梭和沙冬青叶片光合速率显著低于其他5种荒漠植物;枝干光合速率与叶片光合速率存在显著正相关关系;枝干水分利用效率是叶片水分利用效率的2.2~7.7倍;枝干叶绿素含量、NSC含量、枝干呼吸速率及叶片光合速率是影响枝干光合的主要因素。.

Keywords: desert plant; functional trait; leaf photosynthesis; stem photosynthesis; water use efficiency.

Publication types

  • English Abstract

MeSH terms

  • Carbohydrates
  • Chlorophyll
  • Fabaceae*
  • Photosynthesis*
  • Plant Leaves
  • Water

Substances

  • Chlorophyll
  • Carbohydrates
  • Water