Morphological and photosynthetic physiological characteristics of Saussurea salsa in response to flooding in salt marshes of Xiao Sugan Lake, Gansu, China
Morphological and photosynthetic physiological characteristics of Saussurea salsa in response to flooding in salt marshes of Xiao Sugan Lake, Gansu, China
复制标题
DOI：
10.17521/cjpe.2019.0132
复制
发表时间：
2019-08-01
影响因子：
--
通讯作者：
Ma Jun-Yi
中科院分区：
文献类型：
--
作者：
Li Qun;Zhao Cheng-Zhang;Ma Jun-Yi
盐沼湿地植物叶片功能性状对淹水的响应分析, 有助于探究植物叶片可塑性机制与光合生理特征间的内在关联性, 对深入理解盐沼湿地植物的生境抗逆性策略具有重要意义。为探讨盐地风毛菊（Saussurea salsa）叶片功能性状对淹水的响应，以甘肃省小苏干湖候鸟自然保护区（北纬39.22 ° ~ 39.35 °，东经94.45 ° ~ 94.59 °）为研究点，采用盆栽试验和田间试验相结合的方法，研究了盐地风毛菊（Saussurea salsa）叶片功能性状对淹水的响应。在小苏干河北岸低洼地带，从湖岸边缘到常年潮水线末端选取一个样带。根据小苏干湖历年洪水涨退标志水位，测算了盐沼湿地的内涝持续时间。根据水淹时间的长短，将样带划分为3个样地：低水淹区（水淹时间为30-90 d）、中水淹区（水淹时间为90-150 d）和深水淹区（水淹时间为150-210 d）。S的6个子地块（2 m × 2 m）。从三块地中的每一块地选择色拉，总共18个子地。调查了黄胸跳甲的群落特征和种群特征。盐渍土、土壤水分和土壤电导率（EC）。每个亚区选择6株植物进行光合作用和叶绿素荧光测量。分别从6个S.结果表明，盐生植物的叶面积、叶厚、干重和叶绿素含量均比野生植物高; salsa改变了S.结果表明：随着淹水时间的延长，盐地碱蓬叶片形态和光合作用发生了明显的变化。在低洪泛区，S.盐地碱蓬为肉质小叶型，比叶面积（SLA）小，光合系统II（PSII）的光化学有效量子产率（Y（II））高，调节能量耗散的量子产率（Y（NPQ））低。然而，S.与低涝区相比，深涝区生长的莎莎在叶片形态和光合作用方面采取了完全相反的协变策略。结果表明，在3个样地中，SLA与Y（II）、光化学猝灭（QP）和Y（NPQ）均呈显著正相关，非调控能量耗散量子产额（Y（NO））与叶绿素a含量（C-a）和叶绿素b含量（C-b）均呈显著正相关.受小苏干湖水淹区静水时空演变格局的影响，S.通过改变叶面积、叶厚和SLA等形态特征，适时调节Y（NPQ）和Y（II）等光合特性，达到光合碳收支的平衡。盐地风毛菊对水盐异质性具有较强的耐受性，反映了极端环境下盐沼湿地植物叶片的可塑性和抗性机制。
Aims The response of plant leaf functional traits to flooding in salt marshes is not only helpful in exploring the internal correlation between leaf plasticity mechanism and photosynthetic characteristics, but also of vital significance for gaining a better understanding on the stress resistance strategies of plants in salt marsh wetlands. The aim of this study is to investigate the responses of leaf functional traits of Saussurea salsa to flooding with the changes of water-logging durations.Methods The research site was located in provincial migratory bird nature reserve in Xiao Sugan Lake, Gansu Province, China (39.22 degrees-39.35 degrees N, 94.45 degrees-94.59 degrees E). A sample belt was selected from the edge of the lakeshore to the end of the perennial tidewater line in the low-lying area along the north side of Xiao Sugan River. The duration of water-logging in the salt marsh wetland was measured base on the water level marked by the flood rise and retreat marks in Xiao Sugan Lake over the years. The sample belt was divided into 3 plots according to the water-logging duration: low flooding area (water-logging duration: 30-90 days); medium flooding area (water-logging duration: 90-150 days); and deep flooding area (water-logging duration: 150-210 days). Six subplots (2 m x 2 m) of S. salsa were selected from each of the three plots for a total of 18 subplots. We investigated community characteristics and population traits of S. salsa, soil moisture and soil electrical conductivity (EC). Six plants per subplot were selected for photosynthesis and chlorophyll fluorescence measurements. Foliar samples collected from each of the six S. salsa were taken to the laboratory for measurements of leaf traits (leaf area, thickness, dry mass and chlorophyll content).Important findings The results showed that S. salsa changed the covariation strategy of S. salsa foliar morphology and photosynthesis with the extension of water-logging duration. In the low flooding area, S. salsa adopted fleshy lobular pattern with small specific leaf area (SLA), high effective quantum yield of photosynthetic system II (PSII) photochemistry in light (Y(II)) and low quantum yield of regulated energy dissipation (Y(NPQ)). However, S. salsa grew in the deep flooding area adopted completely opposite covariation strategy in foliar morphology and photosynthesis compared with those grew in the low flooding area. We observed a significant correlation between SLA and Y(II), photochemical quenching (QP), and Y(NPQ), as well as a significant positive correlation between the quantum yield of non-regulated energy dissipation (Y(NO)) and chlorophyll a content (C-a), chlorophyll b content (C-b) in all of the three plots. Under the influence of the spatio-temporal evolution pattern of still water in the flooded area of Xiao Sugan Lake, S. salsa population achieved the balance of the photosynthetic carbon budget by changing the morphological characteristics of leaves, such as leaf area, leaf thickness and SLA, timely adjusting the photosynthetic characteristics, such as Y(NPQ) and Y(II). Saussurea salsa showed strong tolerance to water and salt heterogeneity, reflecting the leaf plasticity and resistance mechanism of salt marsh wetland plant under extreme environments.