摘要
全球气候变化背景下,极端高温事件日益频繁,对植物的生长、存活造成严重威胁,准确评估植物的耐热性,对物种保育和适应性预测具有重要作用。木兰科是中国亚热带常绿阔叶林的标志类群,也是被子植物基部类群,具有重要的生态价值和演化生物学地位,然而目前对其耐热性尚缺乏了解。该研究以种植于同质园的23种木兰科植物为研究对象,利用叶绿素荧光技术研究了叶片光合系统的耐热性,同时测定了叶片形态性状,并基于这些物种在全球的分布地气候数据,分析了叶片光合系统耐热性与叶片形态及温度生态位的关系。发现木兰科植物光系统II最大光化学效率降低50%时的温度(T50)范围在46.1-56.7℃之间,且常绿物种的T50显著高于落叶物种。叶片形态方面,T50与叶面积显著正相关,与叶片厚度无显著相关关系。温度生态位方面,T50与年平均气温、最冷月最低气温呈显著正相关关系,但与最暖月最高气温无显著相关关系。T50具有较弱的系统发育信号,暗示T50受系统发育影响较小,受叶片形态与环境气候的影响较大。研究结果说明木兰科植物的叶片光合系统耐热性较强,但耐热性的气候适应可能并不受高温环境驱动,未来的高温事件对生活于更炎热地区的木兰科落叶植物威胁较大。
Aims The growth and survival of plants are being threatened by more frequent extreme high temperature events under global climate change.Therefore,for species conservation and adaptability prediction,it is essential to accurately evaluate the physiological heat tolerance across plant species.Magnoliaceae,as a typical basal angiosperm lineage,is one of the representative lineages in subtropical evergreen forests in China,with high ecological and evolutionary significance.However,the photosynthetic heat tolerance of Magnoliaceae plants is still unclear.Methods In this study,we used chlorophyll fluorescence method to exam the photosynthetic heat tolerance of 23 species of Magnolicaeae plants in a common garden.In order to analyze the relationships of photosynthetic heat tolerance with leaf morphology and temperature niche,for each species,we measured leaf morphological traits and calculated the temperature niche across their geographic distribution areas.Important findings The temperature that causes 50% decrease of the maximum photochemical quantum efficiency of photosystem II(T50)ranged from 46.1 to 56.7℃,with significantly higher T50 of evergreen species than that of deciduous species.For leaf morphology,T50 was positively correlated with the leaf area but was not significantly correlated with the leaf thickness.For temperature niches,T50 was positively correlated with mean annual air temperature and minimum air temperature of the coldest month but was not significantly correlated with maximum air temperature of the warmest month.A weak phylogenetic signal was found in T50,indicating that T50 was influenced by leaf morphology and environment conditions,rather than phylogeny.Our results suggested that photosynthetic heat tolerance of Magnoliaceae species were generally strong,but its adaptation may not be driven by high temperature environment.Future extreme high temperature events may severely threaten deciduous Magnoliaceae plants living in the warmer areas.
作者
叶洁泓
于成龙
卓少菲
陈新兰
杨科明
文印
刘慧
YE Jie-Hong;YU Cheng-Long;ZHUO Shao-Fei;CHEN Xin-Lan;YANG Ke-Ming;WEN Yin;LIU Hui(College of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642,China;Horticulture Center,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510520,China;South China National Botanical Garden,Guangzhou 510520,China;Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems,Guangdong Provincial Key Laboratory of Applied Botany,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2023年第10期1432-1440,共9页
Chinese Journal of Plant Ecology
基金
国家自然科学基金(32201286)。
关键词
光合系统耐热性
木兰科
高温胁迫
温度生态位
叶片形态
叶片习性
photosynthetic heat tolerance
Magnoliaceae
heat stress
temperature niche
leaf morphology
leaf habit
