High-temperature tolerance of a tropical tree, Ficus insipida: methodological reassessment and climate change considerations
High-temperature tolerance of a tropical tree, Ficus insipida: methodological reassessment and climate change considerations
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DOI：
10.1071/fp10034
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发表时间：
2010-01-01
影响因子：
3
通讯作者：
Virgo, Aurelio
中科院分区：
文献类型：
--
作者：
Heinrich Krause, G.;Winter, Klaus;Virgo, Aurelio
针对全球气候变暖的影响，研究了新热带拓荒树榕的耐热性。他很坚决。在室温和高温下培养的成熟树和幼苗的晒叶切片被加热到42-53摄氏度。，也进行了研究。重新评估了基于热诱导初始荧光发射F-o上升和可变荧光与最大荧光之比F-v/F-m下降的广泛使用的叶绿素a荧光方法。热处理24 h后测定的F-v/F-m是评价致死性组织损伤致死温度最合适的荧光参数。当热处理后立即记录F-o和F-v/F-m时，热耐受性被低估。耐温极限在50 ~ 53℃之间，仅比原位测得的叶片峰值温度高几度。在高温下生长的植物的耐热性没有季节变化，耐热性只有边际增加，这表明进一步热驯化的能力很小。在51 ~ 53℃的高温胁迫下，完整盆栽幼苗的叶片受到不可逆的损伤，但在培养后植株存活并长出了新叶。
In view of anthropogenic global warming, heat tolerance of a neotropical pioneer tree, Ficus insipida Willd., was determined. Sections of sun leaves from a mature tree and from seedlings cultivated at ambient and elevated temperatures were heated to 42-53 degrees C. Leaves from a late-successional tree species, Virola sebifera Aubl., were also studied. Widely used chlorophyll a fluorescence methods based on heat-induced rise of initial fluorescence emission, F-o, and decrease in the ratio of variable to maximum fluorescence, F-v/F-m, were reassessed. F-v/F-m determined 24 h after heat treatment was the fluorescence parameter most suitable to assess the lethal temperature causing permanent tissue damage. Thermo-tolerance was underestimated when F-o and F-v/F-m were recorded immediately after the heat treatment. The limit of thermo-tolerance was between 50 and 53 degrees C, only a few degrees C above peak leaf temperatures measured in situ. The absence of seasonal changes in thermo-tolerance and only marginal increases in thermo-tolerance of plants grown under elevated temperatures suggest little capacity for further heat acclimation. Heat-stress experiments with intact potted seedlings also revealed irreversible leaf damage at 51-53 degrees C, but plants survived and developed new leaves during post-culture.