摘要
天然杂交能够改变外来种对环境的适应性并提高外来种的入侵能力,甚至使其演变为入侵种。目前有研究发现,入侵植物三裂叶蟛蜞菊(Wedelia trilobata)与其本地同属近缘种蟛蜞菊(Wedelia chinensis)发生了杂交。为进一步探讨该杂交种在极端高温下的入侵潜力和扩散趋势,本研究从植物的生长、光合气体交换和叶绿素荧光特性3个方面对3种蟛蜞菊属植物在模拟极端高温(40/35℃处理28 d)下的生态适应性进行了比较。主要结果如下,(1)入侵种三裂叶蟛蜞菊对高温的耐受性最强,经高温处理后其净光合速率(P_n)、最大光化学效率(F_v/F_m)分别下降了52.23%和23.09%,其生物量(0.43 g?ind^(-1))显著高于本地蟛蜞菊(0.20 g?ind^(-1))。(2)本地蟛蜞菊对高温最为敏感,处理7 d后即表现出生长受到抑制,高温处理后P_n和F_v/F_m的降幅最大,分别为84.09%和68.05%。(3)杂交种对高温有一定的耐受性,处理14 d后开始表现出生长受到抑制,经高温处理后P_n和F_v/F_m分别下降74.43%和52.90%,其生物量(0.38 g?ind^(-1))介于入侵种三裂叶蟛蜞菊和本地种蟛蜞菊之间。以上结果表明,杂交种对高温的耐受能力介于两亲本之间。由于杂交种对高温的耐受性强于本地种,在未来极端暖事件频发的背景之下,杂交种的扩散可能会对本地蟛蜞菊种群的生存构成进一步的威胁,应当引起关注。
Natural hybridization has been proposed to increase the adaptation and aggressiveness of the new hybrid.A new hybridbetween the invasive Wedelia trilobata and its native congener,Wedelia chinensis was identified in a recent study.To explore theinvasive potential and development of this hybrid under extreme heat climate,the growth,gas exchange and chlorophyll fluorescencecharacters of these three Wedelia species under simulated extreme high temperature(40/35℃for28d)were examined in this study.The results were as follows:(1)The invasive W.trilobata had a greater tolerance to extreme heat.After28d high temperaturetreatment,its net photosynthetic rate(Pn)and the maximum photochemical efficiency(Fv/Fm)reduced by52.23%and23.09%respectively,and its biomass(0.43g?ind-1)was greater than that of the native W.chinensis(0.20g?ind-1).(2)The native W.chinensiswas sensitive to extreme high temperature.Its growth was inhibited after7d exposure to high temperature,and its Pn and Fv/Fmdecreased by84.09%and68.05%after28-day treatment.(3)The hybrid had a relatively higher tolerance to extreme heat than itsnative parent.Its performance was inhibited after14d high temperature treatment,and Pn and Fv/Fm decreased by74.43%and52.90%,its biomass(0.38g?ind-1)fell in between its two parent species after28d treatment.The heat tolerance of this hybrid fell inbetween its two parents.This study indicates that the native W.chinensis may be threatened by this hybrid under future extremeclimate scenarios due to their different tolerance to extreme heat.
作者
宋莉英
刘昭弟
李晓娜
肖雨沙
陈秀清
林益坤
SONG Liying;LIU Zhaodi;LI Xiaona;XIAO Yusha;CHEN Xiuqing;LIN Yikun(School of Life Science, Guangzhou University, Guangzhou 510006, China)
出处
《生态环境学报》
CSCD
北大核心
2017年第2期183-188,共6页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(31000187)
广东省高等学校优秀青年教师培养计划项目(Yq2013132)
广州市科技计划项目(201707010257)
广州大学大学生创新训练项目(201611078061)
关键词
蟛蜞菊属
杂交
极端高温
入侵力
wedelia
hybridization
extreme high temperature
invasiveness
