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作 者 ：孙晓方;任明迅;王钢;檀根甲;何家庆;黄训端;平江;葛结林

期 刊 ：武汉植物学研究 2008年 26卷 6期 页码：620-626

关键词：加拿大一枝黄花；光强；光合特性；克隆生长；表型可塑性；

Keywords:Solidago canadensis, Light intensity, Photosynthetic characteristics, Clonal growth, Phenotypic plasticity,

摘 要 ：对入侵植物加拿大一枝黄花(Solidago canadensis)在不同光强下的光合作用特性和克隆生长规律进行了研究。结果表明:(1)随着光强的降低,加拿大一枝黄花叶片净光合速率(P_n)、最大净光合速率(P_max)、光饱和点(LSP)、光补偿点(LCP)和表观量子效率(AQY)均下降,但P_n、P_max和LSP在高光照(lx:50 000)和中光照(lx:30 000)下差异不显著;(2)虽然生长在低、弱光照条件下的加拿大一枝黄花克隆生长明显受到抑制,克隆分株数(<2)、根茎数(<4)、分枝强度(<6)、根茎平均长度(<17 cm)、根茎直径(<0.33 cm)均显著降低,但克隆生长主要指标[克隆分株数(>15)、根茎数(>7)、分枝强度(>30)、根茎平均长度(>64 cm)、根茎直径(>0.59 cm)]在高、中光照条件下差异不显著。研究结果证明,高光照生境对加拿大一枝黄花的生长最为有利,虽然在弱光下光合和克隆生长受到一定抑制,但能通过较强的可塑性适应不同强度的光照条件,这可能是其广泛成功入侵的一个原因。

Abstract:Understanding the eco-physiology and growth patterns of invasive plant is crucial to identify its invasive mechanism and formulate effective management strategy.Solidago canadensis,a noxious invasive plant throughout world including China,is able to invade into many habitats of various light intensities.To explore the invasive mechanism of this plant invader,we study its photosynthetic physiology and patterns of clonal growth in habitats of different light gradients.The results showed:that(1)The net photosynthetic rates,maximum net photosynthetic rates,light compensation point,light saturation point,and apparent quantum yield of S.canadensis declined with the decrease of light intensity.There was no significant differences among the photosynthetic physiological traits under highest light intensity(lx:50 000)and moderate light intensity(lx:30 000),while difference between moderate and low light intensities(lx:10 000),and between low light intensity and weak light intensity(lx:2 500)were significant.(2)The clonal growth(number of ramets(>15),number(>7)and length(>64 cm)of rhizome,diameter of rhizome(>0.59 cm))of S.canadensis under the high and moderate light intensities showed no significant differences,normally with more than 15 ramets and with very long rhizomes(usually >50cm).However,plants cultured under low and weak light intensities showed significantly decreased clonal growth,normally with only 2 ramets and much shorter(<17 cm)rhizomes.The plants in different light intensities also showed a different clonal architecture because the rhizomes changed greatly,plants in high and moderate light intensities had very long rhizomes and the plants were guerilla strategist,while the plants in low and weak light intensities had very short rhizomes and the plants grew in phalanx forms.This different clonal architecture greatly enhanced the plants’ability to adapt to various habitats of different levels of resources such as light intensity.Collectively,the results showed that S.canadensis was well adapted to habitats with high light intensity,and clonal growth and photosynthesis was inhibited under low and weak light intensities.However,its photosynthetic characters and clonal growth can maintained via plastic responses to a broad range of light intensities,which possibly facilitate its successful invasions in various habitats,including cropland,roadside and forest edge.

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