伊乐藻光合能力对三种生态因子的响应

Responses of the Photosynthetic Capacity of Elodea nuttallii to Three Ecological Factors

为了解外来种伊乐藻的生态适应性,通过测定其光合产氧量的方法,研究了其光合能力对温度、光照强度和pH3种生态因子的响应。结果表明:在温度和光照范围分别为10～35℃和1×103～5.3×103lx的条件下,伊乐藻光合净产氧量和总产氧量都与温度和光照呈正相关,随温度和光照强度的增加,光合净产氧量和总产氧量呈增加趋势,对不同的温度和光照组合均有很强的适应性;在5300lx条件下,30℃时总产氧量最高,为1.814mg/(L.h.g),净产氧量也最高,为1.47mg/(L.h.g);在30℃时,5300lx光照强度下其总产氧量和净产氧量均最高,光合能力强,但未达光饱和点;最低光强度条件下未达光补偿点。在pH5～9的5种梯度内,适宜pH范围为5～7,pH为6时生长最佳。伊乐藻光合能力对3种生态因子响应的基本生理生态学特征为:对光照强度和温度的适应性较强,在较强的光照、较高的温度和中性略偏酸的水环境中生长较好。

In order to know the ecological adaptability of alien species Elodea nuttallii,the responses of photosynthesis capacity of Elodea nuttallii to three main ecological factors,as light intensity,temperature and pH,were studied by measuring the photosynthetic oxygen production.The results showed that with the temperature and illumination 10-35℃ and 1 × 103-5.3 × 103 lx conditions,the net and gross photosynthetic oxygen production of Elodea nuttallii showed a positive correlation with the temperature and illumination.With the increasing of temperature and light intensity,the net and gross photosynthetic oxygen production increased;it showed very strong adaptability to different temperature and illumination combinations.In the same light condition,at about 30℃ the gross production of oxygen was,the most 1.814 mg/（L·h·g）,net oxygen production was also the most 1.47 mg/（L·h·g）.With the same temperature,5300lx light intensity,the gross and net photosynthetic oxygen production were the most,photosynthetic capability was strong,but not reached the light saturation point;in the minimum light intensity conditions,it also didn＇t reach its light compensation point;among the range pH 5-9,the suitable pH values ranged from 5.0 to 7.0,and the optimum was pH 6.0.The basic physiological and ecological characteristics of which the response of Elodea nuttallii photosynthetic capacity to three ecological factors were as the follows：it had strong adaptability to the light intensity and temperature.it grew well in the strong light intensity,higher temperature and meta-acid water environment.