不同生态型芦苇种群对盐胁迫的生长和光合特性

土壤盐渍化是影响我国土壤利用效率的主要因素之一,芦苇是改良土壤盐渍化的良好实验材料,但芦苇有着多种的生态型,比较各生态型芦苇的耐盐差异成为亟待解决的问题。通过设置淡水(0.00%)与加盐(质量浓度2.00%)处理控制实验,测量芦苇的生长指标和光合指标,比较河口型芦苇与内陆型芦苇耐盐性,寻找合适生态型的芦苇作为改良土壤盐渍化的生物材料。在实验中,与淡水条件相比,加盐(2.00%)处理条件下,河口型芦苇和内陆型芦苇的株高(height)、蒸腾速率(E)均显著性下降,但是两种生态型的芦苇的水分利用效率(WUE)明显提高;河口型的芦苇相对生长速率(RGR)和气孔导度(Gs)都明显高于内陆型芦苇。在淡水环境中,河口型芦苇的相对生长速率(RGR)和净光合速率(A)都显著性地高于内陆型芦苇。结果表明两种生态型的芦苇在进化过程中存在一定程度上的分化,盐胁迫会抑制两种芦苇的生长,两种生态型芦苇的相对生长速率和气孔导度在盐胁迫下出现明显地差异,表明两种生态型的芦苇对盐度的响应机制有所差异。相比于内陆型芦苇,河口型芦苇有着更强的耐盐性,内陆型及河口型芦苇的表型性状差异主要是由于其原生境的差异所决定的。

Different adaptions of physiological ecology between estuarine and landlocked reeds in different salinities

Soil salinization is one of the main factors affecting soil use efficiency in China. Phragmites australis is a good experimental material for improving soil salinization. Phragmites australis has a variety of ecotypes, and determination of salt tolerance differences among ecotypes of Phragmites australis is an urgent problem to be solved. By setting up freshwater and saltwater treatments, and measuring the growth index and photosynthetic index of Phragmites australis in both, an experiment was conducted to compare the salinity of estuarine reeds and landlocked reeds, and to find biological material to combat soil salinization. Compared with the freshwater treatment, the height and transpiration rate (E) of landlocked reeds significantly decreased under the condition of salt addition, but the water use efficiency (WUE) of both ecotypes significantly increased. The relative growth rate (RGR) and stomatal conductance (Gs) of estuarine reeds were significantly higher than those of inland reeds. In the freshwater environment, the relative growth rate (RGR) and net photosynthetic rate (A) of estuarine reeds were significantly higher than those of inland reeds. The results showed that there was a certain degree of differentiation between the two ecotypes of reeds during the evolutionary process and that salt stress inhibited the growth of both ecotypes. The relative growth rate (RGR) and stomatal conductance (Gs) of the two ecotypes of reed showed significant differences under salt stress, which indicates that the responses of the two ecotypes to salinity are different. In comparison to inland reeds, estuarine reeds are more resistant to salt stress. The differences in phenotypic traits of inland and estuarine reeds are mainly determined by the differences in their in situ habitats.