芦苇、互花米草的生长和繁殖对盐分胁迫的响应  

Responses of growth and sexual reproduction of Phragmites australis and Spartina alterniflora to salinity stress

作　　者：肖燕[1] 汤俊兵[1] 安树青[1] 

机构地区：[1]南京大学生命科学学院湿地生态研究所,南京210093

出　　处：《生态学杂志》2011年第2期267-272,共6页Chinese Journal of Ecology

基　　金：国家教育部博士点基金项目(20070284022);国家林业局公益项目(200804005)资助

摘　　要：对2种海滨植物——土著种芦苇(Phragmites australis)和外来种互花米草(Sparti-na alterniflora)在淡水、中盐度(15‰)和高盐度(30‰)环境下生长和有性繁殖特征及其年际动态进行了研究,以期探索海滨植物对盐分胁迫的适应机制。结果表明:2年中各盐度处理下互花米草地上部分生物量均高于芦苇,芦苇和互花米草地上部分生物量、株高和分蘖数均随着盐度的升高而显著下降。芦苇第1年没有开花;第2年,只有淡水和中盐度处理下的芦苇开花。各盐分梯度下,第1年互花米草的开花株数没有显著差异,但花序重量在高盐度条件下显著下降;第2年高盐胁迫仍然抑制了互花米草的繁殖。第1年各处理下的芦苇株高均低于互花米草,但第2年淡水和中盐环境中的芦苇株高高于互花米草。除了高盐处理下的芦苇,第2年这2种植物地上部分生物量、株高、开花株数、花序重量显著高于第1年。与芦苇相比,互花米草表现出较高的生长能力和耐盐能力;2种植物的生长和繁殖的能力随着定居时间的增加而提高,但高盐胁迫抑制了芦苇第2年的增长;芦苇第2年在淡水和中盐度条件下表现出株高上的优势。Two coastal plants,native Phragmites australis and exotic Spartina alterniflora,were grown in fresh water and the waters with salinity 15‰ and 30‰ to study their yearly dynamics of growth and sexual reproduction characteristics,aimed to explore the adaptation strategies of the two plants in response to increasing water salinity. Throughout the two-year experimental period,the aboveground biomass of S. alterniflora in all treatments was higher than that of P. australis. The aboveground biomass,shoot height,and ramet number of S. alterniflora and P. australis decreased with increasing water salinity. P. australis did not flower in the first year,but flowered in freshwater and medium salinity water in the second year. In the first year,the number of flowering ramets of S. alterniflora showed no difference among all treatments,but the inflorescence biomass decreased significantly in the water with high salinity. In the following year,the sexual reproduction of S. alterniflora was still inhibited by high salinity. The P. australis grown in fresh water and medium salinity water was taller than the S. alterniflora grown in the same waters in the second year,though the plant height of P. australis was shorter than that of S. alterniflora in the first year. Except P. australis in high salinity treatment,the aboveground biomass,shoot height,flowering ramet number,and inflorescence biomass of the two plants were higher in the second year than in the first year. Compared with P. australis,S. alterniflora had a relatively stronger growth ability and stronger tolerance to water salinity. The growth and sexual reproduction of the two plants increased with the time after establishment,but high salinity inhibited the increments for P. australis. In freshwater and medium salinity water,P. australis showed an advantage of shoot height in the second year.

关 键 词：芦苇 互花米草 海滨植物 入侵 盐胁迫 生长 有性繁殖 

分 类 号：Q948[生物学—植物学]