四种生态型芦苇叶中离子分布对生境的生理适应(英文)

Physiological Adaptation of Habitat by Ion Distribution in the Leaves of Four Ecotypes of Reed (Phragmites australis)

采用X射线微区分析技术 ,测定了 4种生态型芦苇 (Phragmitesaustralis (CaV .)Trin .exSteud .)叶的表皮泡状细胞、叶肉细胞和叶脉维管束鞘细胞离子的含量。结果表明 :沼泽芦苇的鞘细胞内 ,K+、Na+、Ca2 +、Mg2 +和Cl-分布均较叶肉细胞和泡状细胞高。沙丘芦苇的泡状细胞中Ca2 +分布较叶肉细胞和鞘细胞高 ,而Mg2 +在其叶肉细胞 ,以及K+、Na+和Cl- 在其鞘细胞内分布均较高。在轻度盐化草甸芦苇的叶肉细胞内分布较多的Na+和Mg2 +,而在鞘细胞内K+、Ca2 +和Cl- 的分布均较叶肉细胞和泡状细胞为高。重度盐化草甸芦苇的泡状细胞内Na+和Mg2 +的分布较多 ;同样 ,在叶肉细胞中K+、Ca2 +和Cl- 的分布也较多。最后 ,讨论了上述各种离子在不同生态型芦苇叶内分布的状况 ,以及与其环境适应的生理意义。

The ion levels in the epidermal bulliform cells of epidermis, mesophyll cells and cells of the vascular bundle sheath of four ecotypes of reed (Phragmites australis (Cav.) Trin. ex Steud.) were determined by means of X_ray microanalysis. The results indicated that higher K +, Na +, Ca 2+ , Mg 2+ and Cl - were distributed in the vascular bundle sheath cells than in mesophyll cells and epidermal bulliform cells of the swamp ecotype. Higher Ca 2+ was found in the bulliform cells than in mesophyll cells and vascular bundle sheath cells, higher Mg 2+ in the mesophyll cells and higher K +, Na + and Cl - in the vascular bundle sheath cells of the dune ecotype. Higher Na + and Mg 2+ was determined in the mesophyll cells than in the bulliform cells and vascular bundle sheath cells, and higher K +, Ca 2+ and Cl - in the vascular bundle sheath cells of the light salt meadow ecotype. In the heavy salt meadow ecotype, higher Na + and Mg 2+ were accumulated in the bulliform cells than in mesophyll cells and vascular bundle sheath cells, but higher K +, Ca 2+ and Cl - in the mesophyll cells. Furthermore, the distributional conditions of the above five ions in leaf cells of the four ecotypes and their significance in the physiological adaptation of reed to habitat were discussed in detail.