Phenotypic comparisons of Phragmites australis population with the different soil salinities

초록

Phragmites australis (common reed) is widely distributed in the various habitats from salt marshes to freshwater meadows. The objective of this study is to compare morphological characteristics and chromosome numbers of two P. australis populations with the different soil salinities in a salt marsh of the western coastal area of Korea. The high salt habitat showed higher electric conductivity, more water content, and lower available phosphorous of soils than the low salt habitat. The P. australis population of the low salt habitat had higher and thicker shoots, larger leaves, longer inflorescences, and thicker rhizomes than that of the high salt habitat. The density of shoots at the low salt habitat was smaller than that at the high salt habitat. At the low salt habitat the biomasses of shoot, inflorescence, rhizome and root were much larger than those at the high salt habitat. Above-ground/below-ground ratio and inflorescence/total ratio of biomasses were not significantly different between the both habitats. The concentrations of nitrogen and phosphorus of leaves were higher at the low salt habitat than at the high salt habitat. These data suggest that the P. australis populations display the phenotypic differences of morphological characteristics according to the salt concentration of soils. From the results of ploidy analysis by flow cytometry, only tetraploid (4x, with x=12) was found at both habitat. Therefore, difference of morphological characteristics of P. australis with the different soil salinities was due to the genotypic variation beyond polyploidy level or the phenotypic acclimation environment.