P-V 곡선법에 의한 참취와 수리취의 수분포텐셜 비교

초록

This study was carried out to establish a proper cultivation site and diagnose the drought-tolerance of Aster scaber and Synurus deltoides leaves by using Pressure-volume curves. In order to measure pressure-volume (P-V) curves, Aster scaber and Synurus deltoides were cut off above ground part and the tip of the cutting were placed in water, which was covered with a plastic bag. Samples were kept overnight (about 12 hours) in darkness at room temperature (20~25℃) to achieve maximal turgor (full saturation). The pressure in the chamber was gradually increased from 0.3MPa to 1.8MPa by nitrogen gas. After measured, leaf samples were dried at 80℃ for 48 hours and dry weight of each samples were determined. The result of the original bulk osmotic potential at maximum turgor Ψosat was lower -0.8 MPa in Aster scaber leaves than -0.7 MPa Synurus deltoides leaves. Also the osmotic potential at incipient plasmolysis Ψotlp in Aster scaber leave was -0.9 MPa. In contrast, the value of maximum bulk modulus of elasticity Emax of Aster scaber leaves were approximately two folds higher than that of Synurus deltoides leaves. The values of the relative water content at incipient plasmolysis RWCtlp are all above 90% showing that the function of osmoregulation is somewhat better, and Vo/DW, Vt/DW, Ns/DW of Synurus deltoides leaves were approximately 1~2 times higher than that of Aster scaber leaves. Thus, responses to water relations of Aster scaber and Synurus deltoides such as Ψosat, Ψotlp, Emax, ΨP, max, RWCtl were shown that the Aster scaber leaves was slightly higher drought- tolerance than Synurus deltoides leaves. However, in both of Aster scaber and Synurus deltoides, occurring incipient plasmolysis at the high water content, have a relatively lower drought-tolerance property indicating that growth of these plants are cultivated appropriate in high moisture soil sites.

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