Effects of Root-Zone Temperature on Antioxidative Enzyme Activities, Mineral Contents, and Growth of Grafted Watermelon Plug Seedlings

근권온도가 수박성형묘의 생육, 무기성분 흡수 및 항산화 효소활성에 미치는 영향

This study was carried out to examine the effect of root-zone temperatures on seedling growth, mineral contents and antioxidative enzyme activities of grafted watermelon. The grafted watermelon seedlings were grown in greenhouse bed for 20 days at root-zone day temperatures of 10, 15, $25^{\circ}C$ while night temperature was maintained at $10^{\circ}C$. Growth such as shoot height, leaf length, leaf number, stem diameter, and fresh and dry weights increased as increasing root-zone temperatures, and leaf area with $25^{\circ}C$($52.79mm^2$) was two times that of control($21.50mm^2$). As increasing the root-zone temperatures, Mn, Ca, Fe contents increased, K, P, Mg were non significant, and Na decreased. The activities of ascorbate peroxidase(APX) and guaiacol peroxidase(GPX) known as antioxidative enzyme were higher at $10^{\circ}C$ than $25^{\circ}C$.

저면관비 육묘재배시 근권온도의 차이가 접목수박묘의 생육, 양분흡수 그리고 효소활성에 미치는 영향을 알아보고자 실험을 수행하였다. 근권온도 처리는 각각 무가온, $10^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$로 처리하였으며, 야간 최저온도는 $10^{\circ}C$로 유지하였다. 생육 20일후의 초장, 엽장, 엽수, 경경, 그리고 생체중 및 건물중은 온도가 증가함에 따라 증가하였으며, 엽면적에서는 무가온($21.50mm^2$)에 비해 $25^{\circ}C$에서 $52.79mm^2$으로 2배 이상의 증가를 나타내었다. Mn, Ca, Mg, Fe는 온도가 증가함에 따라 흡수량이 증가하였고, K, P, Mg는 유의성이 없었으며 Na는 역으로 감소하였다. Stress저항성 항산화효소인 ascorbate peroxidase(APX)와 guaiacol peroxidase(GPX)의 활성은 온도가 $10^{\circ}C$에서 가장 높은 활성을 보였으며 온도가 높아질수록 감소하였다.