Responds on the Growth of Interaction Competition Between Macro-Algae (Ulva Pertusa Kjellman) and Micro-Algae (Platymonas Helgolandica Kylin Var. Tsingtaoensis) Population Under the Enhanced UV-B Radi

In this study, using ulva pertusa kjellman (hereafter abbreviated as "Up") and Platymonas helgolandica Kylin var. tsingtaoensis (hereafter abbreviated as "Ph") as the materials we investigated the effects of UV-B radiation on interaction of macro-algae and micro-algae. Our results demonstrated that: (a) In normal mixed culture, Ph inhibited the growth of Up and this inhibition was more significant when increasing original inoculation density. However, Up inhibited the growth of Ps in early phase (before the 6^th day) and stimulated the growth in later phase (after the 9^th day), (b) Under the UV-B radiation treatment, Ph inhibited the growth of Up and this inhibition was more significant as the original inoculation density of Ph increased in mixing culture. The growth of Ph was neither stimulated nor inhibited under lower does of UV-B radiation treatment and lower original inoculation density of Ph, however, it was inhibited more significantly when increasing both the inoculation density and the doses of UV-B radiation. It is interesting to note that comparing with that in mixed culture, the growth of both Ph and Up was inhibited under the UV-B radiation treatment.