| U．pinnatifida is one of the most important economic algaes in aisan countries.But U．pinnatifida cultivation are confronted with serious problems such as diseases,resource waste due to degeneration, quality declining and yield decrease. To slove theproblems and further develop U．pinnatifida cultivation industry, the primary study ofcompensation and its mechanism of U. pinnatifida under cultivation and study ofphysiology and biochemistry response of U．pinnatifida after mechanical damagewould play an important role.In this study, the sample was “Bei Hai Native spiece” U．pinnatifida cultivatedwidespreadly around Rong Cheng city. During2012.1-2012.5, we studied themorphological characterists, nutrient uptake rates, matter accumulation and allocation,pigments concentration and physiology and biochemistry response of U．pinnatifidaafter mechanical damage, the results were as follows（T1, T2, T3, T4representedtreatment groups which was treated in January, February, March, and Aprilrespectively, and C was the control group.）:1、Primary study of compensation mechanism of U. pinnatifida under cultivationafter mechanical damageT1exhibited over-compensation style, T2and T3exhibited equal-compensationstyle and T4performanced under-compensation pattern. When the growth phasestarted to slow and the fertility phase just did not begin yet was the best period ofexcision, and in the study the best period was when fertility phase just began, usuallyin January, and when blade length was about120cm. The growth mode after thallusexcision: the relative increase extent of different parts in T1was sporophyll>pinnateblade>midrib, the absolute increase amount of different parts in T1was pinnateblade>sporophyll>midrib; the growth stage was prolonged, T1was prolonged for3months and T2and T3was prolonged for only1months; T1’s fertility phase wasmoved up, which was attributed to fertility phase and growth phase occurring together, and the fertility of T2, T3were both promoted.Under the nutrient condition similar to the sampling area, T1’uptake rates ofNO3-N and PO4-P were both significantly higher than the control group.C and N contents changed in the same way during the study period. CN contentsin the blade decreased but in the sporophyll frist increased for fertility during earlyfertility stage and then declined. CN contents always decreased during the studyperiod in the apical part, but frist increased for compensation and then declined inboth middle and basical part in T1. CN contents always increased during the studyperiod in sporophyll in T1.Chl-a Chl-c and Carotenoids concentrations both in the basal part and the middlepart of T1were higher than those of the control during the early stage, but resultswere contrary in the apical part. The three pigments in the same part changedsimilarly and the concentration relation was Chl-a>Chl-c>Carotenoids. The resultsindicated pigment concentrations were promoted after thallus excision, and the risinglight intensity may be just one of the reasons why pigment concentrations werepromoted, not the main reason.2、Primary study of defense and respone of U．pinnatifida after mechanical damageH2O2and O2-concentrations changed similarly after mechanical damage,concentrations of treatment group significantly differred from control groupsignificantly after36h except120h; H2O2and O2-concentrations expanded quickly at36h and120h, separately, which meant that the defense system was motivated at36h.SOD activity of treatment group was lower significantly than that of controlgroup after12h, but SOD activity of control group was still high. The results indicatedthat mechanical damage could restrain SOD activity, but high SOD activity of bothtreatment group and control group suggested SOD as a long-term responsemechanism was always vital in the defense systemThe initial CAT activities were all low. CAT activity of treatment group wassignificantly higher than control group after12h till144h and expanded quickly at36h,120h respectively. There was negative CAT activity in both the treatment and controlgroups. These results declared that CAT activity was usually considerably low, but mechanical damage could induce CAT to highly performance in a short period. Boththe shortcoming of the experimental method and usual low activity of U．pinnatifidacould be the reasons why there were negative values.The initial POD activities were all low. There was significantly variance betweenthe treatment and the control group after36h except120h. But then POD activity ofthe treatment group was significantly higher than that of the control except120h.There was negative POD activity. These results may occurred due to the same reasonsas CAT.AsA initial concentrations both maintenanced about20mg/gprot and GSH showedin the same way. Then AsA content of treatment kelps went up significantly and washigher than that of control kelps immediately, while GSH content demonstrated in thesame way till12h. Both AsA content and GSH content increased significantly twice at36h,120h respectively. These results indicated that AsA was more sensitive andneeded less time to performance than GSH.We could conclude that the defense reaction was accomplished in two stages:36h-96h,120h-. It may be due to difference between local reaction and the overallreaction.3、SummaryDefense mechanism was motivated through promoting some enzymes activityafter thallus excision, in order to recorver normal state, and compensation waspromoted through growth mode change, increasing uptake rates of nutitions andpigment content, CN accumulation and allocation. |
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