| 摘要: | 矽藻的形態會隨著培養條件而有多樣化的變異，釵h同種異名與新種名的修正，使得矽藻鑑定至種較為困難。本研究主要目的，在於分離與純化臺灣西南沿岸之矽藻，以探討其親緣關係，並探討矽藻在水產養殖上的應用。結果顯示：以Marine enrinchment medium f/2 修正培養基在光照90μmol photon m−2 s−1，溫度30℃，濕度70％的培養條件，可以分離純化臺灣西南沿岸之矽藻，經光學顯微鏡(LM)及掃描式電子顯微鏡(SEM)觀察與鑑定結果，發現共分離出3屬10種矽藻，包括羽紋矽藻目(Pennatae)的雙眉藻屬(Amphora)、舟形藻屬(Navicula)及圓心矽藻目(Centricae)的小環藻屬(Cyclotella)，分別編號為STSP1(Amphora sp1)、STSP2 (Amphora sp2)、STSP3(Amphora sp3)、STSP8 (Cyclotella sp1)、STSP9 (Cyclotella sp2)、ERSP5(Navicula sp4)、ERSP6 (Amphora sp4)、GCSP1 (Amphora sp5)、CKSP1(Amphora sp6)及JJSP3 (Amphora sp7)等10種。
經分離純化之十種矽藻，進一步分析其18S rDNA 之片段基因序列，以探討彼此間之遺傳關係。結果以Neighbor-Joining 方法所執行之歸群分析，
顯示可將所分離純化之十種矽藻分為四個群。因此經由分子生物鑑定發現本研究所分離的矽藻可能只有五種，包括Amphora sp1 (STSP1)、 Amphora sp2 (STSP2, GCSP1, CKSP1, ERSP6, JJSP3)、 Amphora sp3 (STSP3)、Cyclotella sp1 (STSP8,STSP9) 及Navicula sp4 (ERSP5)等五種。
本研究進一步應用三種生長速率較快之矽藻:STSP1 (Amphora sp1)、JJSP3 (Amphora sp2) 及 ERSP5 (Navicula sp4) 於水產養殖，實驗以三種矽藻製備含藻餌料，分別培育金目鱸魚的魚苗，經51 天之培育結果顯示:添加矽藻JJSP3 (Amphora sp7) 的飼料，會使金目鱸魚有較高的增重率、增長率、飼料效率。而添加矽藻STSP1 (Amphora sp1) 的飼料會使金目鱸魚有較高的存活率。
For the morphology of diatoms could vary with the culture conditions, the synonym and new species revision made the identification of diatom species more difficult. This study focused on the isolation, identification and phylogenetic relationship of diatoms taken from southwestern Taiwan and their applicability in aquaculture for larval fish culture. The results showed that the local diatoms could be isolated from the nature by the Marine enrichment medium f/2 medium under conditions of 30℃, humidity 70％ and light intensity 90μmol．photons．m-2．s-1.
Under the light microscope (LM) and scanning electric microscope (SEM), a total of ten species including strain STSP1(Amphora sp1), STSP2 (Amphora sp2), STSP3 (Amphora sp3), STSP8 (Cyclotella sp1), STSP9 (Cyclotella sp2), ERSP5(Navicula sp4), ERSP6 (Amphora sp4), GCSP1 (Amphora sp5), CKSP1 (Amphora sp6) and JJSP3(Amphora sp7) were identified.
Furthermore, this study tried to differentiate the genetic difference among ten isolated diatoms with 18S rDNA sequencing techniques. Cluster analysis by the method of Neighbor-Joining (NJ) demostrated that ten purified diatoms could be grouped into four clusters and there were only five species of Amphora sp1 (STSP1), Amphora sp2 (STSP2, GCSP1, CKSP1, ERSP6, JJSP3), Amphora sp3 (STSP3), Cyclotella sp1 (STSP8,STSP9), Navicula sp4 (ERSP5) were isolated according to compare their 18S rDNA gene, partial sequence.
In addition, three species of STSP1 (Amphora sp1), JJSP3 (Amphora sp2) and ERSP5 (Navicula sp4) were studied the applicability in aquaculture for larval fish culture. Our results showed that JJSP3 (Amphora sp2) into feeds will induce higher larval length, larval weight and feed efficiency. However, adding STSP1 (Amphora sp1) into feeds will induce higher survival. |
