| 摘要: | 為探討台灣西南部的矽藻之親緣演化關係，本研究以海水與半鹽水浮游性矽藻為主要的研究對象，除分離純化與鑑定台灣西南部海水與半鹽水浮游性矽藻外，並進一步探討矽藻在水產養殖上的應用。研究分為三個部份進行：1.自14個採樣點收集浮游性樣品，將樣品分離純化，以利用光學顯微鏡與掃描式電子顯微鏡鑑定是否為純種，當純化出純種後，進行矽藻物種鑑定，並將藻種保存。2.抽取純化後藻種DNA，利用PCR複製部份18S rDNA序列，並定序，利用所得的部分18S rDNA序列與NCBI資料庫現有的藻種比對。3.選出易大量培養的純種矽藻來餵食魚類，評估以矽藻做為魚苗餌料的可行性。結果共由其中4個採樣點分離出十種矽藻，包括由(1)四草野生動物保護區分離出的STSP4 (Amphora sp8)、STSP5 (Amphora sp9)、STSP6 (Amphora sp10 )，(2)由四草大眾廟附近之海堡橋分離出的STSP8 (Cyclotella sp1)、STSP9 (Cyclotella sp2)，(3)由二仁溪下游分離出的ERSP2 (Amphora sp)、ERSP3 (Cyclotella sp3)、ERSP4 (Navicula sp5)，(4)由黃金海岸所分離出GCSP3 (Navicula sp6)、GCSP4 (Navicula sp7)等10種。
十種純種矽藻以PCR技術放大其18S rDNA的片段的基因序列，再利用歸群分析法繪製出十種純種矽藻之親緣關係圖，顯示可將分離純化出來的矽藻共分為五群。故經由矽藻細胞壁形態鑑定與分子鑑定輔助，發現所分離的矽藻可能只有七種，包括Amphora sp8 (STSP4)、Amphora sp9 (STSP5)、Amphora sp10 (STSP6)、Amphora sp11(ERSP2)、Cyclotella sp1 (STSP8、STSP9、ERSP3)、Navicula sp5 (ERSP4)、及Navicula sp6 (GCSP3、GCSP4)。
本研究進一步選擇以STSP4、ERSP2、GCSP3等三種矽藻製備含藻餌料以培育金目鱸魚的魚苗，經50天之培育結果顯示:餵食金目鱸魚幼苗含有STSP4 (Amphora sp8)的混合飼料組，魚苗活存率、增重率、增長率及飼料轉換係數，在所有實驗組當中為最佳的生物餌料。
Marine and brackish water diatoms were collected from southwestern Taiwan, to processed diatom isolated, identification and Phylogenetic relationship.
This study can divided into three parts: 1.Collection and isolation planktonic samples from fourteen sampling station, identified under the light microscope (LM) and scanning electric microscope (SEM). After purify the pure species, to proceed identification of diatom and storage. 2. DNA was extraction from the pure diatoms, and using PCR technique to amplify the 18S rDNA gene. The PCR products were sequenced. These partial 18S rDNA sequence was submitted in a BLAST search. 3. Choose easy to mass culture species were used to as larvae feeds. Discuss the feasibility of larvae feed use of diatom.
Under the light microscope (LM) and scanning electric microscope (SEM), a total of ten species including strain STSP4(Amphora sp), STSP5 (Amphora sp), STSP6 (Amphora sp), STSP8 (Cyclotella sp), STSP9 (Cyclotella sp), ERSP2 (Amphora sp), ERSP3 (Cyclotella sp), ERSP4 (Navicula sp), GCSP3 (Navicula sp), GCSP4 (Navicula sp), 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 five clusters and there were only seven species of Amphora sp8 (STSP4), Amphora sp9 (STSP5), Amphora sp10 (STSP6), Amphora sp11 (ERSP2), Cyclotella sp1(STSP8,STSP9) , Cyclotella sp2(ERSP3), Navicula sp5 (ERSP4), Navicula sp6 (GCSP3、GCSP4) were isolated according to compare their 18S rDNA gene partial sequence.
In addition, three species of STSP4(Amphora sp8), ERSP2(Amphora sp11) and GCSP3(Navicula sp6) were studied the applicability in aquaculture for larval fish culture. Our results showed that adding STSP4 (Amphora sp8) into feeds will induce the highest larval length, larval weight, feed efficiency and survival. |
