GENETIC DIVERSITY OF UNIQUE AND DOMINANT MACROALGAE ON INDONESIAN COASTAL AREA OF SAYANG HEULANG, GARUT, WEST JAVA

• Main Author: SOFI YANTY (NIM: 20514025), JANNAH
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20221
• Institution: Institut Teknologi Bandung

Macroalgae or seaweeds are multi-cellular algae plants that live in waters. They could be easily found in almost all of Indonesian coastal areas. Macroalgae belonging to the division Thallophyta, and they are grouped into classes of green algae, brown algae and red algae. Reports on diversity of Indonesian marine macroalgae are still limited to diversity based on differences in phenotype only, not genetics. Sayang Heulang beach is one of the Indonesian beaches located in the district of Garut, West Java, which has a lot of natural resources including macroalgae that grows naturally and is widespread in coastal areas. The aim of this study is to map the genetic diversity of Indonesian marine macroalgae. The study began with the collection of macroalgae samples in Sayang Heulang beach at coordinates of 107o41'16" - 107o41'24" E and 7o40'0" - 7o40'6" S. Then, DNA was extracted from macroalgae by CTAB method and Wizard Genomic DNA Purification kit (Promega). DNA in extracts was visualized by agarose gel electrophoresis. PCR amplification was carried out to isolate the V4 region of 18S rRNA gene (18S rRNA V4) and then sequencing was done to the PCR products. DNA sequence of 18S rRNA V4 was confirmed with BLAST from NCBI database. Phylogenetic analysis was performed using software of MEGA 6. Alignment of DNA sequences was performed using ClustalW program, and the inference of phylogenetic trees was confirmed by neighbor joining method. In this research 3 types of macroalgae, i.e. green algae, red algae and brown algae have been collected. Nine samples of macroalgae have been successfully mapped genetically based on the nucleotide sequence of 18S rRNA gene at V4 region (18S rRNA V4). GA samples, which are morphologically similar to Gelidiella acerosa, have 99% 18S rRNA V4 sequence similarity with Pterocladiella caerulescens, Gelidium australe, and Pterocladiella capillacea. GV which is morphologically similar to Gracilaria verrucosa, has 94% sequence similarity of 18S rRNA V4 with Gracilaria sp. and Gracilaria corticata. GSp which is morphologically close to Gracilaria sp., has 99% similarity of 18S rRNA V4 sequence with Gracilaria aff. Mammillaris strain Sao Paulo, Gracilaria chouae, Gracilaria salicornia, and Gracilaria curtissiae. HSp which morphologically has similarity to Hypnea sp., genetically is identical (100% 18S rRNA V4 similarity) with Hypnea sp. asiatica and Hypnea charoides. SB which was morphologically close to Sargassum binderi, has 99% 18S rRNA V4 similarity to Sargassum vachellianum and Sargassum thunbergii. SP which is morphologically similar to Sargassum polycistum, havs 99% 18S rRNA V4 similarity with Sargassum vachellianum and Sargassum thunbergii. TC which was morphologicallycloseto Turbinaria conoides, has 99% 18S rRNA V4 similarity to Cystoseira schiffneri and Sargassum vachellianum. UF which morphologically has the closest similarity to Ulva fasciata, has 100% similarity of 18S rRNA V4 Ulva sp. 3K, Ulva fasciata and Ulva rigida. GM1 which were morphologically close to Derbesia sp., has 99% 18S rRNA V4 similarity with Spyridia filamentosa. Multiply alignments of 18S rRNA V4 sequences of red macroalgae samples indicate that there are unique sequences or specific DNA code in each of macroalgae GV, GA and GSP, that could be use to distinguish them from other red macroalgae. But unique sequence was not found in HSP. In case of brown macroalgae, specific DNA codes were found in samples of SP and TC, while in SB was not found. And for green macroalgae samples, specific DNA codes were found in GM1, not in UF. Eight of nine samples analyzed showed results that correspond between morphological approach to the genetic approach. One sample of GM1 which was morphologically similar to Derbesia sp. (green algae), genetically has the highest similarity to Spyridia filamentosa (a red algae). Study on GenBank data showed that 18S rRNA gene sequence for the species Derbesia sp. was not available in Genbank. Only sequences of rbcL and tufA gene were available in GenBank for Derbesia sp. This might cause the results of genetic analysis of Derbesia sp. was not corresponding with the results of the morphology analysis. This research could be continued by analysing further all samples using other variables such V2 and V9 region of 18S rRNA gene to get a more comprehensive sequences.