PEREMAJAAN BIBIT RUMPUT LAUT Gracilaria verrucosa HASIL KULTUR JARINGAN MELALUI SELEKSI MASSA

Abstract

Penelitian ini bertujuan untuk menguji performa bibit rumput laut Gracilaria verrucosa hasil kultur jaringan yang diremajakan dengan metode seleksi massa. Penelitian dilaksanakan di tambak percobaan Marana, Maros, Sulawesi Selatan; menggunakan dua petakan tambak berukuran sekitar 2.500 m2. Seleksi dilakukan berdasarkan perhitungan laju pertumbuhan harian (LPH), menggunakan sistem long line selama dua siklus dengan durasi 30 hari/siklus. Bibit rumput laut hasil seleksi kemudian dipelihara dengan sistem tebar dasar dan dibandingkan dengan kontrol internal dan kontrol eksternal dengan memasang sembilan unit hapa berukuran 1 m x 1 m x 1 m, dengan tiga ulangan untuk masing-masing perlakuan. Perhitungan LPH, kandungan agar, dan kekuatan gel dilakukan setiap 30 hari dan setiap 15 hari dilakukan monitoring terhadap kualitas air yakni salinitas, suhu, nitrat, dan fosfat. Hasil yang diperoleh memperlihatkan adanya peningkatan LPH yang signifikan (P<0,05) dari siklus-I (2,67 ± 0,38%/hari) menjadi (3,56 ± 0,25%/hari) pada siklus-II, dengan respons seleksi sebesar 21,48%-22,34% dan diferensial seleksi sebesar 9,70%-10,16%. Pertumbuhan rumput laut hasil seleksi lebih tinggi (3,23 ± 0,50%/hari) dibandingkan dengan kontrol internal (2,12 ± 0,02%/hari), dan kontrol eksternal (1,69 ± 0,09%/hari) (P<0,05). Kontrol internal memiliki kandungan agar yang lebih tinggi (20,07 ± 12,97%) dari rumput laut hasil seleksi (16,07 ± 1,58%) dan kontrol eksternal (8,29 ± 1,69%) (P<0,05); namun hasil seleksi memiliki kekuatan gel yang lebih tinggi (761,15 ± 208,90 g/cm2) dari kontrol internal (322,44 ± 244,29 g/cm2), dan kontrol eksternal (297,42 ± 44,16 g/cm²) (P<0,05). Peremajaan bibit rumput laut hasil kultur jaringan dengan metode seleksi massa mampu meningkatkan performa bibit rumput laut G. verrucosa.

This study was aimed to determine the performance of tissue-cultured seaweed seed Gracilaria verrucosa, which was propagated using mass selection method. The study was conducted in the experimental ponds in Marana, Maros,  South Sulawesi. The mass selection was conducted in two ponds of 2,500 m2. The selection was made by culturing the seaweed seed using the long line system for two cycles in 30 days/cycle duration during which the daily growth rates (DGR) of seaweed seeds were measured. The selected seaweed seeds were then cultivated in the ponds using broadcast system and the growth was compared with the internal and external controls consisted of nine units of 1 m x 1 m x 1 m hapa, with three replications for each treatment (selected seed, internal control, and external control). The measurements of DGR, agar yield, and gel strength were conducted every 30 days, while water quality monitoring i.e. salinity, temperature, nitrate, and phosphate were conducted every 15 days. The results showed that the DGR of seaweed seed increased significantly (P<0.05) from 2.67 ± 0.38%/day in cycle-I to 3.56 ± 0.25%/day in cycle-II, the selection response was 21.48%-22.34% and the differential selection was 9.70%-10.16%. The daily growth rate of selected seaweed seed was significantly higher (3.23 ± 0.50%/day) (P<0.05) compared to internal (2.12 ± 0.02%/day) and external controls (1.69 ± 0.09%/day). Internal control has higher agar yield (20.07 ± 12.97%) compared to the selected seed (16.07 ± 1.58%) and external control (8.29 ± 1.69%) (P<0,05). The selected seed has higher gel strength (761.15 ± 208.90 g/cm2) compared to internal control (322.44 ± 244.29 g/cm2), and external control (297.42 ± 44.16 g/cm2) (P<0,05). Propagated tissue-cultured seaweed seed using the  mass selection method could improve the overall performance of seaweed seed.