INTERAKSI GENOTIPE DENGAN LINGKUNGAN, ADAPTABILITAS, DAN STABILITAS PENAMPILAN FENOTIPIK EMPAT VARIETAS UNGGUL IKAN NILA (Oreochromis niloticus)

Abstract

Penampilan fenotipik suatu organisme ditentukan oleh faktor genetik dan dipengaruhi oleh faktor lingkungan tempat organisme tersebut hidup. Dalam beberapa kasus, interaksi antara faktor genetik dengan lingkungan juga berpengaruh terhadap penampilan fenotipik yang dihasilkan. Penelitian ini bertujuan untuk mempelajari interaksi antara faktor genetik dengan lingkungan, daya adaptabilitas dan stabilitas penampilan fenotipik khususnya bobot individu pada empat varietas unggul ikan nila yang dipelihara di tiga lokasi berbeda. Ikan nila varietas GMT, merah NIFI, NIRWANA dan BEST dipelihara di tambak payau di Indramayu, kolam air tenang di Sukamandi dan karamba jaring apung di Waduk Cirata, Kabupaten Cianjur, selama empat bulan pemeliharaan. Benih ikan nila diberi pakan pelet komersial dengan kandungan protein kasar 28%-30%, sebanyak 10%; 7,5%; 5%; dan 2,5% dari biomassa ikan masing-masing pada bulan pertama, kedua, ketiga, dan keempat. Pakan diberikan dengan frekuensi dua kali setiap hari. Hasil penelitian menunjukkan bahwa bobot ikan nila secara nyata dipengaruhi oleh faktor genetik, lingkungan, serta interaksi antara kedua faktor tersebut. Selain ikan nila GMT, tiga varietas ikan nila yang diuji mempunyai adaptabilitas lingkungan relatif sempit, serta stabilitas penampilan fenotipik karakter bobot individu relatif rendah. Hal ini mengindikasikan bahwa pengembangan budidaya ikan nila GMT dapat dilakukan di semua lokasi, sedangkan ikan nila merah NIFI, NIRWANA, dan BEST akan optimal jika dilakukan di lokasi tertentu saja.Phenotypic performance was determined by genetic and environment factors and their interaction. This study was conducted to examinethe present of interaction both of genetic and environment factors, adaptability, and stability of phenotypic performance of four varieties of tilapia which maintained in three different location. GMT, red NIFI, NIRWANA, and BEST tilapia strains were reared for four months in net cages in Cirata reservoir in Cianjur, in earthen ponds in Sukamandi and in brackish water ponds in Indramayu. All fish were fed with commercial pelleted feed contained of crude protein 28%-30%, about 10%, 7.5%, 5%, and 2.5% each day in 1st, 2nd, 3rd, and 4th month, respectively. The results showed that tilapia’s phenotipic performance especially the average body weight was significantly affected by genetic factor, environment factor, and interaction both of them factors. Except the GMT, all tilapia strains used in this study have narrow phenotypic adaptability and stability, especially in average body weight. This results indicated that GMT tilapia strain can be farmed in various areas, but red NIFI, NIRWANA, and BEST tilapia strains are most likely in a specific location.

Evaluation of Growth Performance and Improving Genetic Gain of Blue Tilapia (<I>Oreochromis aureus</I>) Fourth-generation (F-4) at Brackish Water Pond

“…dos Santos et al (2012) reported that selected tilapia showed faster growth compared to natural populations due to differences in metabolic rates, muscle and adipose tissue growth, and different organ sizes, causing changes in carcass and meat quality. Added by Ariyanto and Listiyowati (2015), the adaptability of fish affects the phenotypic appearance, where strains with broad adaptability will have a relatively good phenotypic appearance in various environmental conditions, while varieties with relatively narrow adaptability will have a phenotypic appearance that is strongly influenced environmental conditions in which the genotype was developed. Villegas (1990) and Armas-Rosales ( 2006) stated that fish size can affect the salinity tolerance of tilapia, which indicates that larger fish sizes can adapt better than smaller fish.…”

Pengaruh Genotipe, Lingkungan, Dan Interaksi Keduanya Terhadap Stabilitas Penampilan Fenotipik Ikan Mas

“…Genotipe yang mampu bertahan hidup pada kondisi lingkungan yang kurang menguntungkan umumnya mempunyai penampilan karakter biometrik yang lebih baik dibanding genotipe-genotipe yang kurang mampu bertahan hidup. Beberapa penelitian terkait pengaruh genotipe, lingkungan dan interaksi keduanya sudah dilaporkan, antara lain pada ikan nila (Eknath et al, 1993;Charo-Karisa et al, 2006;Khaw et al, 2012;Ariyanto & Listiyowati, 2015), ikan salmon (Gjedrem, 2005), ikan cod (Bangera et al, 2015), ikan lele (Dunham et al, 1990), ikan mas (Wang & Li, 2007), dan ikan kakap (Dupont-Nivet et al, 2008).…”

Evaluation of larvae production and growth of juvenile red tilapia NIFI F1 during the nursery phase

“…Koefisien keragaman karakter bobot be- Ariyanto & Listiyowati (2015) bahwa pemanfaatan varietas unggul selain mempunyai tingkat produktivitas yang relatif stabil pada berbagai lokasi budi daya, pemanfaatan varietas unggul tersebut juga mengurangi risiko kegagalan panen jika terjadi perubahan kondisi lingkungan yang sulit diramalkan.…”