PEWARISAN MARKA Cyca-DAB1*05 DAN KERAGAMAN GENETIK IKAN MAS (Cyprinus carpio) STRAIN RAJADANU TAHAN INFEKSI KOI HERPESVIRUS DAN TUMBUH CEPAT

Abstract

Balai Penelitian Pemuliaan Ikan (BPPI) telah membentuk ikan mas Rajadanu tahan infeksi koi herpesvirus (KHV) dan tumbuh cepat melalui program seleksi. Ikan mas Rajadanu dihasilkan dari kegiatan seleksi bersamaan pada karakter ketahanan terhadap KHV dan pertumbuhan. Seleksi karakter ketahanan terhadap KHV dilakukan dengan menggunakan marka Cyca-DAB1*05 dan seleksi karakter pertumbuhan cepat dilakukan dengan metode seleksi individu. Penelitian ini bertujuan untuk mengevaluasi pewarisan marka Cyca-DAB1*05 dan keragaman genotipe ikan mas varietas Rajadanu tahan infeksi KHV dan tumbuh cepat generasi ketiga (F3). Sebanyak 44 individu ikan mas Rajadanu F3 digunakan pada penelitian ini. Evaluasi marka Cyca-DAB1*05 dilakukan dengan metode PCR menggunakan primer spesifik marka Cyca-DAB1*05. Analisis keragaman genotipe dilakukan menggunakan tiga lokus mikrosatelit (MFW6, MFW7, dan MFW9). Data alel mikrosatelit dianalisis menggunakan program Fstat dan Arlequin. Hasil penelitian menunjukkan bahwa semua individu pada populasi ikan mas Rajadanu F3 membawa marka Cyca-DAB1*05. Ikan mas Rajadanu F3 memiliki keragaman genotipe yang relatif rendah. Nilai rata-rata heterozigositas teramati (0,31) lebih kecil daripada rata-rata heterozigositas harapan (0,46). Nilai positif pada indeks fiksasi (0,32) menunjukkan status inbreeding pada populasi tersebut. Hasil penelitian ini dapat menjadi acuan, baik dalam kegiatan manajemen induk maupun dalam program seleksi selanjutnya dengan tujuan untuk mempertahankan keragaman genetik dan meminimasi tekanan inbreeding ikan mas Rajadanu tahan infeksi KHV dan tumbuh cepat.

Research Institute for Fish Breeding (RIFB) has created Rajadanu common carp resistant to koi herpesvirus (KHV) infection and fast growth through selection program. Rajadanu common carp has been produced by independent culling selection on resistant to KHV and fast growth characters. Selection on resistant to KHV and fast growth character was conducted using Cyca-DAB1*05 marker and mass-selection method respectively. The aim of this study was to evaluate the inheritance of Cyca-DAB1*05 as a marker and the genotype variation of Rajadanu common carp resistant to KHV infection and fast growth. A total of 44 fish were used for this study. Evaluation of Cyca-DAB1*05 marker was conducted by PCR method using specific primer to Cyca-DAB1*05 marker. Analysis of genotype variation was conducted using three microsatellite loci (MFW6, MFW7, and MFW9). Microsatellite allele data was analyzed using Fstat and Arlequin software. The result showed that all of F3 Rajadanu common carp were positive carrying Cyca-DAB1*05 marker. Genetic variation of this population was relatively low. The average observed heterozygosity (Ho=0.31) was lower than the average expected heterozygosity (He=0.46). Positive value of fixation index (0.32) showed inbreeding status in this population. The result of this study can be use as reference for broodstock management and next selection program to maintain the genetic diversity and to minimize inbreeding depression level of Rajadanu common carp resistant to KHV infection and fast growth.