Kelangsungan hidup ikan lele (Clarias gariepinus) generasi kedua pembawa marka SNP2 gen Lys-C terhadap cekaman nitrit

Abstract

Budidaya intensif dapat menimbulkan senyawa beracun seperti nitrit. Ikan lele yang memiliki marka single nucleotide polymorphism 2 (SNP2) gen Lys-C merupakan hasil pemuliaan dengan ketahanan terhadap Aeromonas hydrophila. Namun, ikan ini belum dianalisis kelangsungan hidupnya terhadap cekaman nitrit. Penelitian ini bertujuan menganalisis kelangsungan hidup ikan lele generasi kedua yang membawa marka SNP2 gen Lys-C terhadap cekaman nitrit. Ikan lele bergenotipe TT disilangkan dan dipelihara sampai mencapai ukuran 8-9 cm. Analisis pewarisan genotipe dilakukan dengan metode polymerase chain reaction. Uji cekaman dilakukan dengan nitrit konsentrasi 10 ppm sebanyak 20 ekor per perlakuan dengan 3 kali ulangan dari 3 persilangan TT⨯TT dan satu persilangan induk sangkuriang sebagai pembanding. Parameter yang diamati yaitu tingkat kelangsungan hidup, kualitas air, jumlah eritrosit, dan kadar glukosa. Hasil menunjukkan bahwa persilangan TT⨯TT memiliki keturunan 100% bergenotipe TT, sedangkan lele sangkuriang memiliki 3 genotipe berbeda. Tingkat kelangsungan hidup pasca cekaman nitrit berkisar 55,00-68,33%, lebih rendah dibandingkan sangkuriang (73,33%).

Intensive cultivation can produce toxic compounds such as nitrite. Catfish with a single nucleotide polymorphism 2 (SNP2) marker in the Lys-C gene are the result of breeding for resistance against Aeromonas hydrophila. However, the survival of these fish under nitrite stress has not been analyzed. This study aims to analyze the survival of second-generation catfish carrying the SNP2 marker in the Lys-C gene under nitrite stress. Catfish with the TT genotype were crossed and reared until they reached a size of 8-9 cm. Genotype inheritance analysis was performed using the polymerase chain reaction method. Nitrite stress tests were conducted with a concentration of 10 ppm on 20 individuals per treatment, with 3 replications of the TT⨯TT cross and one replication of the Sangkuriang parental cross as a comparison. The parameters observed were survival rate, water quality, erythrocyte count, and glucose level. The results showed that the TT⨯TT cross had offspring that were 100% TT genotype, while Sangkuriang catfish had three different genotypes. The post-nitrite stress survival rate ranged from 55.00 to 68.33%, which was lower than that of Sangkuriang catfish (73.33%).