Tilapia strains adopted in Vietnam determined by discriminant analysis of principal components (DAPC) of single-nucleotide polymorphisms (SNP)

Abstract

Quantifying the adoption of genetically-improved outcrossing species, such as GIFT tilapia, is inherently more difficult than for hybrid/inbred crop lines or clonal horticultural varieties – primarily due to the degree of genetic variation in disseminated populations and temporal changes in the genetic quality and characteristics of strains. In this context, Hamilton (2020) developed a tool using a low-density panel of single-nucleotide polymorphisms (SNP), genotyping-by-sequencing and discriminant analysis of principal components (DAPC) to identify different and interrelated strains of Nile tilapia in Bangladesh and the Philippines. This study verified the importance of GIFT and GIFT-derived strains to tilapia aquaculture in these countries, while identifying the limitations of this method, given the aforementioned difficulties. Using the approach detailed in Hamilton (2020), the current study had three objectives: • identify and develop new SNP markers; • characterize core breeding populations and key tilapia strains released in Vietnam; and • assess the current adoption of GIFT-derived and non-GIFT-derived strains at the hatchery and farm-levels in Vietnam.