tailieunhanh - Báo cáo sinh học: "Genotype by environment interaction for adult body weights of shrimp Penaeus vannamei when grown at low and high densities"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học quốc tế đề tài: Genotype by environment interaction for adult body weights of shrimp Penaeus vannamei when grown at low and high densities | Genet. Sel. Evol. 40 2008 541-551 INRA EDP Sciences 2008 DOI gse 2008020 Available online at Original article Genotype by environment interaction for adult body weights of shrimp Penaeus vannamei when grown at low and high densities Ana M. Ibarra1 Thomas R. Famula2 1Aquaculture Genetics and Breeding Laboratory Centro de Investigaciones Biologicas del Noroeste . Mar Bermejo 195 La Paz . 23090 Mexico 2Department of Animal Science University of California Davis 1 Shields Avenue Davis CA 95616 USA Received 14 June 2007 accepted 1st April 2008 Abstract - Shrimp is one of few marine species cultured worldwide for which several selective breeding programs are being conducted. One environmental factor that can affect the response to selection in breeding programs is the density at which the shrimp are cultured low-medium-high . Phenotypic plasticity in the growth response to different densities might be accompanied by a significant genotype by environment interaction evidenced by a change in heritabilities between environments and by a genetic correlation less than one for a unique trait between environments. Our goal was to understand whether different growth densities affect estimates of those genetic parameters for adult body weight BW in the Pacific white shrimp Penaeus vannamei . BW heritabilities were significantly different between environments with the largest at high density. These differences resulted from both an increased additive genetic variance and a decreased environmental variance when grown at high density. The genetic correlation between BWs at the two environmental conditions was significantly less than one. Whereas these results might be suggestive for carrying out shrimp selective breeding for BW under high density conditions further understanding of genetic correlations between growth and reproductive traits within a given environment is necessary as there are indications of reduced reproductive fitness for shrimp