Genetic diversity for chemical, agronomical, morphological and molecular characters in cassava (Manihot esculenta Crantz) accessions originated from different regions in Brazil

• Grant number: 10/20484-4
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2011
• End date: April 30, 2013
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Elizabeth Ann Veasey
• Grantee: Elizabeth Ann Veasey
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated researchers: Cássia Regina Limonta Carvalho ; José Carlos Feltran ; Paulo Roberto Nogueira Carvalho ; Teresa Losada Valle

Abstract

The project goal is to characterize and determine the genetic diversity among cassava accessions from different regions in Brazil, belonging to the germplasm bank of the Luiz de Queiroz College of Agriculture (ESALQ/USP) and the Agronomic Institute (IAC). The accessions comprising the germplasm bank of ESALQ and IAC will be evaluated through morphological and molecular (microsatellite) markers. Another 83 cassava accessions, originated from the Amazon, Central West, Southeast and South regions, will be assessed through agronomic, chemical and morphological traits, and molecular markers. Twelve morphological, four agronomical and six chemical traits, related to the roots, will be evaluated. For the molecular analysis, 14 microsatellite loci will be tested. For the assessment of the agronomic and chemical characters an experiment will be conducted in a randomized blocks design with three replications. Data will be analyzed using univariate (F test, mean test) and multivariate (cluster analysis and principal component analysis) statistical analysis.The individual genotypes will be grouped according to their swidden fields, communities and/or regions, to estimate allelic and genotypic frequencies, and genetic diversity parameters such as number of alleles per locus, percentage of polymorphic loci, mean observed and expected heterozygosity, and Nei's diversity indexes. These parameters will allow the characterization of the genetic diversity between and within swiddens, communities and/or geographic regions. Binary data (presence/absence of bands) will be used also for the construction of a dendrogram, to verify possible duplicates. (AU)