Caracterização e diversidade genética de isolados de Phytophthora spp. do cacaueiro com base em marcadores RAPD

Abstract

Characterization and genetic diversity of Phytophthora spp. isolates from cacao based on RAPD markersThis paper deals with the study of the genetic diversity of the three most important species of Phytophthora causing cacao (Theobroma cacao) black pod disease in Brazil. RAPD molecular markers were used to study the genetic diversity among eight isolates of P. capsici, five of P. palmivora and nine of P. citrophthora. Genomic Objetivou-se neste trabalho estudar a diversidade genética entre isolados das três principais espécies do gênero Phytophthora causadoras da podridão-parda do cacaueiro (Theobroma cacao) no Brasil, utilizando marcadores moleculares RAPD. Foram utilizados 22 isolados de Phytophthora spp., sendo oito de P. capsici, cinco de P. palmivora e nove de P. citrophthora. DNA genômico de cada isolado foi extraído e amplificado utilizando-se sete "primers" decâmeros, os quais geraram 191 marcadores RAPD. Distâncias genéticas e análises de agrupamento realizadas com base nestes marcadores permitiram uma diferenciação clara dos isolados de cada espécie e mostraram diferentes níveis de diversidade intra-específica. Ficou evidente o potencial dos marcadores RAPD como uma ferramenta auxiliar na classificação dos isolados e, também, em estudos de diversidade genética intra-específica.Palavras-chave adicionais: Phytophthora capsici, P. palmivora, P. citrophthora, Theobroma cacao, marcadores moleculares, podridão-parda. ABSTRACTDNA of each isolate was extracted and amplified using seven decamer primers which generated 191 RAPD markers. The genetic distances and cluster analysis based on these molecular markers made it possible to differentiate the isolates of each species and showed different levels of intraspecifc variation. These results confirm the potential of RAPD markers as an auxiliary tool for the classification of Phytophthora spp. isolates and also to study intraspecific genetic variability.

Phenotypic and genotypic characterization and compatibility among genotypes to select elite clones of cupuassu

“…There is also a need to improve the productivity and quality of pulp and seeds to meet the future demands of the agribusiness sector. For cocoa, similar results as ours have been reported by Faleiro et al (2001), who studied the clonal varieties recommended to the cocoa producers.…”

Genetic molecular diversity, production and resistance to witches' broom in cacao clones

“…DNA samples of each plant were extracted from healthy leaves in intermediate stage of maturation using the CTAB method (Doyle and Doyle 1990) with modifications (Corrêa et al 1999, Faleiro et al 2001, Queiróz et al 2003. The integrity and purity analysis of the DNA samples was carried out by electrophoresis in agarose gel at 1%, dyed with ethidium bromide 1 ng/mL, and compared with known concentration patterns (lambda phage DNA, λ).…”

Microsatellite diversity and heterozygosity of parents of a cocoa breeding population

“…NCL is the sum of allelic coincidences of each analyzed locus, where each coincidence is assigned value 1 for the matches (2 2); 0.5 for the matches (2 1), (1 2) and (1 1) and 0 for the matches (0 1), (1 0) and (2 0) Faleiro et al (2001) The matrix of genetic distances was used for cluster analyses via dendrogram, by the UPGMA method (Unweighted Pair Group Method with Arithmetic Mean) as grouping criterion. The genetic distance matrix was shown in a scatter plot based on multidimensional scaling, using the principal coordinate analysis method, as discussed by Dias (1998).…”

“…In general, Forasteros from the Upper Amazon have the greatest genetic diversity (Pires 2003, Marita et al 2001. The genetic base of the trees in Bahia cacao plantations was narrow until the CEPLAC began to recommend hybrids , even at the beginning of the recommendation of clones Faleiro et al 2001). Recently, Bertolde (2007) demonstrated the high genetic diversity in 38 recommended clones using microsatellite markers.…”