Molecular characterization of papaya genotypes using AFLP markers

Abstract

-Due to the low genetic variability reported in the commercial plantations of papaya (Carica papaya L.), the objective of this study was analyze the genetic diversity of 32 genotypes including cultivars, landraces, inbred lines, and improved germplasm using the AFLP technique (Amplified Fragment Length Polymorphism). The genetic distance matrix was obtained using the Nei and Li genetic distance and clustering was performed using the unweighted pair-method with arithmetic mean (UPGMA). Using 11 combinations of EcoRI/MseI primers, 383 polymorphic bands were obtained. On average, 34.8 polymorphic bands were obtained per primer combination. Five clusters were formed. The traditional cultivar 'Sunrise' and the inbred line CMF-L30-08 were the closest genotypes, and the improved germplasm (CMF041) and landrace (CMF233) the most distant. The main papaya cultivars commercially grown in Brazil, as well as four inbred lines and three improved germplasm, were clustered together, however, were not grouped in the same branch. The genetic distance between the Sunrise and Golden cultivars was 0.329, and even arising from mutation and selection within the Sunrise variety, the Golden stores considerable genetic variability. Additional variability was observed in the inbred lines derived from papaya breeding program at Embrapa Cassava and Fruits. Index terms: papaya breeding, genetic resources, genetic diversity, Carica papaya L.. CARACTERIZAÇÃO MOLECULAR DE GENÓTIPOS DE MAMOEIRO COM USO DE MARCADORES DO TIPO AFLPRESUMO -Em virtude da baixa variabilidade genética relatada nos plantios comerciais de mamoeiro (Carica papaya L.), o objetivo deste trabalho foi analisar a divergência genética de 32 genótipos incluindo cultivares, variedades locais, linhagens e germoplasma melhorado, utilizando a técnica de AFLP (Amplified Fragment Length Polymorphism). A matriz de distâncias genéticas foi obtida com a distância de Nei e Li, e o agrupamento foi realizado utilizando o método UPGMA (unweighted pair-method with arithmetic mean). Utilizaram-se 11 combinações de iniciadores com corte das enzimas EcoRI / MseI. Foram geradas 383 bandas polimórficas, com média de 34,8 por combinação de iniciadores. O agrupamento dos dados permitiu a formação de cinco grupos, sendo a cultivar Sunrise e a linhagem CMF-L30-08 os genótipos mais relacionados, e CMF041 (germoplasma melhorado) e CMF233 (variedade local), os mais dissimilares. As cultivares de mamoeiro mais cultivadas no Brasil, bem como quatro linhagens e três acessos de germoplasma melhorado foram agrupadas, porém não no mesmo ramo. Mesmo sendo oriunda de mutação e seleção dentro de Sunrise, a cultivar Golden ainda possui considerável variabilidade genética, uma vez que a distância genética entre estas cultivares foi de 0,329. Variabilidade adicional foi observada nas linhagens do programa de melhoramento. Termos para indexação: melhoramento, recursos genéticos, diversidade genética, Carica papaya L..Rev. Bras.

Genetic diversity among papaya accessions

“…The varieties of the Solo group are planted in many regions of the world, producing fruit with desirable characteristics for export, with red flesh, small size and weight between 300 and 650 g. Fruits of the Formosa group have red flesh and average size between 1000 and 1300 g. According to Oliveira et al (2011), the Formosa group consists of commercial hybrids that have gained space in domestic and foreign markets, with strong sales growth in Europe, Canada and the United States.…”

“…A number of genetic divergence studies have also been carried out with different accessions of papaya (Carica papaya L.) (Ramos et al, 2011;Quintal et al, 2012;Oliveira et al, 2011;Lucena and Dantas, 2015). Therefore, the objective of this study was to evaluate, by means of variables, the genetic variability among 59 accessions of papaya that have not been previously evaluated in studies of genetic diversity.…”

Genetic diversity in two species of Caricaceae and their genetic relationship toCarica papayaL.

“…Tal fato pode indicar que os alelos presentes nas linhagens parentais do híbrido ainda não se encontram totalmente fixados. Oliveira et al (2011), estudando a diversidade genética via AFLP em genótipos de Carica papaya, observaram que a cultivar Sunrise foi mais próxima genotipicamente de uma linhagem endogâmica estudada (CMF-L30-08), quando comparado com genótipos landraces (CMF 233) na mesma espécie.…”

“…Silva et al (2007) empregaram com sucesso os marcadores RAPD para monitorar o avanço de gerações de autofecundação no progenitor Formosa do híbrido Uenf/Caliman 01. Ramos et al (2012) (KIM et al, 2002;OLIVEIRA et al, 2011), microssatélites (SSR -Simple Sequence Repeat) (EUSTICE et al, 2008;OCAMPO PÉREZ et al, 2006), RFLP (Restriction Fragment Lenght Polymorphism) (ARADHYA et al, 1999) e ISSR (COSTA et al, 2011). adicionou-se tampão de extração.…”

Informativeness of minisatellite and microsatellite markers for genetic analysis in papaya

“…For instance, Stiles et al (1993) used 11 random amplified polymorphism DNA (RAPD) molecular markers to evaluate the genetic relationships among ten papaya varieties. Other similar studies were developed by Kim et al (2002) and Oliveira et al (2011) to estimate diversity and to assess the genetic relationships among papaya accessions based on amplified fragment length polymorphism (AFLP) markers. However, RAPD and AFLP markers are considered dominant markers and present disadvantages such as a low content of genetic information per locus, an inability for genotypic discrimination, low reproducibility (especially RAPD), a large number of steps and a requirement for high-quality DNA (AFLP).…”