Pedro de Queiroz Costa Neto

Variabilidade genética de Colletotrichum guaranicola usando marcadores AFLP

The genetic variability of twenty Colletotrichum guaranicola (Albuq.) isolates from different fields of guarana in Amazonas, was studied using molecular AFLP markers. The isolates were separated into two groups. The genetic variability coefficient was 0.0216 and the genetic similarity was 94.5%, confirming that the isolates belongs to the same species, however, an intra-specific variability was observed.

Genetic diversity in natural populations of Buriti (Mauritia flexuosa L. f.)

This study aimed to characterize the genetic diversity of buriti populations by AFLP (Amplified Fragment Length Polymorphism) markers. The analysis was performed in four populations used by traditional communities in the state of Amazonia (Bom Jesus do Anama, Lauro Sodre, Santa Luzia do Buicuzinho, and Esperanca II). From each population 30 plants were randomly selected. To obtain the markers four primer combinations were used. The percentage of polymorphic loci was estimated, the molecular variance among and within populations analyzed and a dendrogram constructed. The primers detected 339 polymorphic loci ranging from 81.1 % to 91.1 % among populations. Analysis of molecular variance attributed 77.18 % to variation within and 22.8 % to variation between populations. The dendrogram indicated the formation of two groups, showing that the populations of Bom Jesus do Anama and Lauro Sodre are genetically most similar and thet the genetic and geographical distances are not correlated.

Molecular Study of the Genetic Variability of Pumpkins Landraces from Brazilian Amazon

The Cucurbita maxima Duchesne is a vegetable crop plant cultivated and maintained by traditional Amazon communities, Brazil. The situation is worsened by the possibility of disappearance of local populations and genetic variability of this specie, taking into account the today changes promoted in family farming. The aim of this study was to estimate the current levels of genetic variability of local cultivars through the use of molecular markers (Amplified Fragment Length Polymorphism—AFLP). We chose to collect in two distinct micro regions in order to identify possible influences of geographic isolation and different levels of market requirements in the conservation of the genetic variability of the C. maxima. For the molecular analysis, bulk samples of fresh leaves of 15 plants/half-sibling family were collected in paper bags. There were 34 samples from the half-sib families. The analysis of the results half-sib obtained by methods of estimation of genetic variation by molecular markers shows that the forms of cultivation and management adopted by family farmers maintain the identities of the local/landraces (native cultivars) and, at the same time, the levels of diversity for the assurance of adaptability macro-environmental.