Ivandilson Pessoa Pinto de Menezes

Distância genética entre linhagens avançadas de germoplasma de algodão com uso de marcadores de RAPD e microssatélites

The objective of this work was to select similarity coefficients to be used among sets of cotton genotypes with low genetic diversity. Sixty-five lineages and four cotton cultivars were analyzed by RAPD and SSR markers; and the genetic similarity was estimated by seven similarity coefficients: Simple Matching, Rogers & Tanimoto, Ochiai, Hamman, Jaccard, Dice and Russel & Rao. The adequacy of the use of each coefficient to the collected data was verified by correlation between the distance matrices, the consensus index between the dendrograms and the Tochers optimization method. The coefficient of Russel & Rao was the most divergent, and its use is not recommended. Among the parameters used to estimate the quality of information provided by each coefficient, differences were observed only by the consensus index, which established two groups: one in which simultaneous absence of bands are taken into account, and other in which it is excluded. Considering the presence of only two microsatellite alleles per polymorphic locus and the higher consensus index coefficients, the Simple Matching, Hamman and Rogers & Tanimoto coefficients should be preferred when analyzing cotton elite genotypes with low genetic similarity.

Biotools: an R function to predict spatial gene diversity via an individual-based approach

The gene diversity or expected heterozygosity (HE) is based on the allele frequency and is often used as a measure of genetic variability of populations. Knowing the pattern of spatial distribution of HE can be useful for determining strategies of conservation and sampling of collections of individuals. In addition, it can allow one to detect genetic boundaries in a landscape. We adapted a Wombling method based on assignment tests in a circular moving window extensively sampled over the study area in order to estimate HE at points of a prediction grid. The function sHe(), package biotools, is an easy-to-use and flexible implementation in R language that accepts as input geographical and genotyping data. The package biotools is distribution-free under the GPL-2/3 license and currently available from the Comprehensive R Archive Network (CRAN) at . The R platform and all R dependencies are similarly available from CRAN.

Genetic diversity of Gossypium barbadense from the central Brazilian Amazon

The Amazon Basin is a center of diversity of Gossypium barbadense and the strategy for conservation of this genetic resource depends on the knowledge of the diversity maintained in Amazonas State. During two expeditions, in 2012 and 2014, plants were collected in ten municipalities in the state of Amazonas, in the central Brazilian Amazon region. The molecular diversity was estimated by SSR markers for 50 samples collected in 2012. The morphological diversity of 24 plants collected in 2014 was assessed ex situ and compared to that of 50 plants of the same and other cotton varieties from other Brazilian states. Most of plants evaluated in situ in Amazonas had purple petioles and veins (82%), associated to medicinal use, and kidney seeds (78%). The ex situ morphological analysies showed that G. barbadense plants from the Amazonas state: i) presented higher similarity to cotton plants from other northern Brazilian states, and ii) were grouped separately from those of other northern Brazilian states by descriptor analysis. Both the molecular (H=0.41) and morphological (H=0.38±0.02) diversity among the collected plants was considered intermediary. Our study indicates the distinctiveness of Amazon cottons, and contributes to demonstrate the discrimination power of multicategorical traits.