Variação genética para caracteres anatômicos e retração volumétrica e sua correlação com a densidade básica da madeira em uma população base de Eucalyptus camaldulensis Dehn

Eucalyptus camaldulensis has great importance in Brazil because of their phenotypic plasticity for different environmental conditions, as soils, altitudes and rainfall. This study is an investigation of a base population of E. camaldulensis from Australia through a progeny test implanted in Selvíria, MS. The trial was established in a randomized block design, with 25 families and 60 replications of single tree plots. Genetic parameters for anatomic traits and volume shrinkage were estimated, as well as their correlations with wood basic density. No significant differences among progenies were observed for the traits studied. The additive genetic variation coefficient at individual and among progeny levels ranged from low (0.26%) to high (16.98%). The narrow sense heritability at individual and family means levels also ranged from low (0.01) to high (0.87). This indicates that some traits are under strong genetic control and can be improved by selection. In the present situation, in order to attain the highest genetic gains, the sequential selection among and within progeny would be recommended.

Variação genética para caracteres silviculturais e anatômicos da madeira em progênies de Myracrodruon urundeuva (Engler) Fr. Allem

The aims of this study were to evaluate the variation and to estimate genetic parameters for silvicultural anatomic wood traits for genetic breeding of a Myracrodruon urundeuva (Engler) Fr. Allem, population from Selvíria-MS. For this, from samples of a progeny test established in the Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia de Ilha Solteira/UNESP, macroscopic anatomic wood traits of M. urundeuva (tangential diameter and vases frequency per mm2) and growth traits were measured (height, DBH and stem form). Genetic parameters were estimated in 28 open-pollinated progenies, in three replications and 10 plants per plot, using a REML/BLUP approach. Between the analysed traits, the DBH is the most indicated for selection for timber production, because it presented the highest values of coefficient of genetic variation, heritabilities and selective accuracy. Between the anatomic traits, the vessels frequency in the pith showed the highest values for genetic parameters. For pulp yield, based on the multi-effect index, the strategy of selecting the best trees for vessels frequency in the pith, independent of the progeny, permitted to obtain substantial gains by mass selection, without progeny test.

Comportamento e variação de procedências de Corymbia citriodora em diferentes tipos de solos

The aim of this study was the selection of Corymbia citriodora provenances for three different kinds of soils occurring in Luiz Antônio Experimental Station, São Paulo, Brazil (Latossolo Vermelho, Areia Quartzosa and Latossolo Roxo). The provenance test was established in 1983, with ten Corymbia citriodora provenances and one Eucalyptus grandis as control, original from a seed production area. The trials were established in a random block design with 11 treatments, three repetition and square plots with 25 trees. In 2008, there were evaluations of height, diameter at breast height (DBH, 1.3 m), stem form and survival. Significant differences among soils and provenances were detected for the growth traits, stem form and survival in all those studied soils. Significant provenance and soil interactions were not detected. All provenances showed higher growth in height and DBH in Purple Latosol. The control had a higher growth rate in relation to highness, DBH and stem form than Corymbia citriodora provenances in all the studied soils, but it presented, generally, a lower survival rate than Corymbia citriodora provenances. Pederneiras (11) Corymbia citriodora provenance presented a higher performance in relation to highness and DBH in all kinds of soils, and Gilgandra (4) provenance, original from Australia, had the worst development. Therefore, Pederneiras (11) provenance is, therefore, the best choose for reforestations in all those studied soils.

Focando na variação: Métodos e aplicações do conceito de diversidade beta em ecossistemas aquáticos

Ecologists usually estimate means, but devote much less attention to variation. The study of variation is a key aspect to understand natural systems and to make predictions regarding them. In community ecology, most studies focus on local species diversity (alpha diversity), but only in recent decades have ecologists devoted proper attention to variation in community composition among sites (beta diversity). This is in spite of the fact that the first attempts to estimate beta diversity date back to the pioneering work by Koch and Whittaker in the 1950s. Progress in the last decade has been made in the development both of methods and of hypotheses about the origin and maintenance of variation in community composition. For instance, methods are available to partition total diversity in a region (gamma diversity), in a local component (alpha), and several beta diversities, each corresponding to one scale in a hierarchy. The popularization of the so-called raw-data approach (based on partial constrained ordination techniques) and the distance-based approach (based on correlation of dissimilarity/distance matrices) have allowed many ecologists to address current hypotheses about beta diversity patterns. Overall, these hypotheses are based on niche and neutral theory, accounting for the relative roles of environmental and spatial processes (or a combination of them) in shaping metacommunities. Recent studies have addressed these issues on a variety of spatial and temporal scales, habitats and taxonomic groups. Moreover, life history and functional traits of species such as dispersal abilities and rarity have begun to be considered in studies of beta diversity. In this article we briefly review some of these new tools and approaches developed in recent years, and illustrate them by using case studies in aquatic ecosystems.

Fluorescência da clorofila-a e variação da simetria como ferramentas de investigação de plantas sob estresse

Environmental disturbances in various systems and individuals can result in a tendency for fluctuating asymmetry, which consists of a non-directional deviation from symmetry of a bilateral structure in a normally distributed population. Individuals unable to exhibit plastic responses to developmental disorders that occur at random, either genetic or environmental, may exhibit slight deviations from symmetry in organs with bilateral structure such as leaves. Thus analyzing plants by the morphological pattern of symmetry of the leaves has become an effective tool to describe the developmental of plants under stress conditions. This study aimed to analyze if the pattern of symmetry can be used as a tool to investigate the stress level to which a plant is subjected, using ultraviolet-C radiation (UV-C) as source of stress. We determined the leaf symmetry deviations (sd), the average length (AL) and the maximum width of the lamina (MWL) and the fluorescence parameters of chlorophyll-a in leaves of young plants of G. max subjected to 0, 30, 60, 120 or 240 minutes per week of UV-C during four weeks, submitting the values to ANOVA and Tukey test (p <0.05). The results showed significant reductions in AL and MWL, significant increase in sd in leaves irradiated and a drop in potential quantum yield of photosystem II (PSII) and in the photosynthesis performance index (IP). The analysis of leaf symmetry showed high correlation with the stress level to which plants were submitted, being an important analysis to ascertain the fitness of the plant because it is a noninvasive method and easy to perform.

Variação e parâmetros genéticos em teste de progênies de polinização livre de Peltophorum dubium (Sprengel) taubert em Luiz Antonio -SP

Intensive deforestation and forest fragmentation of the Brazilian forest biomes has contributed to increase the number of trees species under the risk of extinction. Peltophorum dubium (Sprengel) Taubert is one of these species. Some of its populations are being conserved ex situ by the Instituto Florestal de São Paulo through provenance and progeny tests. The aim of this study was to investigate the genetic variation and to estimate genetic parameters at age 24 years in a progeny test of P. dubium established in Luiz Antônio, São Paulo State, Brazil. The trial was established in a random block design, with six replications, five plants per plot and 18 open-pollinated progenies. Measured were: diameter at breast height (DBH), height and stem form. The genetic parameters heritability, genetic variation and effective population size were estimated. Significant genetic differences were observed only for DBH. This trait also presented a high coefficient of genetic variation (CV g=4.8%) and heritability, especially among progeny means (h m 2=0.6607). This indicates that DBH is the most indicated trait for selection in the population. The effective population size conserved ex situ in the test was estimated to be 38.9. Concerning genetic conservation, although the effective population size in the test is small, the values of the genetic variation and of the heritability indicate that the ex situ population has sufficient genetic variation and potential to respond to changes promoted by natural and artificial selection.

Variação sazonal da comunidade protozooplanctônica em um ambiente oligotrófico tropical (reservatório de Ilha Solteira, Brasil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variação entre a lâmina de irrigação aplicada e armazenada no solo sob condições de irrigação com baixa uniformidade de distribuição de água

In sprinkler irrigation is important to have a good uniformity of application so that the water in the root zone does not show areas with little available water while others have percolating beyond the plant roots, even though the soil allows a lateral redistribution of water. A usual way to obtain the uniformity of irrigation is by measures of dispersion. The aim of this work was to evaluate the uniformity of water stored in a sand soil before and after non uniformity depth irrigation applied from one sprinkler, as well the variation of storage in a 0-0,45 m layer soil using a neutron probe. The statistical design was completely randomized, and for the variable Christiansen uniformity coefficient modified (CUCHH) were 10 treatments (the irrigation depth, 8 intervals of readings storage, more the existing one before irrigation added to the irrigation depth). For the variable soil water, the treatments were the same, excepting the irrigation depth. Despite the low surface uniformity (16.3%), there was not significantly difference between the storage uniformity before, after irrigation and the potential, however there was from these to the surface uniformity. From de irrigation depth, 15.3 mm, only 6.1 mm remained in the layer from 0 to 0.45 m. There was not significantly difference between the water stored in the soil before and after irrigation within a period of up to 134 hours, being the increase in storage due to irrigation was just 11.7%.

Variação genética em progênies de jacaranda cuspidifolia mart. Utilizando o delineamento sistemático tipo leque

Knowledge of genetic variation in native tree species has helped direct strategies of genetic ex situ conservation, based on provenances and progenies tests. These tests use fixed spacing, not allowing evaluating the behavior of different progenies under this management variable. One way to evaluate simultaneously the genetic variation and different spacing in a small planting area is to use a systematic design. The aim of this study was to estimate the genetic variation and to evaluate its performance in Jacaranda cuspidifolia under different spacing. We used a progeny test in a systematic fan design, arranged in a system of 30 concentric rays, with one progeny per ray, randomly, at angles of 12°. The plants were arranged in rays in geometric progression of ratio 1.21, corresponding to nine for plant spacing: 1,95 m2; 2,86 m2; 4,18 m2; 6,12 m2; 8,96 m2; 13,12 m2; 19,21 m2; 28,13 m2; e 41,19 m 2 installed in Selvíria/MS. The traits height, height diameter of 30 cm to soil (DA3) and survival were evaluated at 12 and 24 months of age. Estimates of genetic parameters and spacing were evaluated using the procedure REML/BLUP (restricted maximum likelihood / best linear unbiased prediction). The progenies showed genetic variation, showing that the sample strategy to ex situ conservation was efficient. The species showed good adaptability inthe field and the best performance in treating five, equivalent to a 3 × 3 m spacing, with 8,96 m2;/plant for all traits. The fan systematic design permitted to evaluate in a small area the silvicultural behavior of J. Cuspidifolia plants in spacing varying from 2 to 42 m2/plant (5.000 to 238 trees/ha); which could hardly be evaluat by the traditional designs.

A variação de pluralidade nas estruturas predictaivas da variedade falada na região de São José do Rio Preto

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variação lexical e sintática na produção escrita formal do português em Moçambique

Pós-graduação em Estudos Linguísticos - IBILCE

Variação da pressão sistólica como indicadora precoce de hipovolemia e guia de reposição volêmica com solução hiperosmótica e hiperoncótica no cão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variação no tamanho corpóreo e cantos de anúncio de hilídeos (ANURA) na Serra do Mar

Pós-graduação em Biologia Animal - IBILCE

Variação espacial nas interações entre o palmito Euterpe edulis e as aves frugívoras: implicações para a dispersão de sementes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Variação intra-específica na fenologia de espécies de sub-bosque de floresta Atlântica e sua relação com variáveis microambientais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)