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Estimates of genetic parameters and correlations between phenological and morphological traits in cowpeaDetermining the genetic variability and correlations between traits of interest for selection in a population is one of the stages in a breeding program. The objectives of this study was to evaluate the potential for genetic improvement of a population composed of 19 cowpea genotypes of erect and semi-erect growth habits, involving commercial varieties and advanced lines. Genetic and phenotypic parameters and correlations between phenological and morphological traits of the population were estimated. The trial was carried out at the experimental field at the Universidade Estadual de Mato Grosso do Sul, in Aquidauana, in the dry season of the crop year 2007/2008. The following traits were evaluated: days to flowering (DF), days to maturity (DM), mass of 100 beans (MHB), length of pod (LP), mass of pods (MP), number of seeds per pod (NS) and dry bean yield (DBY). There was a significant effect Mensurar a variabilidade genética e conhecer as correlações entre caracteres de interesse para seleção numa população constitui uma das etapas iniciais em um programa de melhoramento genético. Com o objetivo de avaliar o potencial para o melhoramento genético de uma população composta por 19 genótipos de feijão-caupi de porte ereto e semiereto, entre variedades comerciais e linhagens avançadas, foram estimados parâmetros genéticos e fenotípicos e correlações entre caracteres fenológicos e morfoagronômicos da população. O experimento foi conduzido na área experimental da Universidade Estadual de Mato Grosso do Sul, em Aquidauana, no período da seca do ano agrícola 2007/2008. Foram avaliados os caracteres: dias para o florescimento (DF), dias para a maturação (DM), massa de 100 grãos (MCG), comprimento de vagem (CV), massa de vagem (MV), número de grãos por vagem (NGV) e produtividade de grãos secos (PROD). Verificou-se efeito significativo de genótipos para todas as características indicando existên-cia de variabilidade. O maior valor da estimativa do coeficiente de variação genética foi obtido para PROD, que também apresentou o mais alto valor de coeficiente b, 2,05, indicando condição favorável para seleção desse caráter. Dentre os demais caracteres apenas para DM o valor do coeficiente b foi superior a um. Foram observadas correlações genéticas positivas e significativas entre todos os caracteres e PROD, sendo as mais elevadas com DF, MV e NGV. Concluiu-se que a população apresentou potencial para o melhoramento genético e que aumento da produtividade de grãos pode ser obtido principalmente para genótipos mais tardios. Palavras-chave:Vigna unguiculata (L.) Walp, parâmetros fenotípicos, variabilidade genética. 89Estimativas de parâmetros genéticos e correlações entre caracteres fenológicos e...Rev. Ceres, Viçosa, v. 59, n.1, p. 88-94, jan/fev, 2012

The Brazilian savanna is the second largest ecosystem in Brazil. It is also one of the most endangered, with only 20% of its habitat remaining unchanged. Agriculture and livestock have been indicated as the main agents of destruction of the Brazilian savanna. Brazilian livestock, for example, is the main reason for cultivation of exotic grasses such as Urochloa spp. (from Africa). Dung beetles are widely used in ecological assessment, mainly because they are recognized as bioindicators of environmental changes. Therefore, efficient sampling is required for any research involving the biodiversity of this group. In order to mitigate the lack of information on efficiency of the attractiveness of baits in the endangered Brazilian savanna and in exotic pasturelands, we sampled dung beetles in four native patches of the Brazilian savanna and in four areas of pastures with Urochloa spp. Dung beetles were captured with pitfall traps baited with carcass, cattle dung, human feces and pig dung, with a total sampling effort of 384 traps. We sampled 7544 individuals belonging to 43 species and 18 genera of dung beetles. Thirty‐eight species were collected in the Brazilian savanna and 24 species in exotic pastureland. In both ecosystems traps baited with human feces sampled greater abundance and species richness of dung beetles when compared with the other three baits used. Our results showed that human feces is a reliable, easy and inexpensive bait to sample greater abundance and species richness of generalist dung beetles in both native and exotic habitats, with clear structural differences.

1. Dung beetles perform relevant ecological functions in pastures, such as dung removal and parasite control. Livestock farming is the main economic activity in the Brazilian Pantanal. However, the impact of cattle grazing on the Pantanal´s native dung beetle community, and functions performed by them, is still unknown. 2. We evaluated the effects of cattle activity on dung beetle community attributes (richness, abundance, biomass, composition and functional group) as well as their ecological functions (dung removal and soil bioturbation) in the Pantanal. In January/February 2016, we sampled dung beetles and measured their ecological functions in 16 sites of native grasslands in Aquidauana, MS, Brazil, 10 areas regularly grazed by cattle and six control ungrazed areas (> 20 years abandonment). 3. We collected 1169 individuals from 30 species of dung beetles. Although, abundance, species richness and biomass did not differ between grasslands with and without cattle activity, species composition and functional groups differed among systems. Large roller beetles were absent from non-cattle grasslands, while the abundance, richness and biomass of medium roller beetles was higher in those systems. 4. Despite causing changes in species/functional group composition, our results show that a density compensation of functional groups in cattle grazed natural grasslands seems to have conserved the ecological functions (dung removal and soil bioturbation), with no significant differences between systems. 5. Therefore, our results provide evidence that cattle breeding in natural grasslands of the Brazilian Pantanal can integrate livestock production with the conservation of the dung beetle community and its ecological functions.

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Grazing by large herbivorous mammals is still a structuring force in tropical grassy ecosystems, and cattle grazing is one of the main economic activities carried out in these ecosystems in modern times. Therefore, understanding the impacts of cattle grazing removal on biodiversity may be a key step for conservation of this ecosystem. Here, we studied the successional trajectory of dung beetle communities in a tropical grassy ecosystem after cattle removal. For this, we assessed the patterns of dung beetle taxonomic and functional diversity of 14 natural grasslands with distinct cattle grazing removal ages (from 3 months to 22 years) along a chronosequence, applying the space-for-time substitution method. Our results show a strong decrease in dung beetle abundance (93 times) and species richness (6 times) in the first ten years of cattle removal. However, after ten years there is an increase in dung beetle abundance (73 times) and species richness (5 times). Taxonomic composition was also influenced by cattle removal time demonstrating the importance of cattle in the structuring of dung beetle communities in natural grasslands. In contrast, functional composition and diversity were not affected by cattle grazing removal, indicating these metrics are less sensitive to cattle absence than taxonomic diversity and composition. Our results provide evidence that cattle grazing removal, at least in the short term (10 years), may be an inefficient management tool for restoration and conservation of tropical grassy ecosystems. However, we highlight the need to investigate the reintroduction of cattle grazing after different removal times to provide complimentary information to livestock management able to integrate human use and conservation of tropical grassy ecosystems.

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Dung beetles are globally used in ecological research and are useful for assessing the effects of anthropic and natural changes in environment on biodiversity. Here we investigate how the choice of baits (human feces, cattle dung, carrion or a combination of all three) and sampling season influence the taxonomic and functional diversity of insects captured in traps in Brazilian pastures. We sampled dung beetles in July 2011 (dry season) and January 2012 (rainy season) in eight areas: four pastures with native grasses (e.g., Andropogon spp. and Axonopus spp.) and four pastures with introduced grasses (Urochloa spp.) in Aquidauana, Mato Grosso do Sul, Brazil. To collect the insects, we used pitfall traps baited with carrion, cattle dung and human feces. A total of 7,086 dung beetles of 32 species were captured. In both pasture types, only traps baited with human feces captured similar abundance, species richness, and functional diversity compared with the sum total of beetles captured by the three bait types. The species richness and functional diversity were higher in the rainy season in both pasture types. Our results demonstrate that using human feces alone as bait and sampling dung beetles in the rainy season are potentially sufficient to ensure the greatest number of functional traits, species, and individuals in both pasture types. Thus, the best sampling method observed in this study may be useful for studies focused on dung beetle fauna survey and rigorous comparison among studies on these insects in Brazilian pastures.