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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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