RESUMO
ABSTRACT Understanding aspects of insect ecology is a key component for the applicability of control methods or pest resistance management. For instance, the comprehension of insect dispersal is crucial to determining insect gene flow and the maximum distance between refuge areas in Bt (Bacillus thuringiensis) crops. But, for such studies, insects need to be marked prior to release. Seeking to refine the technique of dispersion studies of the genetic material of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), this study aimed to determine the efficiency of water-soluble dyes for the internal marking of S. frugiperda immatures and adults via larval feeding, with emphasis on marking the spermatophore. Rhodamine B, Methylene Blue, Ponceau, Coomassie, and Eosin-Nigrosin were added to the larval artificial diet at concentrations of 0, 100, 200, 400, 600, 800, and 1000 ppm. Mortality and duration of the larval stage as well as the efficiency of marking internal structures of larvae and adults were evaluated. Rhodamine B and Methylene Blue increased the duration of the larval period, but the former caused higher mortality. The staining of the gut, hemolymph, and imaginal discs, in the larval phase, was observed for Rhodamine B, Methylene Blue, and Coomassie dyes. However, none of the dyes were efficient for marking spermatophores. Thus, the addition of these water-soluble dyes to the larval diet of S. frugiperda can mark internal structures of the larva, but not the adult. Therefore, these dyes have limited application once they may be used only for marking larvae.
RESUMO
Knowledge of genetic diversity is of great importance to the contribution of plant breeding, as it helps plant breeders to better selecting parents for establishment of segregating populations. This knowledge is especially important to crops that presents a narrow genetic base as soybean. The objective of this work was to assess agronomic performance and genetic diversity of lines and soybean cultivars, in order to find those ones with potential to be used as parents in breeding programs. Experiment was carried out during 2015/2016 season in the Federal University of Uberlândia farm known as Capim Branco. A randomized complete block designed was applied in order to assess twentythree morpho-agronomic features on twenty-four soybean genotypes. Significant genetic variability for all agronomic traits was found. Genotypes UFU B7, UFU B14, UFU B16, Msoy 6101 and UFUS 7910 were set as early maturity soybean, with life cycle duration ranging from 107.3 to 111 days. Genotypes UFU B1, UFU B3, UFU B8 and UFU B16 presented productivity values higher than national average of 2.870 kg ha-1. Genotypes were clustered by UPGMA, Tocher and canonical variables methods. Both UPGMA and Tocher methods formed four groups. NDF was the major contributor to genetic diversity. Hybridizations between UFU B3, UFU B8, UFU B16 genotypes with UFU B1 genotype might be promising for establishment of segregating populations shown superior genetic variability. Under these circumstances, it was concluded that agronomic features assessed were useful on detection of parents with potential to UFU's soybean breeding program.
O conhecimento da diversidade genética é de grande importância para o melhoramento de plantas, pois auxiliam os melhoristas na escolha de genitores para formação de populações segregantes, especialmente na cultura da soja que é de base genética estreita. O objetivo do trabalho foi avaliar o desempenho agronômico e a diversidade genética de linhagens e cultivares de soja, com potencial de serem utilizados como genitores em programas de melhoramento genético. O experimento foi conduzido em uma área experimental localizada na Fazenda Capim Branco pertencente à Universidade Federal de Uberlândia na safra de 2015/2016. Foram avaliados 24 genótipos de soja, em delineamento de blocos completos casualizados, nos quais foram avaliados 23 caracteres morfo-agronômicos. Foi verificada variabilidade genética para todos os caracteres agronômicos. Os genótipos UFU B7, UFU B14, UFU B16, Msoy 6101 e UFUS 7910 foram classificados como genótipos de ciclo precoce, com duração variando de 107,3 a 111 dias. Os genótipos UFU B1, UFU B3, UFU B8 e UFU B16 apresentaram produtividade elevadas em relação aos demais com valores superiores à média nacional, que é de 2.870 kg ha-1. Os genótipos foram agrupados pelos métodos UPGMA, Tocher e variáveis canônicas. Pelos métodos UPGMA e Tocher foram formados quatro grupos distintos. O NDF foi o caractere que mais contribuiu com a diversidade genética. Hibridações dos genótipos UFU B3, UFU B8 e UFU B16 com o genótipo UFU B1 são promissoras para obtenção de populações segregantes com variabilidade genética superior. Desse modo concluiu-se que o uso de caracteres agronômicos permitiu detectar genitores potenciais para o programa de melhoramento de soja da UFU.