Estudo morfológico e histoquímico do intestino médio de larvas de Anticarsia gemmatalis (Hübner 1818) (Lepidoptera: noctuidae) suscetíveis e resistentes ao AgMNPV alimentadas com genótipos de plantas resistentes a insetos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

The velvetbean caterpillar, Anticarsia gemmatalis (Lepidoptera: Noctuidae) is a pest of soybean. To control this insect have been employed as technical biological control by nucleopolyedrovirus (AgMNPV) and the resistance of plants with cultivars that have a complex of chemicals (flavonoids), wich can make them toxic to insects. The midgut is considered the virus entry and perfomance of defense substances present in the genotypes resistant. Flavonoids such as rutin and genistein can act in the formation of fatty acids by the hydrolysis phospholipid membranes, altering the barriers and permeability of cell membranes. Apparently rutin and genistein causes causes of inhibition in insects and larvae of A. gemmatalis has effect antibiosis and decreased survival. Furthermore, studies have demonstrated that rutin and genitin in larvae of A. gemmatalis resistant virus AgMNPV has increased mortality compared to larvae susceptible. This study describes the morphology of the midgut of larvae A. gemmatalis susceptible and resistant AgMNPV by light microscopy and scanning electron microscopy after treatment with different soybean genotypes with rutin and genistin in different concentrations. The midgut in both larval population is composed of peritrophic membrane, epithelial cells with three types cell (columnar, globet and regenerative) and muscle layer. The epithelial layer showed changes morphological mainly in columnar cells, with intense vacuolation presence empty and increased cytoplasmic protusions released to the lumen. Larvae are susceptible to these changes evident in the genotype PI 227687 consisting of R= 36.82x10-2mg/g and G= 1.22x10-2 mg/g. In the resistant larvae changes are evident in IAC 100 compound by R= 9.72x10-2 mg/g and G=1.42x10-2 mg/g and PI 227687 consisting of R= 36.82x10-2mg/g and G= 1.22x10-2 mg/g. The analysis in scanning electron microscopy the midgut is composed of three distinct regions, anterior, medial and posterior, and differentiated by intensity of cytoplasmic projections. These projections increased in concentration in both larval populations after treatment with genotypes composed Dowling R= 4.29x10-2 mg/g and PI227687 consisting of R= 36.82x10-2 mg/g and G= 1.22x10-2 mg/g. After the technical histochemical became evident that the cells are composed of polysaccharides, glycogen, proteins and lipids. The highest concentrations of these compounds were evidenced in the midgut of susceptible larvae and resistant after treatment with genoptype PI 229358, IAC 100 and PI 227687. Thus the genotypes IAC 100 and PI 227687 are recommended for planting because they had resistance to the larvae and also promote the breakdown of reistance in resistant larvae of A. gemmatalis.

ASSUNTO(S)

pest resistance lagarta da soja soybean caterpillar anticarsia gemmatalis - intestino médio - morfologia soja - resistência aos insetos soybean

ACESSO AO ARTIGO

Documentos Relacionados