Expressão de genes em plantas de soja sob infecção pela ferrugem asiática e efeito do controle químico na qualidade de sementes

Abstract

Soybean crop is affected by several diseases, especially asian soybean rust caused by Phakopsora pachyrhizi. The action of this pathogen leads to yield losses, as well as, reduction in seed quality. Furthermore, fungicide applications needed to control the disease, increase production costs and can cause a residual effect on plants, which can affect the seed physiological quality. This study was divided into two chapters. The first is “Differential gene expression in response to asian soybean rust by cDNA-AFLP technique” that aimed at identifing genes associated with soybean rust resistance in the cultivar (PI459025), which has Rpp4 resistance genes. The second chapter is “Fungicides used to control asian soybean rust and the effect on seed quality” that aimed at evaluating the effect of fungicides used to control soybean rust in the seed physiological and sanitary qualities. One hundred and forty one cDNA fragments differentially expressed between inoculated and not inoculated soybean plants were isolated by cDNA-AFLP. This strategy allowed the identification of pathogen resistance genes which can be strong candidates to asian soybean rust resistance. In relation to fungicides used to control asian soybean rust, they did not affect seed physiological quality.