Meloidogyne spp. populations from native Cerrado and soybean cultivated areas: genetic variability and aggressiveness

Abstract

A significant portion of the Cerrado (Brazilian savanna) has been replaced by major crops such as soybean. This may reveal populations of nematodes with different genetic backgrounds compared to cultivated fields. The objectives of this study were to evaluate the genetic variability and aggressiveness of isolates ofMeloidogynespp., contrasting nematodes from preserved areas of the Cerrado with those originating from cultivated soybean fields. Cluster analysis separated isolates ofMeloidogynespp. and isolates from Cerrado and soybean but did not separate an aggressiveMeloidogyne morocciensisisolate. The aggressiveness of six selected populations ofMeloidogynespp. from Cerrado and soybean against soybean cultivars was evaluated. Results showed that populations ofM. javanicaandM. incognitafrom Cerrado and soybean showed similar aggressiveness. However, forM. morocciensis, the population from soybean was much more aggressive than the one from Cerrado. Aggressiveness is a very intriguing subject that needs special attention for future research in nematology.