Broad-sense heritability and variance component estimates for Pratylenchus brachyurus resistance in Brazilian soybean genotypes

Abstract

Pratylenchus brachyurus has become one of the most serious problems in Brazilian soybean fields. The use of resistant cultivars has long been considered the most practical and effective means of controling nematodes. Nonetheless, to our knowledge, there is no study on the genetic parameters associated with resistance of soybean to P. brachyurus in Brazil. This study was undertaken to estimate resistance genetic parameters under glasshouse conditions. In both trials, we found high phenotypic and genotypic variability, either for reproductive factor or number of nematodes per fresh gram of roots. Furthermore, high coefficients of genotypic determination and variation index were obtained. These results suggest that breeding for this feature can be relatively easy. The next logical step will be to conduct inheritance genetic studies.