REACTION OF SOYBEAN GERMPLASM TO Phakopsora pachyrhizi IN THE FIELD

Abstract

Asian soybean rust (Phakopsora pachyrhizi), appeared in México in 2005. Commonly sowed commercial cultivars have shown susceptibility to the pathogen, therefore this study searched for sources of genetic resistance to the disease by field evaluation of 197 soybean genotypes. Plants were sowed at two planting dates (24-Feb and 24-Apr, 2007) and inoculated during flowering initiation. Disease severity was measured during the R6 stage, using a rating scale from 1 (0 %) to 3 (> 30 %). Twenty-three soybean genotypes were identified as resistant to P. pachyrhizi and did not show leaf damage at either planting date.