Resumo

GARCIA-RODRIGUEZ, Julio César; MORISHITA, Mio; KATO, Masayasu  e  YAMANAKA, Naoki. Pathogenic characteristics of the Asian soybean rust (Phakopsora pachyrhizi) in Mexico. Rev. mex. fitopatol [online]. 2017, vol.35, n.2, pp.338-349. ISSN 2007-8080.  https://doi.org/10.18781/r.mex.fit.1701-5.

In Mexico, the Asian soybean rust caused by Phakopsora pachyrhizi, reduces soybean yield by 25 % to 80 %. The use of resistant cultivars is the most cost-effective strategy for management of this disease. The objective of this study was to determine the pathogenic characteristics of P. pachyrhizi populations in Mexico in order to look for effective resistance in soybean germplasm. Using 12 soybean differentials carrying 0-3 resistance genes, the pathogenic profiles of four P. pachyrhizi populations sampled in northeastern Mexico in 2015, were evaluated. Three of the populations had similar pathogenic characteristics. Cluster analysis supported the distinction by the location of two clusters of Mexican P. pachyrhizi populations apart, in the dendrogram of South American and Japanese rust populations. This indicates a large variation in the soybean rust populations in Mexico. In addition, no soybean differential carrying a single resistance gene showed resistance to all the four Mexican populations; however, the differential carrying three genes was resistant to all the P. pachyrhizi populations. Therefore, introducing multiple resistance genes in soybean breeding programs will be useful to develop rust-resistant cultivars in Mexico.

Palavras-chave : Glycine max; Phakopsora pachyrhizi; differentials; gene pyramiding; pathogenicity.