Coffee leaf rust is the most limiting disease for coffee cultivation in Brazil. Despite its importance, relatively little is known about the genetic diversity of Hemileia vastatrix , the rust causal agent. In this work, the DNA from 112 monopustule isolates from different geographic locations and coffee genotypes were analysed by amplified fragment length polymorphisms ( AFLP ). The objectives were to assess the influence of the host and geographic origin on the diversity and population differentiation in H .  vastatrix . The fungal population showed a low level of genotypic diversity. Gene diversity ( h ) was 0·027 and the hypothesis of random mating in the total population was rejected, but evidence for recombination was found for two subpopulations (São Paulo and Paraná). The analysis of molecular variance revealed that 90% of the genetic distribution of the pathogen occurs among isolates within the subpopulation (states or host of origin). There was no correlation between geographic and genetic distance ( r  = −0·024, P  =   0·74), which together with the high number of migrants and the low degree of differentiation in populations of H . vastatrix , is consistent with the fact that the inoculum is probably easily dispersed by wind over long distances, allowing dispersal of the pathogen among coffee growing areas in Brazil. Therefore, it is difficult to predict the durability of resistant sources to coffee rust. The recommendation for the breeding programmes is thus to incorporate multigenic resistance as a control strategy.

Cassava is a staple food for African, Latin American and Asian countries, and is used as a source of raw material for the starch and ethanol industry (Pinweha et al. 2015). Anthracnose is one of the most important diseases which may lead to plant death. In May, 2014, necrotic and irregular shaped spots, and sunken lesions on fruits and stems, were observed on plants in a commercial field from the Aliança Cooperativa do Amido – COOPAMIDO [located at Laje (BA), Brazil, 13° 6' 34.7" S, 39° 16' 42.4" W]. A total of 15 isolates were obtained, and two strains (PPAM10 and PPAM13) were used for the characterization procedure. The isolates grew on potato dextrose agar (PDA) and synthetic nutrient-poor agar (SNA) medium at 25°C and 12-h of light. On PDA, the colonies were white to gray on the upper surface and orange to gray on the reverse side, after seven days. On SNA, the conidia were cylindrical to subcylindrical, hyaline and guttulate, with 16.7 to 23.3 (x̅= 20) × 5.1 to 7.5 (x̅= 6.2, n = 50) µm. Conidia lengt...