Pitch canker is one of the most important diseases of pine trees worldwide, including South America. The causal agent of this disease is Fusarium circinatum, a member of the Gibberella fujikuroi complex (GFC). In South America, the species is reported from Colombia, Uruguay and Chile, but is considered a quarantine organism in Brazil. In this study we characterized isolates obtained from symptomatic pine seedlings intercepted in a nursery in Santa Catarina State using phylogenetic analyses, crossings and morphological markers. The Brazilian isolates grouped with reference material in an unique clade and formed fertile perithecia when crossed with reference tester strains. The detailed characterization given here and the availability of tester strains will allow for reliable identification and support monitoring of this important plant pathogen.

Ramulosis of cotton, caused by Colletotrichum gossypii var. cephalosporioides (CGC), is an important disease of cotton in Brazil. The main objective of this work was to test whether CGC is a phylogenetic species inside the Colletotrichum gloeosporioides species complex. A Bayesian inference phylogenetic analysis of a combined ITS and TUB2 dataset was conducted with 21 strains identified as CGC and five strains of Colletotrichum gossypii (CG), associated with cotton anthracnose, obtained from diseased plants from different regions of Brazil. All CGC strains formed a highly supported lineage inside the clade of Colletotrichum theobromicola, a member of the C. gloeosporioides species complex. CG strains formed another lineage in the same clade. These findings were supported by a second analysis conducted with three genes (ITS+TUB2+GAPDH) and a subset of five CGC and three CG strains. During pathogenicity tests, all five CGC strains tested induced typical symptoms of ramulosis on inoculated plants, including foliar necrosis, death of apical meristems and over sprouting. Plants inoculated with CG strains exhibited foliar necrotic spots two months after inoculation. These results give phylogenetic support for the placement of CGC in the C. gloeosporioides species complex, and the distinction between the ramulosis and anthracnose pathogens of cotton in Brazil.

Members of Fusarium oxysporum species complex (FOSC) have been extensively studied because it causes many crop diseases and losses. This complex has more than 150 putatively plant host‐specific formae speciales such as F. oxysporum f.sp. cubense (Foc), the aetiological agent of Fusarium wilt of banana, Panama disease. The objective of this study was to characterize isolates obtained from rhizomes of the latundan (apple) variety of banana showing symptoms of Panama disease using morphological markers, phylogenetic analyses of the TEF‐1α and pathogenicity tests. Isolates were harvested from the states of Minas Gerais (Foc GO2), Goiás (Foc GO1 and Foc GO2A) and Bahia (Foc 807). Morphological markers of isolates observed are in accordance with the original descriptions of the F. oxysporum. Foc isolates grouped into two different lineages, and one of these is a lineage not yet recorded. Aggressiveness was assessed by a rating scale of the symptoms displayed in the shoot, rhizome and conducting vessels in latundan banana trees. The results indicated that all isolates belong to F. oxysporum f.sp. cubense, race 1. Isolate Foc GO2A proved to be more aggressive than the others. The results generated in this study contribute to knowledge of lineages diversity within Foc.

/agrariacad Basidiomycetes associated with decay of living ornamental trees. Basidiomicetos associados ao decaimento de árvores ornamentais vivas

Cotton Ramulosis (Gossypium hirsutum) is an important disease affecting cotton plantations in Brazil, and its causal agent, Colletotrichum gossypiivar.cephalosporioides(Cgc), according to the Brazilian phytosanitary authority, was considered a regulated non quarantine pest. It makes this microorganism subject to standardization in seed certification programs. The current seed health testing for detecting that pathogen in seed samples does not provide reliable results for routine analysis. On this paper, attempts were made to design specific primers for detection of Cgc associated with cotton seed. Two primer sets were selected based on the analysis of a multiple alignment of gene’s sequence encoding the glyceraldehyde 3-phosphate dehydrogenase from Cgc, C. gossypii and reference strains of the C. gloeosporioides species complex. The conserved sites unique to Cgc strains were used to design specific fragment of 140 bp. The primer specificity was confirmed by using other fungi. The primers produced a detectable band of target DNA of Cgc in all inoculum potentials of the pathogen artificially inoculated by the water restriction technique. The developed primer pair represents, therefore, a reliable and rapid mean to diagnose the Ramulosis agent in cotton seed.