Endophytic Trichoderma species from rubber trees native to the Brazilian Amazon, including four new species.

Fungi belonging to the genus Trichoderma have been widely recognized as efficient controllers of plant diseases. Although the majority of isolates currently deployed, thus far, have been isolated from soil, endophytic Trichoderma spp. is considered to be a promising option for application in biocontrol. In this study, 30 endophytic Trichoderma isolates-obtained from the leaves, stems, and roots of wild Hevea spp. in the Brazilian Amazon-were analyzed using specific DNA barcodes: sequences of internal transcribed spacers 1 and 2 of rDNA (ITS region), genes encoding translation elongation factor 1-α (TEF1-α), and the second largest subunit of RNA polymerase II (RPB2). The genealogical concordance phylogenetic species recognition (GCPSR) concept was used for species delimitation. A phylogenetic analysis showed the occurrence of Trichoderma species, such as T. erinaceum, T. ovalisporum, T. koningiopsis, T. sparsum, T. lentiforme, T. virens, and T. spirale. Molecular and morphological features resulted in the discovery of four new species, such as T. acreanum sp. nov., T. ararianum sp. nov., T. heveae sp. nov., and T. brasiliensis sp. nov. The BI and ML analyses shared a similar topology, providing high support to the final trees. The phylograms show three distinct subclades, namely, T. acreanum and T. ararianum being paraphyletic with T. koningiopsis; T. heveae with T. subviride; and T. brasiliensis with T. brevicompactum. This study adds to our knowledge of the diversity of endophytic Trichoderma species in Neotropical forests and reveals new potential biocontrol agents for the management of plant diseases.

Cercospora apii causing leaf spots on two Brazilian toxic weeds: solanum glaucophyllum and Xanthium strumarium

Samples of two toxic weeds, Solanum glaucophyllum and Xanthium strumarium, bearing leaf spots symptoms were found. Cercospora apii was found associated to these leaf spots in both plants. These are the first reports of this fungus on these hosts in Brazil and its first report on S. glaucophyllum worldwide.

Foram encontrados plantas das espécies Solanum glaucophyllum e Xanthium strumaruium apresentando sintomas de manchas foliares. Cercospora apii foi encontrado associado lesões foliares em ambas as plantas. Estes são os primeiros relatos desse fungo nestes hospedeiros no Brasil e o primeiro relato de sua ocorrência em S. glaucophyllum no mundo.

Morphological and molecular differentiation of the pectinase producing fungi Penicillium expansum and Penicillium griseoroseum

Two species from the genus Penicillium, Penicillium expansum and P. griseoroseum (Brasilian isolates) were characterized morphologic and molecularlly. Morphological variability was detected among isolates in regard to colony morphology and to conidia coloration. The molecular characterization was based on the RAPD markers, telomeric fingerprinting and ITS sequencing. A total of 78 RAPD primers were used and 8 presented differences in band patterns with 54% of the amplified polymorphic fragments. The monomorphic fragments of 600 bp (P. expansum) and 594 bp (P. griseoroseum) were amplified. The only internal transcribed spacer region variation detected between the two species was the additional six initial nucleotides. The analysis by telomeric fingerprinting showed polymorphism between both species and the chromosome minimal numbers estimated were three. The polymorphism observed in the organization of the subtelomeric region in the genome of two Penicillium species within the high homogeneous Penicillium subgenus is for the first time reported and perhaps can be employed in future phylogenetic studies.

Penicillium expansum e P. griseoroseum foram caracterizados morfológica e molecularmente. Variações na morfologia das colônias e coloração dos conídeos foram observadas entre os isolados. A caracterização molecular foi baseada em marcadores RAPD, sequenciamento da região do espaçador interno transcrito do DNA ribossomal e "fingerprinting" telomérico. Foi usado um total de 78 primers RAPD, sendo que 8 apresentaram 54% de fragmentos de DNA polimórficos. Os produtos da amplificação da região ITS de P. expansum e P. griseoroseum foram de 600 e 594 pb, respectivamente. Não foi detectada nenhuma variação na seqüência de nucleotídeos dessa região, comparando-se P. expansum e P. griseoroseum, exceto em relação aos seis nucleotídeos iniciais adicionais. Observou-se a ocorrência de polimorfismo na organização da região subtelomérica no genoma destes fungos e estimou-se um número mínimo de três cromossomos para estas espécies. Este é o primeiro trabalho que descreve a existência de polimorfismo na organização da região subtelomérica do genoma de espécies de fungos pertencentes ao gênero Penicillium, altamente homogêneo, indicando uma possível utilização da abordagem empregada neste estudo para pesquisas filogenéticas futuras.