ABSTRACT
Forage crops occupy large areas of tropical pastures for cattle feeding in Brazil. The use of stylos (Stylosanthes spp.) in these pastures, which are leguminous shrubs, has increased in the country due to their outstanding nutritional value and for being an efficient and alternative source for nitrogen fixation in the soil. In recent years, virus-like mosaic symptoms on S.guianensis leaves have often been observed in the field, indicating possible virus-like pathogen infections. In an effort to identify the causal agent, virus semi-purification protocol was performed using symptomatic S. guianensis leaves collected at EMBRAPA Beef Cattle Research Center. Total RNA extracted from this semi-purified preparation was submitted to high-throughput sequencing, which revealed complete genome sequences of novel viruses of the family Potyviridae. These viruses, tentatively named stylo mosaic-associated virus 1 (StyMaV-1) and stylo mosaic-associated virus 2 (StyMaV-2), shared 73 % CP aa identity and 77 % polyprotein aa identity with each other and, after that, being closest related to blackberry virus Y, genus Brambyvirus (only 41 % CP aa identity). Based on ICTV genus demarcation criteria, StyMaV-1 and StyMaV-2 represent new species of a new genus within the family Potyviridae. StyMaV-1 and StyMaV-2 are also not efficiently transmitted to other plant species by mechanical inoculation.
Subject(s)
Potyviridae , Animals , Brazil , CattleABSTRACT
Objetivou-se com este trabalho conhecer as espécies de parasitóides associados às pupas de Anastrepha sp., em cultivos de goiabeira Psidium guajava L. no município de Lavras - MG. Frutos atacados foram depositados em recipientes plásticos, sobre uma camada de areia fina com 5 cm de espessura, a qual serviu como substrato para a fase de pupa. As pupas foram separadas do substrato pelo método de flutuação, sendo quantificadas e individualizadas em frascos de vidro contendo areia, onde permaneceram até a emergência das moscas adultas ou de seus parasitóides. Foram coletados 190 pupários de Anastrepha sp., dos quais emergiram 38 parasitóides (Hymenoptera: Figitidae), sendo 20 Aganaspis pelleranoi (Brèthes, 1924) e 18 Dicerataspis sp., correspondendo a um parasitismo natural de 20 por cento.
The aim of this work was to search about the parasitoids species associated to Anastrepha sp. pupae on guava Psidium guajava L. groves in Lavras, MG - Brazil. Fruits with signs of infestation, including oviposition punctures, were picked and placed in plastic containers, under a layer of thin sand, which was utilized as environment for the pupae phase. The pupae were individualized on glass vials containing sand and the emerged fruit flies or theirs parasitoids were collected. A total of 190 Anastrepha sp. Pupae was obtained from which emerged 38 parasitoids (Hymenoptera: Figitidae), being 20 of Aganaspis pelleranoi (Brèthes, 1924) and 18 of Dicerataspis sp., corresponding to a natural parasitism of 20 percent.
