Leaves of barley plants were mechanically inoculated with barley mild mosaic virus (BaMMV) and roots were inoculated using viruliferous zoospores of the fungus vector Polymyxa graminis. At intervals after inoculation, leaves and roots were tested by different methods to detect virus coat protein (ELISA or Western blot) or nucleic acid (slot-blot or reverse transcriptase-PCR) . Following inoculation with zoospores, virus could be detected in roots after 1 wk (Western blot or PCR) but not until 3-4 wk by ELISA. Virus moved to leaves in 5-6 wk but, except at temperatures of about 20°C, plants had to be cut back close to soil level to stimulate virus movement. Following mechanical inoculation, virus could be detected in leaves of a susceptible cultivar within 5 days by ELISA and 3 days by the other methods. Western blots and PCR showed that virus was present in the roots by 5 days. BaMMV was not detected by any method in leaves or roots of a resistant cultivar, indicating that the virus did not multiply in it. When leaves were mechanically inoculated on a small area only, BaMMV capsid protein was detected below the inoculated site at 4 days and in young growing leaves and roots at 13 days after inoculation but never above the inoculation site or in older leaves. After stem extension began, new leaves of infected plants were free of symptoms. The results are compared to observations of plants infected with barley yellow mosaic virus (BaYMV). It is proposed that movement of BaMMV and BaYMV is strongly related to the phloem transport and to the source-sink pattern of winter barley plants.

The distribution of two UK strains of barley yellow mosaic virus has been studied and both have been transmitted experimentally by Polymyxa graminis. cDNA hybridization studies support the suggestion that the strains should be considered distinct viruses. Oat mosaic and oat golden stripe (OGSV) viruses also occur in the UK. OGSV is a furovirus related to wheat soil‐borne mosaic furovirus: it has particles of two lengths and a bipartite genome.

Quarantine Service interception of virus in imported meristem cultures of banana In 2003, banana (Musa sp.) producers located in the Northeast Region of Brazil imported a great number of micropropagated banana plantlets with the objective of enhancing production for exportation and internal consumption. Although it is an important activity for agribusiness, these importations can introduce and/or spread exotic and economically important pests to Brazil, causing serious damage to our agriculture. With the objective of minimizing the risk of virus introduction, representative samples from a group of 140,000 banana buds imported from Costa Rica were analyzed by ELISA tests at the Quarantine Laboratory of Embrapa Genetic Resources and Biotechnology (Cenargen). Banana bract mosaic virus, which is an exotic virus to Brazil and Banana streak virus were detected in the analyzed material. Although the acquisition of new genotypes is very important for the implementation of banana production in Brazil, it is shown here that the risk of introduction and dissemination of viruses associated with the material is real, and therefore, the need of phytosanitary measures to minimize those risks must be emphasized.

A pupunheira é uma palmeira tropical com vasta distribuição na região Amazô-nica, que em seu estado adulto atinge até 20 m de altura (Camacho, 1972) seus frutos possuem um alto valor nutritivo e sà"o muito apreciados pela população manauara. Porém o cultivo desta espécie na região amazônica é dificultado por sérios problemas fitossanitários.Em 1980, constatou-se em plântulas de pupunha, em viveiro, a ocorrência de manchas foliares irregulares de contornos nítidos, iniciando-se normalmente nas bordas e acentuando-se para o centro da área foliar. Os tecidos necrosados apresentavam uma coloração escura. As plantas mais jovens mostram uma seca e queima dos foliolos, provocando às vezes a morte das plantas. De folhas atacadas isolouse o patógeno em meio BDA (BatataDextrose -Agar). Após obtenção de culturas puras do fungo, este foi multiplicado. Oito dias após o isolamento do fungo, efetuou-se a trituração de 1 placa de BDA contendo o fungo em 100ml de água destilada estéril. A suspensão foi Inoculada por "aspersão" em 05 plantas previamente feridas com auxílio de um estilete, com aproximadamente dois meses de desenvolvimento, e 05 plantas sem ferimentos, sendo mantidas 05 plantas feridas para o controle. As plantas foram mantidas em câmaras úmidas por 48 horas à 28-30°C.Uma semana após a inoculação constatou-se sintomas semelhantes aos anteriormente citados nas plantas inoculadas com ferimento. O fungo foi isolado e identifi-