Arbutoid mycorrhizae were synthesized in vitro between Arbutus unedo L. and two isolates of Lactarius deliciosus. The fungal isolates were obtained from sporocarps collected under Pinus sylvestris and in a mixed forest stand of Quercus suber and Pinus pinea. Synthesis tubes filled with a mixture of sterilized peat, vermiculite, and perlite imbibed with nutrient solution were used. Two inoculation methods using solid and liquid media were tested. Shoots from an adult selected clone of A. unedo were used after in vitro rooting by auxin dipping. After 3 months of shoots transfer to the substrate, the root systems were examined for arbutoid mycorrhizae formation and later on ex vitro conditions, 9 months after acclimatization. The inoculum treatment with liquid medium improved the mycorrhizal development for both isolates, in vitro. Sterilized substrate for plant acclimatization increased the mycorrhizal development. The arbutoid mycorrhizae were observed in vitro as well as 9 months after acclimatization. Standard arbutoid mycorrhiza features were observed: pale yellow mantle, typical cruciform appearance, Hartig net (HN), and intracellular hyphal complexes, both confined to the epidermis. L. deliciosus mycorrhizae synthetized in vitro persisted 9 months after plant acclimatization. Morphological observations were confirmed by molecular techniques.
Arbutus unedo L. is a Mediterranean species used for fruit production; it is tolerant to drought and shows regeneration ability following forest fires. Mycorrhizal plants with Tuber borchii add resilience and value. This study aims to test the effect of quercetin on mycorrhizal synthesis between T. borchii and A. unedo. Two genotypes selected for fruit production and hydric stress tolerance, were micropropagated for mycorrhizal synthesis, accomplished during ex vitro rooting in perlite, using lyophilized spores of T. borchii suspended in culture media with different quercetin levels (0–10 µM). Six months after inoculation, plants were transferred to pots and maintained in nursery. Ten and 12 months after inoculation, roots were morphological examined and molecularly characterized using ITS1-5.8SITS2 rDNA region and specific primers. Results showed that mycorrhizae establishment was dependent on studied factors (genotype, quercetin level, and culture medium) and their interaction (genotype X culture medium). Quercetin levels up to 2.0 µM favored mycorrhizae establishment and plant growth, although levels superior to 4 µM showed a toxic effect. Quercetin showed to be an efficient factor on inducing mycorrhiza thriving independent of the genotype. Morphological observations and molecular analysis confirmed the permanence of the fungus association 10 and 12 months after inoculation.
Coffee ringspot virus (CoRSV), transmitted by the tenuipalpid mite Brevipalpus phoenicis, has been found in high incidences in several regions of the state of Minas Gerais. It induces chlorotic spots on the leaves and fruits and may induce severe fall of the leaves with implication in the yield. An evaluation was made on the effects of CoRSV-infected coffee berries on the beverage quality as RESUMOA mancha anular do cafeeiro, causada pelo Coffee ringspot virus (CoRSV) que é transmitido pelo ácaro Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae), tem sido observada em altas incidências em várias regiões cafeeiras do Estado de Minas Gerais. O CoRSV causa manchas cloróticas arrendondadas ou irregulares nas folhas, caules e frutos. Foi feita uma avaliação do efeito da infecção de frutos do cafeeiro pelo CoRSV na qualidade da bebida por meio de teste bioquímico e de degustação, e também na eventual perda de peso nos grãos. Testes revelaram que grãos provenientes de frutos de café infectados pelo CoRSV apresentavam menor teor de açúcares redutores e maior condutividade elétrica. Houve também depreciação na qualidade de bebida gerada pelos frutos infectados por meio do teste de degustação (teste de xícara). O peso médio dos grãos provenientes de frutos manchados foi cerca de 5% menor do que dos grãos de frutos sem sintomas. Palavras-chave adicionais: café, qualidade da bebida, perda de produção.well as on the weight of the beans. Infected beans had less reducing sugars and presented an increase in the electrical conductivity. The quality of the beverage prepared from infected fruits was lower than that of healthy fruits. There was a reduction of about 5% in the weight of beans from infected fruits.Additional keywords: Coffee, CoRSV, beverage quality and damage.O Coffee ringspot virus -CoRSV, tentativamente classificado como pertencente à família Rhabdoviridae (5), transmitido pelo ácaro Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) (5), já foi relatado nos estados do Paraná, São Paulo, Minas Gerais e Distrito Federal (3). As partículas de CoRSV são baciliformes (40 nm x 100-110 nm) com estriações transversais de 4 nm (1) e são detectadas em cafeeiro apenas nos tecidos (folhas, ramos e frutos) manchados, ou seja, o vírus não é sistê-mico em plantas de café (5). A doença causada pelo CoRSV caracteriza-se pelas manchas anelares no limbo ou ao longo das nervuras nas folhas, nos frutos e ramos verdes (1). Na década dos 90 houve casos de alta incidência em cafeeiros de Minas Gerais (3).O sabor característico do café se deve à presença e aos teores dos vários constituintes químicos voláteis e não-voláteis. Assim, vários parâmetros têm sido analisados para avaliação da qualidade da bebida como os compostos fenólicos totais, açúca-res totais, redutores e não-redutores, lixiviação de potássio, condutividade elétrica e atividade da polifenoloxidase (2).Devido a escassez de informações sobre os danos causados pelo CoRSV objetivou-se estudar a interferência deste vírus na qualidade de bebida de café e sua i...
Apresenta parte dos resultados da investigação de doutorado intitulada "A Significância do Passado para Professores de História". Os sujeitos são dezessete professores de História de dez colégios de Ensino Médio em Curitiba-PR. Apresenta e categoriza as respostas dos professores sobre o conceito epistemológico de passado em grupos: passado estático, passado para criar empatia, passado como memória, passado para memorização, passado exemplar e passado para orientação. O suporte teórico de análise e investigação desenvolvido por Michael Oake
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