Over the past 10 years, Tomato yellow vein streak virus (ToYVSV) has been a major begomovirus in the main solanaceous crop region of Campinas, São Paulo, which includes counties of Sumaré, Monte Mor, Elias Fausto, and Indaiatuba. The top leaves of potato plants (Solanum tuberosum) having deforming mosaic symptoms (dms), which includes a yellow mosaic or mottling on distorted and deformed leaflets, were associated with this geminivirus (4). Recently, a table potato crop (cv. Agata) from Sumaré, with a record of a few or no white flies (Bemisia tabaci), during the winter season of June to September 2006 had 5 to 7% dms, suggestive of seed potato tuber borne virus infection. Double-antibody sandwich (DAS)-ELISA for Potato virus Y (PVY), Potato leaf roll virus (PLRV), Potato virus X (PVX), and Potato virus S (PVS) (SASA kits and protocols, Edinburgh, Scotland) gave negative results for four field collected potato plants showing dms. Bioassays (mechanical transmission from potato leaf extracts in phosphate buffered saline, 1:5 w/v) with test plants of Nicotiana tabaccum cvs. Turkish and TNN, Gomphrena globosa, Chenopodium quinoa, Datura metel, Solanum tuberosum, and a Physalis sp. were all negative. Inoculated D. stramonium developed symptoms resembling ToYVSV infection including vein clearing and mild mottling on new leaves 2 to 3 weeks postinoculation. Using primers PAC1v1978/PAV1c715 for begomovirus detection (3), the predicted PCR amplified fragment of 1,320 bp was obtained from leaf DNA extracted from all four of the dms field potato plants, as well as the inoculated and symptomatic D. stramoniium test plants. Sequence analysis indicated 100% nt identity among the 1.3-kb PCR fragments obtained from potato and D. stramonium infected plants. Sequences of 96 cloned amplicons (pGEM-T Easy Kit; Promega, Madison, WI) from symptomatic plants in the Sumaré potato field were 98 to 99% identical to Tomato severe rugose virus (ToSRV). BLAST analysis of a consensus sequence (Sequencher 3.1; Gene Codes Corporation, Ann Arbor, MI) revealed more than 95 and 99% identity with ToSRV isolates from Uberlandia (Accession No. AY029750) and Goias (Accession No. DQ207749), respectively. The DNA-based phylogenetic dendrogram confirmed the highest similarity with ToSRV and the lowest similarity with ToYVSV (72%), which was located in another cluster. These results indicate that ToSRV was the causal agent producing dms in potato plants from Sumaré. Therefore, similarly to ToYVSV (4), potato dms can be caused by ToSRV. Preliminary tests revealed that ToSRV was transmitted via seed tubers. Thus, it is of concern for seed potato certification in Brazil, especially in the major seed-potato-producing state of Santa Catarina where an outbreak of ToSRV was recently reported in tomato crops (1). Although ToSRV has been identified in other solanaceous crops in Brazil, especially tomato (Lycopersicon esculentum) and sweet pepper (Capsicum annum) (2), to our knowledge, this is the first report of ToSRV in potato in Brazil. Reference: (1) A. T. M. Lima et al. Fitopatol. Bras. 31:224, 2006. (2) D. N. Nozaki et al. Summa Phytopathol. 33:93, 2007. (3) M. R. Rojas et al. Plant Dis. 77:340, 1993. (4) J. A. C. Souza-Dias et al. CultivarHF 5(26):22, 2004.
Influência dos diferentes tipos de estacas caulinares no enraizamento e morfoanatomia de Aphelandra nitida Ness & Mart. (Acanthaceae) Influence from different types of stem cuttings on rooting and morphology of Aphelandra nitida Ness & Mart. (Acanthaceae)
O uso de plantas medicinais é tão antigo quanto às civilizações. Contudo, as regionalidades e sinonímias muitas vezes levam ao uso errôneo dessas plantas. Dessa forma, o objetivo do trabalho foi descrever a anatomia e micromorfologia da epiderme foliar de Emilia sonchifolia (L.) DC. ex Wight. (Asteraceae) a fim de contribuir com a correta identificação da espécie. O material vegetal foi coletado na Universidade Federal do Espírito Santo, sendo coletadas cinco folhas completamente expandidas de cinco indivíduos. Para as análises micromorfológicas o material foi fixado em FAA 50 e desidratado em série etílico. As análises e digitalização das imagens foram realizadas ao microscópio eletrônico de varredura. Para as análises anatômicas, o material foi fixado em FAA 50 e, posteriormente, transferido para álcool 50%. Foram realizadas seções paradérmicas das superfícies foliares, as quais foram coradas com azul de alcião e safranina. Em ambas as superfícies foram evidenciadas células epidérmicas com paredes celulares sinuosas, estômatos anomocíticos e anisocíticos, além de grandes tricomas tectores pluricelulares. As análises no MEV mostraram deposição de cera epicuticular em ambas as superfícies. Conclui-se que os longos tricomas tectores pluricelulares e os estômatos anomocíticos e anisocíticos são um conjunto de caracteres que permitem a identificação de E. sonchifolia.
RESUMO Tillandsia usneoides, conhecida como barba-de-velho, possui importância na medicina popular, com atividade antiviral, antioxidante, hipoglicêmica e antitumoral. Nesse contexto, o objetivo do trabalho foi realizar a caracterização anatômica foliar de T. usneoides, atrelado a testes histoquímicos visando auxiliar na identificação da espécie e subsidiar estudos taxonômicos e farmacológicos. O material vegetal foi coletado em uma área de restinga no norte do Espírito Santo. Para as análises anatômicas foram utilizadas técnicas usuais de anatomia vegetal. Para os testes histoquímicos, foram analisadas as seguintes substâncias: amido, lignina, lipídeos, compostos fenólicos e cristais. Em vista transversal, o limbo apresenta epiderme uniestratificada recoberta por cutícula e presença das células centrais das escamas epidérmicas. Subsequente, a hipoderme é caracterizada por células aclorofiladas, dispostas em uma única camada. O mesofilo é homogêneo, constituído por parênquima clorofiliano, cujas células possuem formato isodiamétrico. As fibras preenchem as extremidades dos feixes vasculares, os quais encontram-se dispersos na região central do mesofilo. Em vista frontal, as células da epiderme possuem parede celular ondulada, estômatos tetracíticos, geralmente recobertos pelas escamas, que são numerosas e distribuídas de forma aleatória ao longo da folha. Dentre os testes histoquímicos analisados, houve apenas reação positiva para lipídeos e os cristais do tipo ráfides possuem composição de oxalato de cálcio. Os caracteres distintivos de T. usneoides são folhas com formato circular, parede celular ondulada das células epidérmicas, estômatos tetracíticos e escamas com séries de quatro, oito e dezesseis células, sendo a ala assimétrica. PALAVRAS-CHAVE: Anatomia da folha, Testes Histoquímicos, Tillandsioideae. LEAF ANATOMY AND HISTOCHEMISTRY OF Tillandsia usneoides (L.) L.
Quesnelia quesneliana is an endemic species from Brazil with restricted distribution in restinga areas and has been suffering from changes in its habitat. This study aimed to evaluate the influence of light on the morpho-anatomy and pigment content of Q. quesneliana. The samples were collected in the Liberdade neighborhood in São Mateus, Espírito Santo State, Brazil, which is impacted by anthropization. The influence of light was tested comparing individuals completely exposed to it and individuals under shade. For a morphobiometric analysis, 150 individuals were measured for each light condition, and for pigment determination, 10 leaves were used for each light condition. For anatomical analysis, samples were fixed in 50% FAA and transferred to 70 % ethanol solution after 48 hours. Cross sections were made on roots and stems, and transverse and paradermal sections on leaves. It was concluded that individuals exposed to light are smaller, with higher carotenoid content, while shaded individuals are larger, with more succulent and darker leaves due to greater accumulation of chlorophyll. Anatomically, the individual’s structure is similar.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.