Nemátode-dos-citrinos: prevenir o declínio lento do pomar

Os citrinos são as fruteiras mais importantes em termos de produção a nível mundial, com cerca de 130 milhões de toneladas produzidas (World Citrus Organisation, 2020), repartin- do-se por mais de 125 países localizados entre os 40° de latitude a norte e a sul do Equador. Entre as várias ameaças à produção citrícola contam-se os nemátodes fitoparasitas. Os nemátodes fitoparasitas são pequenos animais, de aspeto vermiforme, cilíndricos e alongados, geralmente com menos de 1-2 mm de comprimento, que causam doenças às plantas. A maior parte habita no solo, infe- tando as raízes de onde se alimentam atra- vés do estilete (estrutura na cavidade oral que funciona como uma agulha hipodérmi- ca, sugando o conteúdo das células vegetais). Uns permanecem no exterior (ectoparasi- tas), enquanto outros penetram nas raízes (endoparasitas) e outros ainda avançam nos tecidos do hospedeiro, mas só com a parte posterior (cabeça e pescoço), permanecendo o restante corpo fora da raiz (semiendopara- sitas). O nemátode-dos-citrinos, Tylenchulus semipenetrans, é um semiendoparasita e daí a sua designação específica. De todos os ne- mátodes que podem afetar estas fruteiras, é aquele que tem maior impacte económico, sendo a única espécie presente em todas as regiões produtoras de citrinos do mundo

Bioactivity of Monoterpene Alcohols as an Indicator of Biopesticidal Essential Oils against the Root Knot Nematode Meloidogyne ethiopica

The application of pesticides remains one of the most efficient control methods for phytophagous parasites in crops. Essential oils (EOs) are complex mixtures of highly active compounds that can be used as biopesticides against plant parasitic nematodes. In the present work, the antinematodal activity of the monoterpene alcohols geraniol, linalool, menthol or  -terpineol, which are generally found in high amounts in EOs of some aromatic and medicinal plants, was analyzed on the root knot nematode Meloidogyne ethiopica. Geraniol showed intense and lasting antinematodal activity, suggesting that EOs rich in this compound can be used in the development of nematicidal biopesticides to integrate sustainable pest management strategies against this pest

Parasitismo no nemátode da madeira do pinheiro – Estudo dos mecanismos de regulação de genes para o controlo da doença.

A Fileira do Pinho representou, em 2020, 80% dos postos de trabalho e 45% do volume de negócios nas indústrias florestais, assim como mais de 3% das exportações nacionais de bens. Há, no entanto, um défice de 2,3Mm3 de madeira de pinho que é justificado pelo fogo e a presença do nemátode da madeira do pinheiro (NMP), Bursaphelenchus xylophilus (Centro PINUS, 2021) (Figura 1). A doença da murchidão do pinheiro, causada pelo NMP, é considerada uma ameaça para as florestas de pinheiros em todo o mundo e a sua rápida disseminação nos países aonde foi detetada tem causado um grande impacte ao nível da sustentabilidade dos sistemas agroflorestais e de perda de biodiversidade. Uma vez que a mortalidade do pinheiro-bravo causada pelo NMP e a rápida propagação da doença podem ser exponenciadas pela combinação de condições climáticas, como a seca e as temperaturas mais elevadas, prevê-se que a frequência e propagação da doença será cada vez maior, nos pinhais aonde já existe, e ameace aqueles ainda não afetados existentes na região mediterrânica

PineEnemy - Exploring the NEmatode-MYcobiota interactions in Pine Wilt Disease

Pine wilt disease (PWD) is one of the most important threats to conifer forests in Europe [1] and worldwide [2], causing severe economic and environmental damages. This complex disease results from the interaction between three biological elements: the pathogenic agent Bursaphelenchus xylophilus, also known as pinewood nematode (PWN); the insect-vector (cerambycid beetles of the genus Monochamus) [3], and the host tree, mostly from Pinus spp. [4]. In 1999, B. xylophilus was firstly identified in maritime pines (Pinus pinaster) in Portugal and in Europe [1, 5]. Despite a nationwide monitoring system, enforcement of strict phytosanitary measures and constraints implemented after PWN detection, this devastating problem has spread quickly in Portuguese mainland, Madeira Island [5] and Northern Spain [6]. As a migratory endoparasite, once inside susceptible tree, PWN has the ability to feed on the living parenchyma of the epithelial cells in the resin canals, causing a reduction in water flux and ultimately cessation of resin flow. In the later stages of the disease, PWN assumes a mycetophagous phase. The development of the PWN population appears to be strongly associated with fungi that colonize the declining trees [3]. Fungi harboured in weakened pines are seen as essential for the ongoing development and completion of the PWN life-cycle, affecting not only PWN reproduction [8] but also the number of individuals carried by the insect-vector [9-10]. Through a spatio-temporal analysis, PineEnemy will focus on the characterization of the structure and dynamics of the nematode-fungi interactions through culturable and non-culturable approaches with special emphasis in metagenomics analysis. Our aim is to understand if PWN-associated mycobiota plays a key-role in the development of PWD, in interaction with PWN and insect-vector, and into which extend can be targeted to disrupt the disease cycle

Insights into the role of fungi in Pine Wilt Disease

Pine wilt disease (PWD) is a complex disease that severely affects the biodiversity and economy of Eurasian coniferous forests. Three factors are described as the main elements of the disease: the pinewood nematode (PWN) Bursaphelenchus xylophilus, the insect‐vector Monochamus spp., and the host tree, mainly Pinus spp. Nonetheless, other microbial interactors have also been considered. The study of mycoflora in PWD dates back the late seventies. Culturomic studies have revealed diverse fungal communities associated with all PWD key players, composed frequently of saprophytic fungi (i.e., Aspergillus, Fusarium, Trichoderma) but also of necrotrophic pathogens associated with bark beetles, such as ophiostomatoid or blue‐stain fungi. In particular, the ophiostomatoid fungi often recovered from wilted pine trees or insect pupal chambers/tunnels, are considered crucial for nematode multiplication and distribution in the host tree. Naturally occurring mycoflora, reported as possible biocontrol agents of the nematode, are also discussed in this review. This review discloses the contrasting effects of fungal communities in PWD and highlights promising fungal species as sources of PWD biocontrol in the framework of sustainable pest management actions

First report of Pratylenchus penetrans (Nematoda: Pratylenchidae) associated with amaryllis (Hippeastrum x hybrid), in Portugal

The world flower business is a highly dynamic industry and in Portugal yields around EUR 500 million a year (INE 2013). Root lesion nematodes (RLNs), Pratylenchus spp., are considered the third most important group of plant parasitic nematodes (PPNs) worldwide due to their large distribution, wide host range, and impact on economically important crops (Castillo and Vovlas 2007). The most recent report of RLNs parasitizing amaryllis (Hippeastrum spp.) was the amaryllis lesion nematode, Pratylenchus hippeastri, in Florida (U.S.A.) (Gozel et al. 2007). In 2016, soil and root samples of amaryllis hybrid Hippeastrum × hybridum cv. Benfica were collected from potted plants produced in greenhouses in Montijo (Setúbal Peninsula, Central Portugal), 50 km from Lisbon. Nematodes were extracted from soil samples according to the protocol PM 7/119 (1) (EPPO 2013) and identified to genus level based on morphometrical traits of 10 females and 11 males. DNA extraction was conducted from 10 nematodes separately, followed by PCR amplification and sequencing of the D2/D3 expansion segment of the 28S rRNA and 18S rRNA genes using the primers D2A and D3B (Nadler et al. 1999) and 1813F and 2646R (Holterman et al. 2006). The nucleotide sequences were deposited as MN756841 and MN756509 at the NCBI. RLNs were detected in all five samples in a concentration of around 100 nematodes/100 cm3 of soil. Some primary roots of affected plants showed small, elliptical, reddish-brown lesions and poor growth. More severely affected plants presented stunted, chlorotic foliage and had the cortical lesions enlarged to the point that rotting was severe and many roots were easily detached from the bulb; in some cases, there was not emergence from bulbs. The female body was moderately slender, almost straight when killed by gentle heat, lateral field with four straight lines, body annules distinct, lip with three annules, stylet knobs round, median bulb round, spermatheca round and filled with sperm, tail tapering to rounded terminus, sometimes with two striae. Body length was 558.99 ± 48.50 μm, body width 22.45 ± 2.02 μm, stylet length 18.52 ± 1.02 μm, and tail length 32.91 ± 7.50 μm. Values of a, c, and c′ ratios were 25.95 ± 2.53, 17.62 ± 3.45, and 38.49 ± 4.42; V (%) value was 80.92 ± 1.69. Males were smaller than females with body length 511.37 ± 29.90 μm, stylet length 17.55 ± 1.04 μm, and spicule length 18.53 ± 1.17 μm. No other PPN was found in the suspensions extracted from the soil samples. BLAST hits showed that partial sequence of D2/D3 rRNA loci (540 bp) was 96.2% identical (e-value 0.0) to Pratylenchus penetrans isolate MU2 (KP161612) and voucher T143 (KY828357). The partial sequence of 18S rRNA (650 bp) was 100% identical to P. penetrans isolate ILVO-Pp (MH983023) and 99.81% to P. penetrans Praty-A (AB661627). In the corresponding phylogenetic trees, both P. penetrans sequences clustered together with other species from the penetrans group (P. fallax, P. convallariae, and P. oleae) with good support (Janssen et al. 2017). Nevertheless, although all species within this group share many morphological characteristics (Subbotin et al. 2008), our specimens presented higher similarity, both morphological and molecular, with P. penetrans. So far, this RLN has been found associated mainly with potato fields in Portugal (Abrantes et al. 1987; Esteves et al. 2015); thus, to our knowledge, this is the first report of P. penetrans parasitizing amaryllis, in Portugal

Fungos associados a Platypus cylindrus (Coleoptera: platypodidae) e sua relação com o declinio do montado

Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de AgronomiaThe ambrosia beetle Platypus cylindrus establishes symbiotic relationships with fungi. P. cylindrus may act as a vector for the dispersal of phytopathogenic fungi in the Mediterranean cork oak stands. The aim of this study was to identify the fungi associated with P. cylindrus in Portugal and to understand the role and potential impacts on cork oak stands of both insect and fungi. A complex of fungi was found in association with the insect, namely species of cosmopolitan genera whose exact role in the interaction still remains under discussion. Biscogniauxia mediterranea, the causal agent of charcoal canker disease was also found associated with P. cylindrus which contributes to disease spread in cork oak stands. A total of fourteen representative isolates belonging to Ophiostomatales where selected. Fungal strains were morphologically and molecularly characterized. Three rDNA contiguous regions SSU, ITS and LSU, were profiled for each strain and contrasted with pre-existent Ophiostomatales species worldwide. In addition, pathogenicity tests were conducted. A new Ophiostoma species, with Hyalorhinocladiella anamorph, and a Raffaelea species closely related to R. canadensis were noticed for the first time and in association with the ambrosia beetle. Molecular evidence suggests that a different phylogenetic lineage of Ophiostomatales exists in Portugal. R. montetyi was found to be the primary ambrosia fungus of P. cylindrus. The pathogenicity of R. montetyi towards cork oak seedlings was confirmed and its role as a cork oak declining agent determine

Características clínicas dos pés de idosos portadores de diabetes mellitus tipo II

Introdução: o diabetes mellitus é um problema de saúde pública que vem se destacandono Brasil, tanto pelo aumento da incidência quanto pelos fatores de risco encontrados parao desenvolvimento de suas complicações, dentre as quais estão os relacionados com oscuidados com os pés e hábitos de vida. Objetivo: avaliar as características clínicas dos pésde idosos diabéticos tipo II, cadastrados no CERES de Chapecó (SC). Materiais e métodos: estudo quantitativo descritivo, cuja amostra é de 193 indivíduos de ambos os sexos, idadeentre 60 a 91 anos. Realizou-se investigação acerca do perfil dos entrevistados e seusconhecimentos sobre cuidados com os pés. Avaliamos as características clínicas dos pése sensibilidade com estesiometria. Resultados: quanto ao perfil: 90% dos entrevistadospossuíam baixa escolaridade, 88% eram aposentados e 79% possuíam renda de até umsalário. O estado civil predominante foi de casados (51%). Já em relação aos hábitos: 53%usam tabaco, 72,5% declaram-se sedentários e 88% apresentaram doenças associadas.O exame diário dos pés é realizado diariamente por 86,5%, dos indivíduos avaliados, 11%usam calçados inadequados e somente 18,6% cortam as unhas incorretamente. Somente 1indivíduo apresentou ulceração. A sensibilidade mostrou-se alterada em 99,5% dos casos.Conclusão: percebeu-se que o conhecimento acerca dos cuidados com os pés é sabidopor grande parte dos indivíduos. A manipulação correta dos pés demonstrou ser a granderesponsável pelo baixo índice de ulceração encontrada no estudo. Porém, foram observadosaltos índices de alterações clínicas.