RESUMO

As condições fitossanitárias de plantas arbóreas podem ser utilizadas para caracterizar comunidades vegetais, indicando condições de qualidade estrutural do componente vegetal. Assim, ambientes alterados antropicamente podem representar uma ameaça à fitossanidade. O objetivo deste estudo foi averiguar as características fitossanitárias do componente arbóreo em um trecho de 400 metros de extensão ao longo da linha férrea localizada no município de Três Barras, estado de Santa Catarina, Brasil. Foram registradas 33 espécies arbóreas, 29 gêneros e 19 famílias. Os índices ecológicos avaliados foram a abundância, densidade, riqueza e equabilidade. Foram avaliados 190 indivíduos em relação a qualidade da copa, grau de infestação de cipós e sanidade da árvore. Embora a qualidade da copa e a sanidade sejam majoritariamente boas, houve um relativo alto número de infestação de cipós. Tal ocorrência pode ser devido à condição de borda em que as plantas se encontram. Os bons índices ecológicos aliados ao baixo número de espécies arbóreas exóticas também indicam boas condições ecológicas e de fitossanidade local. Contudo, são necessários mais estudos (p. ex. florísticos e fitossociológicos) na área. A arborização urbana das proximidades aliada à formação de corredores ecológicos que liguem os fragmentos à Floresta Nacional de Três Barras pode ser uma medida de conservação e regeneração a ser explorada.

Phytosanitary conditions of tree plants can be used to characterize plant communities, indicating structural quality conditions of the plant component. Thus, anthropically altered environments may pose a threat to plant health. The objective of this study was to investigate the phytosanitary and ecological condition of the tree component in a stretch of 400 meters along the railway line located in the municipality of Três Barras, Santa Catarina state, Brazil. Thirty-three tree species were recorded, in addition to 54 taxonomically unidentified individuals. The ecological indices evaluated were abundance, density, richness and evenness. 190 individuals were evaluated in terms of crown quality, Abstract degree of liana infestation and tree health. Although canopy quality and health are mostly good, there was a relatively high number of vine infestations. Such an occurrence may be due to the edge condition in which the plants are located. The good ecological indices combined with the low number of exotic tree species also indicate good ecological conditions and local plant health. However, more studies are needed in the area. Urban afforestation, combined with the formation of ecological corridors that connect the fragments to the Três Barras National Forest, can be a conservation and regeneration measure to be explored.

RESUMO

The European Commission requested the EFSA Panel on Plant Health to evaluate the probability of entry of pests (likelihood of pest freedom at entry), including both, regulated and non-regulated pests, associated with unrooted cuttings of the genera Petunia and Calibrachoa produced under physical isolation in Guatemala. The relevance of any pest for this opinion was based on evidence following defined criteria, based on the methodology used for high-risk plants adapted for the specificity of this assessment. Nineteen EU regulated pests (Bemisia tabaci, pepper golden mosaic virus, pepper huasteco yellow vein virus, tomato severe leaf curl virus, tomato yellow leaf curl virus, tomato spotted wilt virus, Liriomyza huidobrensis, Liriomyza sativae, Liriomyza trifolii, Bactericera cockerelli, Eotetranichus lewisi, Epitrix subcrinita, Epitrix cucumeris, Helicoverpa zea, Chloridea virescens, Spodoptera ornithogalli, Ralstonia solanacearum, Ralstonia pseudosolanacearum, Xanthomonas vesicatoria) and one EU non-regulated (Phenacoccus solenopsis) pest fulfilled all relevant criteria and were selected for further evaluation. For these pests, the risk mitigation measures proposed in the technical dossier from Guatemala were evaluated taking into account the possible limiting factors, and an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The limited and partially conflicting information provided in the dossier contributes to the wide estimates of pest freedom. The estimated degree of pest freedom varies among the pests evaluated, with Ralstonia spp. (R. solanacearum and R. pseudosolanacearum) being the pest most frequently expected on the imported cuttings. The expert knowledge elicitation indicated, with 95% certainty, that between 9916 and 10,000 bags containing unrooted cuttings per 10,000 would be free of Ralstonia spp.

RESUMO

Plant pathogens and pests can cause significant losses in crop yields, affecting food security and the global economy. Many traditional chemical pesticides are used to combat these organisms. This can lead to the development of pesticide-resistant strains of pathogens/insects and negatively impact the environment. The development of new bioprotectants, which are less harmful to the environment and less likely to lead to pesticide-resistance, appears as a sustainable strategy to increase plant immunity. Natural Rhamnolipids (RL-Nat) are a class of biosurfactants with bioprotectant properties that are produced by an opportunistic human pathogen bacterium. RL-Nat can act as plant resistance inducers against a wide variety of pathogens. Recently, a series of bioinspired synthetic mono-RLs produced by green chemistry were also reported as phytoprotectants. Here, we explored their capacity to generate novel colloidal systems that might be used to encapsulate bioactive hydrophobic compounds to enhance their performance as plant bioprotectants. The synthetic mono-RLs showed good surfactant properties and emulsification power providing stable nanoemulsions capable of acting as bio-carriers with good wettability. Synthetic RLs-stabilized nanoemulsions were more effective than RLs suspensions at inducing plant immunity, without causing deleterious effects. These nanoemulsions were innocuous to native substrate microbiota and beneficial soil-borne microbes, making them promising safe bio-carriers for crop protection.

RESUMO

Effectors are small, secreted molecules that alter host cell structure and function, thereby facilitating infection or triggering a defense response. Effectoromics studies have focused on effectors in plant-pathogen interactions, where their contributions to virulence are determined in the plant host, i.e., whether the effector induces resistance or susceptibility to plant disease. Effector molecules from plant pathogenic microorganisms such as fungi, oomycetes and bacteria are major disease determinants. Interestingly, the effectors of non-pathogenic plant organisms such as endophytes display similar functions but have different outcomes for plant health. Endophyte effectors commonly aid in the establishment of mutualistic interactions with the plant and contribute to plant health through the induction of systemic resistance against pathogens, while pathogenic effectors mainly debilitate the plant's immune response, resulting in the establishment of disease. Effectors of plant pathogens as well as plant endophytes are tools to be considered in effectoromics for the development of novel strategies for disease management. This review aims to present effectors in their roles as promotors of health or disease for the plant host.

RESUMO

Most beetle-fungus symbioses do not represent a threat to agricultural and natural ecosystems; however, a few beetles are able to inoculate healthy hosts with disease-causing fungal symbionts. Here, we report the putative nutritional symbionts associated with five native species of ambrosia beetles colonizing commercial avocado trees in four locations in Michoacán. Knowing which beetles are present in the commercial orchards and the surrounding areas, as well as their fungal associates, is imperative for developing a realistic risk assessment and an effective monitoring system that allows for timely management actions. Phylogenetic analysis revealed five potentially new, previously undescribed species of Raffaelea, and three known species (R. arxi, R. brunnea, R. fusca). The genus Raffaelea was recovered from all the beetle species and across the different locations. Raffaelea lauricola (RL), which causes a deadly vascular fungal disease known as laurel wilt (LW) in Lauraceae species, including avocado, was not recovered. This study points to the imminent danger of native ambrosia beetles spreading RL if the pathogen is introduced to Mexico's avocado orchards or natural areas given that these beetles are associated with Raffaelea species and that lateral transfer of RL among ambrosia beetles in Florida suggests that the likelihood of this phenomenon increases when partners are phylogenetically close. Therefore, this study provides important information about the potential vectors of RL in Mexico and other avocado producing regions. Confirming beetle-fungal identities in these areas is especially important given the serious threat laurel wilt disease represents to the avocado industry in Mexico.

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This study investigated the profile of orchidists, their cultivation practices, and their knowledge about pests in orchid cultivation in the state of Bahia. There were applied 74 questionnaires to producers (amateurs and commercials) in 23 municipalities. The data were submitted to univariate statistics using the chi-square test, the Mann­Whitney U-test and the Kruskal­Wallis H-test. The survey shows that orchid cultivation is mostly practiced by women (67.6%) and those with higher education (48.7%). Most respondents were amateurs (87.8%). Insects (39.9%) and diseases (32.5%) were the main organisms associated with phytosanitary problems. The presence of insects was reported to occur mainly in the leaves (47%), mainly mealybugs (46.3%). Correspondence was significant between commercial and amateur groups according to the pairwise Mann­Whitney U-test(1) = 370.04 and p < 0.01. The Kruskal­Wallis H-test(27) = 924.78 and p < 0.01 discriminated categories between the groups. Despite the growing interest in orchid cultivation in the state of Bahia, most orchidists are amateurs. The study warns about the risk of pest dispersion between crops since exchanging plants and purchasing specimens in open markets are common practices.

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RESUMEN Los métodos clásicos de mejoramiento han estrechado la base genética del arroz. La selección recurrente (SR) permite el mejoramiento de una población, mediante la pirámidación de alelos favorables de diversos donantes y de origen genético diverso. Ha sido usada en Colombia por CIAT/CIRAD, para el desarrollo y el mejoramiento del acervo genético del arroz Oryza sativa L., tipo Japonica Tropical de secano en sabanas ácidas. Se evaluaron en bloques completos al azar, con tres repeticiones, 50 líneas avanzadas junto con el testigo comercial Corpoica Llanura 11. Se observó diferencia significativa entre líneas de arroz para las variables dependientes rendimiento de grano, días a floración, vigor e incidencia de Pyricularia en hojas y cuello, así como manchado de grano. Las líneas 39 y 37, de la población PCT-11, presentaron los mayores rendimientos, con 6,471 y 6,192kg ha-1, respectivamente, diferentes significativamente del testigo y de nueve líneas de ciclo tardío de la población PCT-4, que presentaron rendimientos muy bajos. Especialmente, la línea 39, mostró menor incidencia del hongo Pyricularia en hojas, que el testigo comercial Corpoica Llanura 11. Los presentes resultados muestran la utilidad de la SR en arroz de sabanas, para generar líneas superiores en rendimiento, en resistencia a enfermedades, en adaptación a las sabanas ácidas y el potencial para contribuir a la diversificación de su base genética.

ABSTRACT The classical breeding methods have narrowed the genetic base of rice. The pedigree method with a limited number of elite and genetically related parents, can reduce variability in long term studies. The development of populations with a broad genetic base and the use of breeding methods that allow the continuous accumulation of favorable alleles could overcome these disadvantages. Recurrent selection (SR) allows the improvement of a population through the pyramidation of favorable alleles of diverse donors and of diverse genetic origin. It has been used in Colombia by CIAT/CIRAD for the development and improvement of the genetic stock of Oryza sativa L. rice, a tropical rain-fed Japonica type in acid savannas. They were evaluated in complete blocks at random with three repetitions, 50 advanced lines of this project, together with the commercial control Corpoica Llanura 11. There was a significant difference between rice lines for the dependent variables grain yield, days to flowering, vigor and incidence of Pyricularia in leaves and spotted of grain. Lines 39 and 37 of the PCT-11 population presented the highest yields, with 6.471 and 6.192kg ha-1, respectively, significantly different from the control and nine late cycle lines of the PCT-4 population, which presented very low yields. Especially line 39 showed a lower incidence of the Pyricularia fungus on leaves than the commercial control Corpoica Llanura 11. The present results and others obtained in Colombia and Brazil, show the utility of SR in savanna rice to generate superior lines in yield, resistance to diseases, adaptation to acid savannas and the potential to contribute to the diversification of the genetic base.

RESUMO

- Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most destructive diseases affecting banana crops worldwide. Therefore, the development of resistant cultivars is a promising alternative to mitigate the effects of the disease on banana plantations. The objectives of this study were to induce somaclonal variation in banana cultivars of the Silk and Cavendish types and to select somaclones resistant to subtropical race 4, thereby enabling the production of fruit in areas where this race is present. Shoot clump apexes of the Grand Naine and Maçã (Silk) cultivars were grown in MS medium. The cultures were subcultured four times. They were then challenged with fusaric acid (FA) in an experiment consisting of four treatments with different concentrations (0.1, 0.2, 0.3, and 0.4 mM) and five repetitions, each consisting of a Petri dish containing seven multiple shoot clumps in MS culture medium supplemented with 2.5 mg/L benzylamine purine. Multiple shoot clumps without the addition of FA were also used in the experiment, and were subcultured three times and maintained in a dark room. The multiple shoot clumps that survived the treatment with FA were transferred to MS medium and maintained in the growth chamber in the presence of light. The regenerated plants were later planted in tanks containing soil infested with an isolate classified as Foc subtropical race 4 (Foc STR4), and were evaluated for resistance to the pathogen at 90 days after inoculation (d.a.i.). Pathogen structures were confirmed by root clarification and root staining technique. All somaclones of the Maçã (Silk) cultivar were susceptible to Fusarium wilt and two somaclones of the Grand Naine cultivar were selected as resistant. The addition of FA as a selective agent was effective in the selection of somaclones among plants of the Grand Naine cultivar, as shown by the selection of two somaclones resistant to Foc STR4. The next step will consist of the agronomic and market potential validation of the selected somaclones, aiming to confirm their potential use by producers.

RESUMO

In Guadeloupe, a French overseas territory located in the Eastern Caribbean, infectious and non-infectious diseases, loss of biodiversity, natural disasters and global change threaten the health and well-being of animals, plants, and people. Implementing the "One Health" (OH) approach is crucial to reduce the archipelago's vulnerability to these health threats. However, OH remains underdeveloped in Guadeloupe, hampering efficient and effective intersectoral and transdisciplinary collaborations for disease surveillance and control. A multidisciplinary research group of volunteer researchers working in Guadeloupe, with collective expertise in infectious diseases, undertook a study to identify key attributes for OH operationalization by reviewing past and current local collaborative health initiatives and analyzing how much they mobilized the OH framework. The research group developed and applied an operational OH framework to assess critically collaborative initiatives addressing local health issues. Based on a literature review, a set of 13 opinion-based key criteria was defined. The criteria and associated scoring were measured through semi-directed interviews guided by a questionnaire to critically evaluate four initiatives in animal, human, plant, and environmental health research and epidemiological surveillance. Gaps, levers, and prospects were identified that will help health communities in Guadeloupe envision how to implement the OH approach to better address local health challenges. The methodology is simple, generic, and pragmatic and relies on existing resources. It can be transposed and adapted to other contexts to improve effectiveness and efficiency of OH initiatives, based on lessons-learned of local past or current multi-interdisciplinary and intersectoral initiatives.

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The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects. This Scientific Opinion covers plant health risks posed by tubers of Ullucus tuberosus imported from Peru, taking into account the available scientific information, including the technical information provided by Peru. The relevance of an EU quarantine pest for this opinion was based on evidence that: (i) the pest is present in Peru, (ii) U. tuberosus is a host of the pest and (iii) the pest can be associated with the commodity. The relevance of any other pest, not regulated in the EU, was based on evidence that: (i) the pest is present in Peru (ii) the pest is absent in the EU; (iii) U. tuberosus is a host of the pest; (iv) the pest can be associated with the commodity and (v) the pest may have an impact and can pose a potential risk for the EU territory. There are five pests i.e. one insect (Amathynetoides nitidiventris), two nematodes (Atalodera andina and Nacobbus aberrans) and two viruses (the Andean potato latent virus (APLV) and the potato virus T (PVT)) that fulfilled all relevant criteria were selected for further evaluation. For the five pests, the risk mitigation measures proposed in the technical dossier from Peru were evaluated taking into account the possible limiting factors. For each of the five pests, an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. The degree of pest freedom varies among the pests evaluated, with PVT being the pest most frequently expected on the imported commodities. The Expert Knowledge Elicitation indicated, with 95% certainty, that between 9,157 and 10,000 tubers out of 10,000 would be free of PVT.