Context dependency, co-introductions, novel mutualisms, and host shifts shaped the ectomycorrhizal fungal communities of the alien tree Eucalyptus globulus

The identity and relevance of the ectomycorrhizal (ECM) fungal partners of Eucalyptus globulus was investigated in NW Spain, to detect which symbionts mainly support its invasiveness. Root tips of E. globulus and of three common native plant species (Quercus robur, Pinus pinaster and Halimium lasianthum) were collected in eucalypt plantations, Q. robur forests, P. pinaster plantations and shrublands. Fungal taxonomical identity was ascertained by use of rDNA and direct sequencing. We studied diversity, composition and colonization rate of the ECM fungal communities of E. globulus to determine if fungal assemblages are host specific (i.e. similar in different habitats) or more dependent on the neighbourhood context. We also identified the type of associations formed (i.e. co-introductions, familiar or novel associations). Twenty-six ECM taxa were associated with E. globulus. Most of them engaged in novel associations with eucalypts, whereas only three fungal species were co-introduced Australian aliens. Eucalypt fungal richness, diversity and colonization rate differed between habitats, being higher in native oak forests, whereas in shrublands E. globulus showed the lowest colonization rate and diversity. The Australian fungus Descolea maculata dominated the eucalypt fungal assemblage and also spread to the native host plants, in all the habitats, posing the risk of further co-invasion.Xunta de Galicia | Ref. EM2014/03

Soil microbiota impact on Boletus edulis mycelium in chestnut orchards of different ages

Biotic factors (host plant age and soil microbiota) influencing Boletus edulis mycelium frequency and concentration have been investigated. The study was carried out in September, October and November 2018 and 2020, using six orchards of chestnut hybrid Castanea × coudercii of 40-, 10- and 3-years-old. Taxonomical identity of bacterial and fungal species was ascertained by DNA metabarcoding. Mycelium frequency and concentration of B. edulis were studied through quantitative PCR (qPCR) of soil samples. It was hypothesized that mature plants (40-years-old) have a greater soil microbiota associated at the rhizosphere, in comparison with young plants (10- and 3-years-old). This situation may reverberate on B. edulis mycelium that should be more abundant in 40-years-old orchards, also thanks to the higher number of beneficial interactions whit soil microbiota. It was found that host plant age significantly altered bacterial and fungal assemblages in both years. Bacterial fraction was dominated by the phylum Proteobacteria, Acidobacteria and Actinobacteria and showed a higher species richness and diversity in orchards of 10- and 3-years-old. Fungal phylum such as Basidiomycota was more abundant in 40- and 10-years-old orchards, whereas Ascomycota and Mortierellomycota were more abundant in the 10- and 3-years-old orchards. Mycelium frequency of B. edulis in soil samples was higher in 2020 (97 %) than in 2018 (19 %), although without differences between plant age and sampling month in each year. Boletus edulis mycelium concentration was higher in 2020 than in 2018, and in September 2020, whereas plant age did not have any effect. Of 173 bacterial taxa considered, the 12 %, 54 % and 82 % of the significant correlations with B. edulis mycelium concentration were found in 40-, 10- and 3-years-old orchards, respectively. On the other hand, of 180 fungal taxa, the 12 %, 24 % and 42 % of the significant correlations occurred in 40-, 10- and 3-years-old orchards, respectively. This investigation represents the first report about the role of soil microbiota on the ecology of B. edulis in Castanea agro-ecosystem.Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-095568-B-I00Xunta de Galicia | Ref. ED431D 2017/18Xunta de Galicia | Ref. ED431E 2018/0

Artificial intelligence unveils key interactions between soil properties and climate factors on Boletus edulis and B. reticulatus mycelium in chestnut orchards of different ages

The main objective of this study was to determine the possible interaction of two important abiotic factors (soil and climate) on the mycelial concentration and frequency of the ectomycorrhizal fungi Boletus edulis and B. reticulatus, using traditional statistics and artificial neural network tools. The frequency and concentration of Boletus mycelium were determined over three months (September, October, and November), and two years (2018 and 2020), in three hybrid chestnuts (Castanea × coudercii) orchards of 40-, 10-, and 3- years-old, using real-time qPCR. Statistical analysis revealed a significant effect of the year on B. edulis mycelium concentration and of the sampling plot (different tree ages) on B. reticulatus frequency. The combination of artificial intelligence networks (ANN) with fuzzy logic, named neurofuzzy logic (NF), allowed the construction of two robust models. In the first, using year, month, and sampling plot as inputs, NF identified hidden interactions between year and month on B. edulis mycelium concentration and between sampling plot and sampling month on B. reticulatus mycelium frequency, thus improving the information obtained from the statistical analysis. In the second model, those three factors were disaggregated into 44 inputs, including 20 soil properties and 24 climatic factors, being NF able to select only 8 as critical factors to explain the variability found in both ectomycorrhizal Boletus species regarding mycelial frequency and concentration. Specifically, NF selected two chemical soil properties (cation exchange capacity and total carbon) and three physical properties (macroaggregates, total porosity, and soil moisture at field capacity), as well as their interactions with three climatic elements (cumulative difference between precipitation and potential evapotranspiration (P-PET-1-2) and water deficit (WD-1-2) in the previous two months and excess water (WE-1) in the month prior to sampling. These results provide a much deeper understanding and new insights into the ecology and the role of abiotic factors which explain the different mycelial development patterns of ectomycorrhizal fungi such as B. edulis and B. reticulatus in chestnut agroecosystems

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

Darwin and the postcopulatory sexual selection

12 páginas, 5 figuras.[EN] The concept of sexual selection was proposed by Darwin to explain the evolution of secondary sexual characters, i.e., those characters not directly related to the reproductive function, and that clearly do not help their bearers to increase their survivorship. Sexual selection occurs by means of male-male competition and female choice. Darwin explicitly excluded genital organs from sexual selection, because sexual differences in those characters were believed to be under natural selection only. Over the second half of the XX century several conceptual revolutions occurred. First, the fights between males were prolonged in the time scale to include the competition between spermatozoa. Second, female choice was widened to include also behaviours and mechanisms taking place after copulation. The time was ready for the development of the idea of “postcopulatory” sexual selection, which was not anticipated in Darwinian texts, perhaps because at that time –end of XIX century- discussing about these concepts was not socially acceptable. The idea of a permanent conflict between males and females was also added to the current paradigm studying sexual selection, as well as the effect of this force on genitalic evolution, which has opened a revolutionary field of study, going further away than Darwin never imagined.[ES] El concepto de selección sexual fue propuesto por Darwin para explicar la evolución de caracteres sexuales secundarios (es decir, no relacionados directamente con la función reproductora), que claramente no contribuyen a incrementar la supervivencia de sus portadores. Esta selección ocurre mediante la lucha entre machos por el apareamiento y la elección por parte de las hembras. De forma explícita, excluyó de esta selección a los órganos genitales, ya que estas diferencias sexuales se creían debidas exclusivamente a la acción de la selección natural. Durante la segunda mitad del siglo XX se produjeron varias revoluciones conceptuales en este campo. En primer lugar, el mecanismo de competencia entre machos se prolongó en el tiempo para incluir la competencia entre los espermatozoides. Seguidamente la elección femenina se amplió para incluir conductas y mecanismos de elección que ocurren después de que la cópula se inicia. Nació así la idea de selección sexual “postcópula”, que no se vislumbra en los escritos darwinianos, quizás porque hablar de estos comportamientos no era algo socialmente aceptable a finales del siglo XIX. Actualmente las investigaciones han incorporado de forma sobresaliente la idea de que la reproducción es un conflicto permanente entre sexos, y el hecho de que la evolución genital es también objeto de selección sexual, ha abierto un campo de estudio revolucionario, yendo más allá de lo que Darwin había imaginado.Peer reviewe

Defoliation negatively affects plant growth and the ectomycorrhizal community of Pinus pinaster in Spain

In this work, by artificially reproducing severe (75%) and moderate (25%) defoliation on maritime pines Pinus pinaster in NW Spain, we investigated, under natural conditions, the consequences of foliage loss on reproduction, abundance, diversity and richness of the fungal symbionts growing belowground and aboveground. The effect of defoliation on tree growth was also assessed. Mature needles were clipped during April 2007 and 2008. Root samples were collected in June-July 2007 and 2008. Collection of sporocarps was performed weekly from April 2007 to April 2009. Taxonomic identity of ectomycorrhizal fungi was assessed by using the internal transcribed spacer (ITS) regions of rDNA through the polymerase chain reaction (PCR) method, subsequent direct sequencing and BLAST search. Ectomycorrhizal colonization was significantly reduced (from 54 to 42%) in 2008 by 75% defoliation, accompanied with a decline in species richness and diversity. On the other hand, sporocarp abundance, richness and diversity were not affected by foliage loss. Some ECM fungal symbionts, which are assumed to have a higher carbon cost according to the morphotypes structure, were reduced due to severe (75%) defoliation. Furthermore, 75% foliage loss consistently depressed tree growth, which in turn affected the ectomycorrhizal growth pattern. Defoliation impact on ECM symbionts largely depends on the percentage of foliage removal and on the number of defoliation bouts. Severe defoliation (75%) in the short term (2 years) changed the composition of the ECM community likely because root biomass would be adjusted to lower levels in parallel with the depletion of the aboveground plant biomass, which probably promoted the competition among mycorrhizal types for host resources. The persistence of fungal biomass in mycorrhizal roots would be crucial for nutrient up-take and recovery from defoliation stress of the host plants. © 2010 Springer-Verlag.European Social Fund and by the MEC-INIA of the Spanish Government (RTA2006-00124-00-00). Consellería de Medio Ambiente, Xunta de Galicia (Montserrat Pestaña Nieto has a predoctoral grant)Peer Reviewe

Toxicity of synthetic and biological insecticides against adults of the Eucalyptus snout-beetle Gonipterus scutellatus Gyllenhal (Coleoptera: Curculionidae)

Toxicity by contact and by ingestion of lufenuron, flufenoxuron, lambda (k)-cyhalothrin, cypermethrin, thiamethoxam and five entomopathogenic insecticides (three formulations of Beauveria bassiana, a compound containing spores of Metarhizium anisopliae var. acridum, and a mixture of Brevibacillus laterosporus, Bacillus licheniformis and Bacillus chitinosporus) were evaluated on adults of the Eucalyptus snout-beetle Gonipterus scutellatus Gyllenhal (Coleoptera: Curculionidae) under laboratory conditions. By contact, entomopathogenic fungus B. bassiana EC and the pyrethroid k-cyhalothrin exhibited the highest efficiency, achieving 100 and 97.5% mortality, respectively. By ingestion, the highest mortality was obtained by B. bassiana EC (100%) and thiamethoxam (95%). Flufenoxuron and lufenuron, bacteria mixture and M. anisopliae showed a weak toxicity. Furthermore, we found a sex-biased mortality, being males more affected. Due to the good performance and low risk to humans and environment, B. bassiana EC (strain PPRI 5339) appears to be the most promising product to promote an IPM programme in South Africa

Depredación larvaria de Xanthandrus comtus (Harris, 1780) (Diptera, Syrphidae) sobre orugas de Mamestra brassicae (Linnaeus, 1758) (Lepidoptera, Noctuidae) en la provincia de Pontevedra (Galicia, España)

We report for the first time the presence of Xanthandrus comtus Harris, 1780 preying on Mamestra brassicae Linnaeus, 1758 young larvae in kale crops in Pontevedra province (Galicia, Spain). It is the second time that this syrphid is detected feeding on macrolepidopteran larvae. This is the first record of this species for Pontevedra province and the third one for Galicia.Se aporta por primera vez la observación de Xanthandrus comtus Harris, 1780 en la provincia de Pontevedra (Galicia, España), alimentándose de orugas de Mamestra brassicae Linnaeus, 1758 en cultivos de berzas. Es la segunda vez que este sírfido es encontrado depredando orugas de un macrolepidóptero. Se trata de la primera cita de esta especie para la provincia de Pontevedra y de la tercera para Galicia.Peer reviewe

Diadegma fenestrale (Hymenoptera, Ichneumonidae): la mejor herramienta para el control biológico de la polilla de la col Plutella xylostella (Lepidoptera, Yponomeutidae)

Se ha evaluado en Galicia, entre junio y noviembre de 2010, la presencia de la polilla de la col Plutella xylostella (Yponomeutidae) y la tasa de parasitismo natural alcanzada por el conjunto de himenópteros parasitoides en cultivos de berza y repollo, libres de tratamientos fitosanitarios. El agente de control biológico más prometedor fue Diadegma fenestrale (Ichneumonidae), que ha alcanzado el 70% de tasa de parasitismo de las larvas de la polilla. Las berzas recibieron un ataque más intenso de P. xylostella, aunque la tasa de parasitismo fue siempre muy satisfactoria tanto en berzas (66%) como en repollos (76%). La abundancia máxima de la polilla se produjo en el mes de julio, aunque gracias a la actividad de los parasitoides, ésta se redujo de manera vistosa en el mes de agosto. El estudio evidencia la importancia del mantenimiento de la comunidad de insectos beneficiosos para los cultivos, ya que de ellos depende la posibilidad de controlar las plagas sin perjuicios para el ambiente.Peer Reviewe

Effects of two chemical insecticides and two bio-insecticides on the Eucalyptus snout-beetle "Gonipterus scutellatus" Gyllenhal and its biological control agent "Anaphes nitens" Girault

[EN] We have combined the results of experiments done in the laboratory and in the field to evaluate the toxicity of four insecticides: flufenoxuron, ethofenprox, azadirachtin and Bacillus thuringiensis subsp. kurstaki on the eucalyptus snout-beetle Gonipterus scutellatus and its natural enemy Anaphes nitens. Adults and larvae of G. scutellatus and adults of A. nitens were exposed to treated leaves of Eucalyptus globulus in the laboratory. The weevil egg-capsules were treated topically applying 1 ul droplets of each insecticide on the surface. B. thuringiensis showed no activity against the different stages of the pest, or the adult parasitoids. Azadirachtin acted as a larvicide by ingestión (72.5% of mortality after 7 days). Ethofenprox showed the highest toxicity in all the experimental groups. It determined 100% of mortality of adults and larvae of G. scutellatus after 24 h and 93.1% of mortality rate of the egg-capsules. On the last day of observation, flufenoxuron provoked 92.5% of adult mortality and 100% of larval mortality. In the laboratory, only ethofenprox and flufenoxuron have adversely affected A. nitens (97.5% mortality after 48 h.). The field experiment was done on three localities, with a preliminary sampling, and three samplings after the applications of the products, on the 7th, 14th and 30th day. In each sampling we evaluated parasitism rate and the abundance of adults, larvae and egg-capsules. Only fluenoxuron and ethofenprox reduced the pest population, but ethofenprox also significantly decreased parasitism rate after seven days. Considering the possible development of an integrated pest management plan, we suggest that flufenoxuron is the most appropriate product to be used in association with the natural enemy.[ES] Se han integrado los resultado de experimentos realizados en el laboratorio y en el monte para averiguar la toxicidad de cuatro insecticidas: flufenoxuron, etofenprox, azadiractina y Bacillus thuringiensis var. kurstaki, sobre adultos, larvas y puestas del defoliador del eucalipto Gonipterus scutellatus y sobre los adultos de su agente de control biológico Anaphes nitens. En el laboratorio se midió el efecto mediante la exposición de los sujetos experimentales a hojas de Eucalyptus globulus previamente tratadas y la aplicación tópica de 1 ul de cada insecticida sobre las puestas. Los resultados indican que B. thuringiensis no ha tenido ningún efecto sobre la plaga ni sobre los parasitoides adultos. Azadiractina ha mostrado un efecto larvicida por ingestión y contacto (72.5% de mortalidad después de 7 días). El resultado más contundente lo ha provocado etofenprox, con el 100% de mortalidad de adultos y larvas de G. scutellatus a las 24 horas y el 93.1% de tasa de mortalidad de las puestas. A los 7 días, flufenoxuron ha producido una tasa de mortalidad de los adultos del 92.5% y del 100% de las larvas. En el laboratorio sólo etofenprox y flufenoxuron han incrementado la tasa de mortalidad de A. nitens (en ambos casos 97.5% a las 48 horas). En el monte se han aplicado los cuatro insecticidas en tres localidades, efectuándose un muestreo preliminar antes del tratamiento y al 7.°, 14." y 30.° día. En cada muestreo se evaluó la tasa de parasitismo de las puestas de G. scutellatus y la abundancia de adultos, larvas y puestas. De los cuatro insecticidas sólo flufenoxuron y etofenprox han conseguido contener la población de la plaga, aunque etofenprox ha sido el único que también ha disminuido de manera significativa la tasa de parasitismo de las puestas a los siete días del tratamiento. En vista del desarrollo de un plan de lucha integrada contra G. scutellatus, flufenoxuron parece ser el producto más apropiado.Este estudio ha sido financiado por Agrodan S.A, Agrichem S.A., BASF, ENCE, y Reboreda S.L.Peer reviewe