Effects of GA3 pregerminative Treatment on Gentiana luteaL. var. aurantiaca germination and seedlings morphology

[EN] Gentiana lutea L. is widely used in bitter beverages and in medicine; Gentianae Radix is the pharmaceutical name of the root of G. lutea. These uses have generated a high demand. The wild populations of Gentiana lutea var. aurantiaca (M. La´ınz) M. Laínz have been decimated; it is necessary to establish guidelines for its cultivation. Gentian as most alpine species has dormant seeds. Dormancy can be removed by cold and by means of a gibberellic acid (GA3) treatment. However, cold treatments produce low germination percentages and GA3 treatments may produce off-type seedlings. So, the objective was to determine, for the first time, the presowing treatments that allow high germination rate and good seedling morphology. The best pregerminative doses of GA3 to break seed dormancy were 100, 500, and 1000 ppm, while the best doses to optimize the seedling habit were 50 and 100 ppm. This study provides, for the first time, a 100 ppm GA3 dose that led to a high germination rate and good seedling morphology, as the starting point for gentian regular cultivation.SITheauthors acknowledge the RegionalMinistry of Education of the Junta de Castilla y León and the European Social Fund PIRTU Grants (Orden EDU/1867/2009), the Regional Ministry of the Environment of the Junta de Castilla y León Project no. 2008/00134/001, the staff from the Forest and Range Management Research Institute (CRA Agricultural Research Council-Trento), and Asociación Promotora de la Genciana y otras plantas de interés de la montaña occidental leonesa for collaborating to collect gentian material

Regulatory non-coding RNAs in crops health and disease

For many years it was thought that the function of RNA was limited to the process of producing proteins. In recent years, scientific discoveries have been proving the multiple roles of different RNAs in different regulatory mechanisms. These RNA’s are collectively called non-coding RNA’s (ncRNA’s). This review presents the latest advances on the different classes of non-coding RNA’s (ncRNA’s) from their function to mechanisms of action. Special emphasis is given to the long non-coding RNAs as new regulatory elements in eukaryote gene expression and in the processes of epigenetic regulation in plants. We believe that increasing studies of regulatory non-coding RNAs in plants will provide a better understanding of the different types of genes related to crop resistanceThe authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO UID/AGR/00690/2019info:eu-repo/semantics/publishedVersio

Use of VOC Chambers to evaluate the impact of microbial volatile compounds on dry grain insect pests

[EN] Although increasing focus is being given to the control of insect pests with natural products, the study of volatile mediated microbe-insect interactions has been largely neglected so far. Currently, no standardized method is available for the in vitro evaluation of the effects produced on insects by Volatile Organic Compounds (VOCs) directly emitted by actively growing microbial strains. This manuscript presents a reliable protocol using VOC Chambers (Álvarez-García et al., 2021) to assess these effects and specifically those exerted on dry grain insect pests. The methodology also serves to evaluate the impact of these volatile interactions on the grain damage produced by the insects. It allows to vary the level of gas exchange with the environment, thus providing different experimental conditions to emulate diverse natural ones in which these interactions may occur. Our method adapts the use of VOC Chambers for the evaluation of microbe-insect volatile interactions and the in vitro screening of microbial strains that produce potentially bioactive VOCs against insects. It allows assessing the effects of these volatile interactions on the damage produced by insect pests on stored dry grains. Sealed and unsealed setups can be used to determine the impact of ventilation and gas exchange on these interactions.SIWe acknowledge the Junta de Castilla y León, Consejería de Educación for funding this work throughout the project “Application of Trichoderma strains in sustainable quality bean production”; (LE251P18) and the Fundación General de la Universidad de León y la Empresa (FGULEM) and the European Social Fund via a Proof of Concept (ULE-PoC) included in the Plan TCUE. The “Consejería de Educación de Castilla y León”and the European Social Fund also financed the PhD of Samuel Álvarez García (ORDEN EDU/529/2017, June 26 th )

Lifecycle of Dryocosmus kuriphilus Yasumatsu and diversity and importance of the native parasitoid community recruited in the Northern Region of Portugal

In this work, the objective was to learn the life cycle of D. kuriphilus and the diversity of native parasitoids in the northern region of Portugal between 2017 and 2019. The places studied belonged to the regions of Entre-Douro-e-Minho, Beira Interior, and Tr & aacute;s-os-Montes. To achieve the proposed objectives, buds were collected for egg and larva observation, galls were collected for larva, pupa, and adult observation and monitoring, and emergency boxes were used to identify the fauna present in the galls. In this study, 92% of D. kuriphilus adults emerged between June and July, with emergences occurring until September. We also obtained adults in winter, so it is important to study, in future works, the hypothesis of this pest performing diapause. Regarding the study of native parasitoids, compared to other countries, the same families emerged, with good rates of natural parasitism, although with fluctuations over the years. In the three municipalities under study, 11 species were identified (Eupelmus azureus Ratzeburg, Eupelmus urozonus Dalman, Eurytoma brunniventris Ratzeburg, Megastigmus dorsalis (Fabricius), Ormyrus pomaceus (Geoffroy), Sycophila iracemae Nieves Aldrey, Sycophila variegata (Curtis), Sycophila biguttata (Swederus), Torymus flavipes (Walker), Torymus auratus (Mueller), and Torymus notatus (Walker)). The average parasitism rates varied between 1.92% and 10.68%.info:eu-repo/semantics/publishedVersio

Adapting almond production to climate change through deficit irrigation and foliar kaolin application in a mediterranean climate

Irrigation is the best strategy to reduce the adverse effects of water stress on almond trees [Prunus dulcis (Mill) D.A. Web] and improve their productivity. However, in the current context of climatic change, in which the amount of water available for irrigation is increasingly limited, deficit irrigation (DI) strategies have become essential in the almond orchards of southern Europe. Other practices, such as the foliar application of reflective compounds, are being implemented. A three-year experiment (2019–2021) was set in a factorial design in which the effect of regulated deficit irrigation and foliar kaolin spray was evaluated on physiological (predawn leaf water potential, relative water content, leaf area, leaf gas exchange, and chlorophyll fluorescence) and agronomic parameters (yield, yield components, and water use efficiency (WUE)). The treatments include full irrigation (FI), which received 100% of ETc (crop evapotranspiration) during all irrigation seasons; regulated deficit irrigation (RDI), which received 100% of ETc until the kernel-filling stage, reducing the application to 35% ETc during the kernel-filling stage until harvest; and both irrigation regimes combined with kaolin application and two cultivars, Constantí and Vairo. More negative water potential values were observed in the RDI treatments compared to the FI treatments. There were no significant differences in the stomatal conductance, photosynthetic rate, or transpiration rate between treatments with RDI and FI, demonstrating the almond tree’s good adaptation to irrigation reduction in the kernel-filling stage. The two cultivars had different responses in cumulative yield throughout the three years of the trial. The cv. Constantí did not present significant differences between the FI and RDI treatments, translating into improved WUE. In contrast, the cv. Vairo suffered a reduction in accumulated performance in the RDI treatments with respect to the FI. The foliar application of kaolin did not present differences in yield and very few in the physiological activity of the almond trees. With the results obtained, we can suggest that under the conditions of our experiment, the combination of RDI and the kaolin foliar application can help save irrigation water and produce almonds more sustainably.The authors acknowledge the financial support of Operational Group EGIS—Estratégias de Gestão Integrada do Solo e da Água em Espécies Produtoras de Frutos Secos, PDR2020-1.0.1- FEADER-030981, funded by PT2020 and EAFRD (European Agricultural Fund for Rural Development). David Barreales thanks the Foundation for Science and Technology (FCT) for the Ph.D. grants SFRH/BD/139393/2018 and COVID/BD/152770/2023. This manuscript is part of David Barreales’s Ph.D. thesis. The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES(PIDDAC) and CIMO (UIDB/00690/2020 and UIDP/00690/2020), and to the Associate Laboratory SusTEC (LA/P/0007/2021).info:eu-repo/semantics/publishedVersio

Within-field distribution of the damson-hop aphid Phorodon humuli (Schrank) (Hemiptera: Aphididae) and natural enemies on hops in Spain

A field trial was performed in a hop yard throughout 2002, 2003 and 2004 in order to determine the within-field distribution of Phorodon humuli (Schrank) (Hemiptera: Aphididae) and its natural enemies. The distribution of P. humuli was directly affected by the position of the hop plants in the garden, with significantly higher concentrations of aphids (p=0.0122 in 2002 and p=0.0006 in 2003) observed along the edge. However, in 2004 the plants located on the marginal plots had similar populations to those on the more inner plots. This can be explained by a higher wind speed which made it more difficult to land on edge plants first. The hop aphid’s main natural enemy was Coccinella septempunctata (Coleoptera: Coccinellidae), whose population was greatest where the aphids were most abundant with a significantly greater number of eggs (p=0.0230) and adults (p=0.0245) in 2003. Lacewing eggs were also frequently observed, with a significantly higher population (p=0.0221 in 2003 and p=0.0046 in 2004) where the aphid numbers were high. The number of winged aphids was greatest towards the margins of the garden in 2003. It is argued that the spatial distribution of the hop aphid and its natural enemies could be used to plan a sampling program and to estimate the population densities of these insects for use in integrated pest management programs

Effect of Sustainable Preharvest and Postharvest Techniques on Quality and Storability of High-Acidity ‘Reinette du Canada’ Apple

[EN] Consumers are more disposed towards paying price premiums for sustainable food products. This fact is especially important for products with a PDO (Protected Designation of Origin) label, such as the high-acidity apple cultivar ‘Reinette du Canada’. However, ‘Reinette du Canada’ apple fruit is affected by two of the main post-harvest disorders in apple cultivars, bitter pit and senescent breakdown. As a means to achieve sustainable production of this high-quality apple cultivar, the effect of a sustainable preharvest technique, summer pruning, in combination with a zero-residue postharvest treatment allowed in organic farming on calcium-related disorders and quality in global terms in this PDO-labelled apple cultivar was assessed during storage. The combination of the two sustainable practices was an effective tool in diminishing senescent breakdown from 43% to 17% and to decrease bitter pit incidence by up to 21% (from 36% to 15%) throughout storage, especially in fruit with high susceptibility to this disorder during storage. Moreover, the overall acceptability was kept high (values of more than 3 on a 5-point scale) when applying this environment-friendly sustainable horticulture practice, which will not only reduce the synthetic pesticide input in the apple agroecosystem, but also contribute to producing fruit with zero residuesSIWe gratefully acknowledge Aquilino Guerra Mallo for technical support and for the professional cultivation of the experimental fruit trees. The authors would like to thank the three anonymous reviewers who helped improve the manuscript with their comments and suggestion

Self-Inhibitory Activity of Trichoderma Soluble Metabolites and Their Antifungal Effects on Fusarium oxysporum

[EN] Self-inhibitory processes are a common feature shared by di erent organisms. One of the main mechanisms involved in these interactions regarding microorganisms is the release of toxic di usible substances into the environment. These metabolites can exert both antimicrobial e ects against other organisms as well as self-inhibitory ones. The in vitro evaluation of these e ects against other organisms has been widely used to identify potential biocontrol agents against phytopathogenic microorganisms. In the present study, we performed membrane assays to compare the self-inhibitory e ects of soluble metabolites produced by several Trichoderma isolates and their antifungal activity against a phytopathogenic strain of Fusarium oxysporum. The results demonstrated that Trichoderma spp. present a high self-inhibitory activity in vitro, being a ected in both their growth rate and the macroscopic structure of their colonies. These e ects were highly similar to those exerted against F. oxysporum in the same conditions, showing no significant di erences in most cases. Consequently, membrane assays may not be very informative by themselves to assess putative biocontrol capabilities. Therefore, di erent methods, or a combination of antifungal and self-inhibitory experiments, could be a better approach to evaluate the potential biocontrol activity of microbial strains in order to pre-select them for further in vivo trials.SIThis research was funded by Junta de Castilla y León, Consejería de Educación for the project “Application of Trichoderma strains in sustainable quality bean production”; (LE251P18) and for the grant to Samuel Álvarez García of the Junta de Castilla y León according to ORDER EDU/529/2017, of June 26, co-financed by the European Social Fund. The research has been funded also by the University of León: Universidad de León; Convocatoria de ayudas para el fomento de la publicación en acceso abierto a profesores de nueva incorporación; programa 463A.3.01

Volatile-mediated interactions between Trichoderma harzianum and Acanthoscelides obtectus: A novel in vitro methodology to evaluate the impact of microbial volatile compounds on dry grain storage pests

.Biological interactions mediated by Biogenic Volatile Organic Compounds (BVOCs) is a well-established field that has been researched for decades. Although extensive focus is currently given to the control of insect pests using natural molecules, the study of volatile interactions between microorganisms and insects has been largely neglected and has only begun to attract more attention in recent years. In this work, we developed a novel protocol to assess the effects of microbial BVOCs directly produced by growing microbial strains on dry grain insect pests and the seed damage they cause, using VOC Chambers to evaluate both sealed and unsealed conditions. Four Trichoderma harzianum strains were tested against Acanthoscelides obtectus, a wild type and three of its transformants. These had been previously obtained by introducing the tri5 gene and thus overproducing the volatile trichodiene, or by silencing the erg1 gene, which encodes for a squalene epoxidase, therefore reducing ergosterol levels and increasing squalene ones in the fungus. Results demonstrated that ventilation plays a key role in these interactions. All fungal strains significantly increased adult mortality in sealed conditions, while this effect was barely noticeable in unsealed ones. Nevertheless, subsequent insect emergence from bean seeds and bean damage were still significantly reduced in both conditions. The erg1 silenced strains caused significantly higher levels of adult mortality than the rest in sealed conditions and lower insect emergence in both sealed and unsealed ones. Bean damage produced by insects was lower also when exposed to BVOCs from these strains in sealed conditions. Conversely, trichodiene overproduction did not show enhanced toxicity or significant reduction of insect emergence and bean damage in the tested conditions. Therefore, T. harzianum BVOCs, especially those from erg1 silenced strains, should be further researched for their potential use in the biological control of A. obtectus infestation in dry grain storing facilities. VOC Chambers have shown themselves to be a reliable method in the screening of in vitro volatile mediated interactions between growing microbial strains and insect pests.S

Germination and Agronomic Traits of Phaseolus vulgaris L. Beans Sprayed with Trichoderma Strains and Attacked by Acanthoscelides obtectus

[EN] Acanthoscelides obtectus, one of the world’s most important post-harvest pests, attacks wild and cultivated common beans (Phaseolus vulgaris L.). Four Trichoderma strains, Trichoderma arundinaceum IBT 40,837 (=Ta37), a wild-type strain producer of trichothecene harzianum A (HA); two transformed strains of Ta37, Ta37-17.139 (∆tri17) and Ta37-23.74 (∆tri23); and T. brevicompactum IBT 40,841 (=Tb41), a wild-type strain producer of the trichothecene trichodermin, were evaluated to determine the effect of these compounds on the virulence of A. obtectus and the effect of these strains on the seed’s capacity of germination and on the agronomic traits of the plants grown from these seeds. Treatments of bean seeds with different Trichoderma strains provided varying survival rates in A. obtectus adults, so life survival of insects after Tb41 strain application was reduced to 15 days. ∆tri17 and Tb41 strains sprayed on P. vulgaris beans resulted in low weight losses (1.21 and 1.55%, respectively). In spite of the low germination percentage of beans treated with ∆tri23 strain (lower than the germination percentages of the rest of the fungal strains applied), this treatment encouraged a greater Wet Weight of Aerial Part of the plants grown from both damaged and undamaged beans. High germination rates of Ta37 and ∆tri17 strains (higher than with the rest of treatments), did not turn into a greater Wet Weight Aerial Part and Wet Weight of Root System in the future plants developed. Linear regression between the number of exit holes and the wet weight aerial part on the one hand, and between the number of exit holes and the wet weight root system on the other, showed interaction, so ∆tri23 and Tb41 strains behaved differently in comparison to their respective control treatments. The number of exit holes of beans treated with ∆tri23 or Tb41 was negatively correlated with both the wet weight aerial part and the wet weight root system in P. vulgaris plants. ∆tri23 sprayed on undamaged beans caused the greatest Wet Weight Aerial Part and wet weight root system in plants. Due to the good results obtained by ∆tri23 and Tb41 strains in this work, more studies for A. obtectus control, P. vulgaris plant growth and trichothecenes production by these strains should be explored, in order to advance in the knowledge of how these fungi could be used in the field crop, together with the application of management strategies to mitigate risks for farmers and to minimize environmental contamination