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Effects of deficit irrigation practices on the Soil-Plant-Atmosphere system: a case study on Vitis vinifera L. (Teroldego cv.) from Trentino Alto Adige, Italy
Full text linkViticulture in Trentino Alto Adige (northern Italy) mainly focuses on wine quality rather than quantity, and it is well known that wine quality can be improved by applying moderate water stress during fruit ripening. But with climate change extreme drought periods are becoming more and more frequent, and longer often coupled with high air temperatures. This is challenging for farmers, since prolonged periods of water scarcity negatively affect the physiological activity of the vines, the yield and the increase of water demand from irrigation reservoirs. On the other hand, summer extreme precipitations cause, as well, crop loss, plant diseases, nutrient leaching and soil erosion. With appropriate precision irrigation practices the timing and the amount of water can be controlled to guarantee the optimal amount of water to the crops and ensure the best quality of the products, also avoiding water loss by runoff or deep percolation resulting from an excess of irrigation. In this perspective it is essential to accurately monitor the water status of the SPAC, which is the Soil-Plant-Atmosphere Continuum. This study focuses on the comparison of two different irrigation regimes on a vineyard located in Mezzolombardo (Trentino Alto Adige, Italy), with the analysis of the water status of the field during the 2024 growing season and the comparison of the musts after harvest. Four vines (Vitis vinifera L., Teroldego cv.) on the same vine row were chosen: two of them were kept without irrigation, and the others were treated as usual with irrigation scheduled by the irrigation consortia. The water state of the plant was monitored with microtensiometers (FloraPulse Co., Davis, USA) embedded in the trunk and measuring the stem water potential (Ψstem) allowing a continuous, non-invasive and remote monitoring of Ψstem. The amount of water in the soil was measured with tensiometers, located near each plant, and atmospheric parameters were given by a meteorological station nearby. The start of the 2024 growing season has been extremely wet and limited the initial development of the vegetation, but August was characterized by almost no water income and particularly high temperatures. Despite the lack of water, the non irrigated plants never reached Ψstem values associated to water stress, whereas the irrigated plants were kept regularly irrigated even when the water in the soil was above field capacity, leading to a potential loss of water by deep percolation. The comparison of the musts between the two thesis highlighted no significant differences in the organoleptic properties and the Ravaz Index showed that the non irrigated vines were in a better vegetative-productive equilibrium with respect to the irrigated plants. In order to adapt the agricultural production to the water imbalance given by the changing climate, it is more effective to provide irrigation only when needed, and not to rely on a scheduled calendar. It is confirmed that precision irrigation practices accurately support the crop needs and it should be one common practice to be developed and enhanced in the near future
“Flavescence dorée” phytoplasma strains genetic variability: a comparative genomics approach
No full text“Flavescence dorée” (FD) is a severe and epidemic grapevine yellows disease associated with the “flavescence dorée” phytoplasma transmitted by the leafhopper Scaphoideus titanus, affecting most of the major European viticultural regions. Control of FD relies only on insecticides against S. titanus and uprooting of the infected plants. No fully resistant grapevine cultivar is available thus, understanding phytoplasmas pathogenicity and genomics is crucial for developing alternative defense strategies. This research describes the genome sequencing of four “flavescence dorée” strains, detected in different symptomatic grapevine varieties collected in the Trentino province (north Italy), using Oxford nanopore long-read sequencing. A comparative analysis of all available phytoplasmas genomes with these four “flavescence dorée” phytoplasmas was performed, providing insights into the genomics of these “flavescence dorée” strain
Trophic interactions are key to understanding the effects of global change on the distribution and functional role of the brown bear
Full text linkBiotic interactions are expected to influence species' responses to global changes, but they are rarely considered across broad spatial extents. Abiotic factors are thought to operate at larger spatial scales, while biotic factors, such as species interactions, are considered more important at local scales within communities, in part because of the knowledge gap on species interactions at large spatial scales (i.e., the Eltonian shortfall). We assessed, at a continental scale, (i) the importance of biotic interactions, through food webs, on species distributions, and (ii) how biotic interactions under scenarios of climate and land-use change may affect the distribution of the brown bear (Ursus arctos). We built a highly detailed, spatially dynamic, and empirically sampled food web based on the energy contribution of 276 brown bear food species from different taxa (plants, vertebrates, and invertebrates) and their ensemble habitat models at high resolution across Europe. Then, combining energy contribution and predicted habitat of food species, we modelled energy contribution across space and included these layers within Bayesian-based models of the brown bear distribution in Europe. The inclusion of biotic interactions considerably improved our understanding of brown bear distribution at large (continental) scales compared with Bayesian models including only abiotic factors (climate and land use). Predicted future range shifts, which included changes in the distribution of food species, varied greatly when considering various scenarios of change in biotic factors, providing a warning that future indirect climate and land-use change are likely to have strong but highly uncertain impacts on species biogeography. Our study confirmed that advancing our understanding of ecological networks of species interactions will improve future projections of biodiversity change, especially for modelling species distributions and their functional role under climate and land-use change scenarios, which is key for effective conservation of biodiversity and ecosystem service
Vibrazioni alimentari di Liriomyza trifolii sulle piante di pomodoro e comportamento di ricerca dell'ospite di Diglyphus isaea
Full text linkThe sustainable fungicide choline pelargonate inhibits Botrytis cinerea and Phytophthora infestans growth by altering membrane structure and lipid content
Full text linkBotrytis cinerea and Phytophthora infestans are two of the most widespread phytopathogens worldwide and are mainly controlled by the frequent application of synthetic chemical fungicides. Sustainable alternatives are required to reduce the possible negative effects on human health and the environment. This study aimed to characterize the mechanism of action of the sustainable fungicide choline pelargonate (CP) against B. cinerea and P. infestans in vitro. CP inhibited mycelial growth and spore germination of B. cinerea and P. infestans, causing the leakage of electrolytes and nucleic acids with dose-dependent effects. Ultrastructural alterations of the plasma membrane and cytoplasm were found in B. cinerea and P. infestans cells, with negative impacts on membrane functionality. Moreover, CP altered the content of free fatty acid, phosphatidic acid, phosphatidylcholine, phosphatidylethanolamine, and triglyceride lipid classes in B. cinerea and P. infestans mycelia, as a possible perturbation of lipid metabolism and stimulation of lipid hydrolysis. Pelargonic acid was partially incorporated into triglyceride lipids, suggesting attempted detoxification mechanisms in both phytopathogens. In conclusion, CP is a choline carboxylate with promising inhibitory activity against phytopathogen
Integrative study of European species of Forficula Linnaeus, 1758: cryptic species and complex phylogenetic patterns (Dermaptera)
Full text linkImpatto dello stadio di sviluppo e della densità larvale di Drosophila suzukii sul comportamento di ricerca del parassitoide specialista Ganaspis kimorum
Full text linkDrosophila suzukii è un dittero invasivo originario del Sud-Est asiatico, divenuto un serio problema per numerose colture da frutto, in particolare ciliegio, fragola e piccoli frutti, in tutte le aree di nuova colonizzazione a livello mondiale. L’elevata capacità riproduttiva di D. suzukii e la sua ampia polifagia, comprendente anche specie spontanee, riducono drasticamente l’efficacia del controllo chimico. Tutto ciò, associato all’assenza di efficienti nemici naturali autoctoni nelle aree di nuova invasione, ha stimolato la ricerca di agenti di controllo biologico specifici nell’area di origine di D. suzukii. Tra le specie di parassitoidi larvali individuate, Ganaspis kimorum (= G. brasiliensis G1) (Hymenoptera: Figitidae) è risultato altamente specifico per D. suzukii. Un ceppo di G. kimorum, originario del Giappone, è stato rilasciato in campo, in Italia a partire dal 2021, seguendo un approccio di controllo biologico classico. Ganaspis kimorum parassitizza le larve giovani di D. suzukii esclusivamente all’interno di frutti maturi sulla pianta ospite. Nell’ambito delle attività previste dal progetto PRIN 2022 “SUSHI”, è stato quindi avviato uno studio sulla bioetologia del parassitoide al fine di caratterizzare i fattori regolanti il comportamento di ricerca dell’ospite. Allo scopo, è stato utilizzato un sistema modello comprendente frutti di mirtillo, D. suzukii e G. kimorum. Il comportamento di ricerca dell’ospite da parte del parassitoide è stato analizzato mediante biosaggi in olfattometro a due vie. Le femmine fecondate sono state testate su tre combinazioni: frutti infestati vs aria pura, frutti sani vs aria pura e frutti infestati vs frutti sani, considerando come variabili il numero di giorni dall’ovideposizione del fitofago e la densità larvale dell’ospite. I risultati evidenziano che, con elevata infestazione (circa 10 larve/frutto), G. kimorum sceglie in modo significativo i frutti infestati nei primi tre giorni dall’ovideposizione di D. suzukii (frutti infestati da larve giovani). Dal quarto giorno, i frutti infestati esercitano repellenza, probabilmente a causa del decadimento del frutto e della presenza di larve mature. Con infestazione più bassa, di 1 o 5 larve/frutto, la discriminazione del parassitoide si evidenzia solo dopo tre giorni. I composti organici volatili coinvolti nei segnali di attrazione e repellenza sono stati identificati con GC-MS. Questo studio amplia le conoscenze sulla specificità di G. kimorum verso le larve di D. suzukii ed evidenzia una sua elevata capacità di ricerca. Le femmine del parassitoide si sono dimostrate in grado di individuare le larve ospiti anche a basse densità e nello stadio di sviluppo (larve di 1-2 giorni di età) più idoneo alla parassitizzazione, sfruttando semiochimici volatili rilevabili a lunghe distanze
Unveiling Diversity in amino acid stable isotope profiles for classifying rice Varieties, refining types and cultivation systems
Full text linkIsotope Ratio Mass Spectrometry (IRMS) is a promising tool in organic authentication cases. Premium-priced Italian rice varieties (Carnaroli, Arborio, Baldo) are used in cuisines worldwide for their unique qualitative properties. Organic authentication of rice by morphological assessment is unfeasible, while its market availability at different refining stages (brown, white) further increases the data variability. In this study, bulk and compound-specific (CS) − IRMS analysis of nine rice amino acids (AAs), by elemental analyser (EA) – IRMS and gas chromatography (GC) − combustion (C) − IRMS, respectively, were applied in order to explore their organic authentication potential in cases involving different rice varieties and refining types. The individual and interactive effects of the different variables were assessed on the δ13CAAs, δ15NAAs, δ13Cbulk and δ15Nbulk, and the sample classification was attempted by linear discriminant analysis (LDA) and decision tree analysis (DTA). Organic authentication of brown rice was achieved by CS-IRMS. Generic rice was differentiated from all Italian organic and conventional varieties (δ15Nleucine < 2.5 ‰). The δ13C values of glutamic acid, glycine, phenylalanine and proline, significantly contributed to the complete LDA separation of conventional Arborio, conventional Carnaroli and organic Carnaroli samples. This study showcases the interplay between refining type, variety and cultivation, which should be considered in cases of organic authentication by IRMS method
Fungal biodiversity of apple bark, leaves, stems, and fruit under rain shelters with reduced fungicide schedule
Full text linkThe use of rain shelters is a promising agronomic practice to protect crops from rainfall, reducing the need for fungicides to control certain pathogens that take advantage of leaf wetness. However, the combined condition of absence of rain and reduced fungicide schedule can affect the fungal populations, possibly favoring biocontrol agents and/or other pathogens. In this study, the effects this practice on epiphytic and endophytic fungal communities associated with barks, leaves, flowers, and fruits of two apple cultivars (Fuji and Golden Delicious) were evaluated across two seasons. Apple plants were grown under two conditions in a commercial-like orchard: (1) covered by rain shelters with reduced fungicide schedule and (2) uncovered with standard integrated pest management (IPM) schedule. The use of rain shelters combined with reduced fungicide applications affects the overall fungal community structure and their abundance of specific taxa. Leaf epiphytes were the most impacted community, and fungal communities also differed between the two apple cultivars. The use of rain shelters helped reduce fungicide input in the orchard, but it increased the abundance of potential pathogens compared to the IPM in open field conditions, such as powdery mildew and apple scab. Understanding how the plant microbiome responds to new practices that help in reducing fungicides can help developing strategies that avoid the build-up of potentially new pathogens