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Base wines for sparkling wine from resistant varieties: effect of the altitude on the aromatic profile
No full textIn a recent context where consumers pay an increasing attention to sustainability in the decision-making process, the use of the resistant varieties in the wine sector have returned at the forefront. Not only but the use of these varieties would reduce production costs due to the lower pesticide utilization to control grapevine moulds. However, the specific aroma profile looked for in base wines is strongly influenced by the cultivar. This work aims to study the volatile composition of base wines produced from five resistant varieties (Bronner, Solaris, Johanniter, Souvignier Gris, Vinera) cultivated in two experimental vineyards located in Trentino (IT): one situated on the valley bottom and the other on the hillside. The results were compared with those of Chardonnay, the main variety used in this area nowadays for sparkling wine production, cultivated in the same plots. The volatiles were extracted from the base wines and the GC-MS/MS analysis allowed to quantify the aromatic compounds belonging to six different chemical classes: acetates, ethyl esters, alcohols, fatty acids, terpenes and norisoprenoids. Among the varieties, Souvignier Gris was characterised by methyl salicylate and 1-hexanol, while Solaris stood out for the concentration of β-damascone, acetates and ethyl esters. Bronner showed significant contents of some grape-derived metabolites, such as β-damascone and linalool. This terpene was also present in higher quantities in Solaris and Johanniter. Regarding the location, acetates and ethyl esters were higher in base wines of the valley bottom and fatty acids, higher alcohols, and terpenes in the hilly plot wines
Scopazzi del melo: correlazione tra malattia e vetustà delle piante
Get PDFIl fitoplasma ‘Candidatus Phytoplasma mali’ è l’agente eziologico degli scopazzi del melo (Apple Proliferation - AP), malattia in grado di comportare ingenti perdite economiche e produttive al settore melicolo. La diffusione avviene tramite insetti vettori, materiale di propagazione infetto e anastomosi radicale. Sebbene non più classificato come organismo da quarantena, permane sul territorio della Provincia Autonoma di Trento l’obbligatorietà dei trattamenti fitosanitari contro i vettori e dell’eradicazione delle piante sintomatiche. Al fine di determinare lo stato di diffusione della malattia e, soprattutto, per pianificare una corretta gestione territoriale della problematica, dal 2001 si svolge in Trentino un monitoraggio statistico nei distretti melicoli della Provincia. L’analisi dei dati raccolti di due casi studio selezionati (Valsugana, Val di Non e Sole) in 10 anni di monitoraggio (2014-2023), vengono presentati. Emerge una correlazione significativa tra la vetustà delle piante di melo e una crescente suscettibilità delle stesse alla malatti
Evolution of volatile compounds after natural vs accelerated aging in classic sparkling wines produced in different climatic areas
Get PDFAfide lanigero e suo parassitoide: biologia e fattori di disturbo
No full textIl monitoraggio ha evidenziato come in Piemonte e Trentino la migrazione inizi verso fine aprile con picco in prossimità di maggio-inizio giugno. Questi dati risultano utili per modulare al meglio le strategie di difesa che devono interferire in maniera ridotta con il protagonista del controllo naturale Aphelinus mal
Foraging behavior of Ganaspis brasiliensis in response to temporal dynamics of volatile release by the fruit–Drosophila suzukii complex
Get PDFThe lineage G1 of Ganaspis brasiliensis is a larval parasitoid of the worldwide pest Drosophila suzukii and one of its most effective natural enemies in the native area. Because of its high degree of host specificity, G. brasiliensis G1 is considered a suitable species for introduction in areas invaded by D. suzukii following a classical biological control approach. Indeed, the release of the parasitoid is currently implemented in the USA and Italy. G1 females attack only host larvae developing in ripening fresh fruits on the plant and not larvae that develop in decaying fruits. To date, virtually no information is available on the cues regulating the foraging behavior of G1. In this study, we therefore aimed to find out whether chemical cues are exploited by G1 females to: (i) locate host fruits; (ii) locate suitable host larvae within infested fruit; (iii) discriminate between infested fresh fruits and infested rotting ones. We used a model system composed of blueberries and D. suzukii tested in two-choice olfactometer bioassays (with D. suzukii-infested fruits, healthy fruits, and pure air as odor targets), followed by the collection and the characterization of volatile organic compounds (VOCs) released by the tested targets. The results showed a clear time-dependent choice made by G1 females of infested versus healthy fruits related to the concomitant development of D. suzukii larvae and fruit degradation. Attraction to infested fruits was recorded during the early stages of infestation, followed by a repellent phase coinciding with fruits largely degraded by larval feeding. We found that the attractiveness of G. brasiliensis G1 towards fruits infested by young larvae was associated with the detection of VOCs released by the infested blueberries, and host’s cuticular hydrocarbons. Conversely, the repellence of older and deteriorated fruits hosting developed D. suzukii larvae was associated with the detection of a fermentation compound produced by microorganisms likely carried inside the fruit by the flies. The response of G1 females to the temporal dynamics of chemical cues emitted by the fruit–host larvae complex was consistent with the high degree of specificity of the parasitoid towards the ripening host fruits and towards D. suzukii
Transcriptomic and volatilomic profiles reveal Neofabraea vagabunda infection-induced changes in susceptible and resistant apples during storage
Get PDFBull’s eye rot is one of the most severe diseases that may affect apple fruit during post-harvest storage. It is caused by the fungus Neofabraea vagabunda, and the mechanism by which the pathogen infects the fruits is only partially understood. In particular, very little is known about the molecular mechanisms regulating the interaction between the pathogen and the host during symptoms development. Despite different apple cultivars show divergent levels of resistance to the pathogen, the genetic basis of these responses is still unknown. In order to better understand the molecular mechanisms occurring in the apple fruit during N. vagabunda infection, a large-scale transcriptome study by RNA-Seq analysis was performed, comparing fruits of the sensitive ‘Roho’ cultivar and the resistant cultivar ‘Ariane’ after artificial infection with N. vagabunda and a storage period of four months. Transcriptomic analyses revealed the regulation of several classes of genes during this period, some of which may be involved in apple-pathogen interaction, such as superoxide dismutases and heat shock proteins (HSPs), ethylene-responsive transcription factors (ERFs), carboxylesterases and NAC transcription factors gene families. Moreover, a volatile analysis was performed, revealing differences in the volatile profile between the resistant and the susceptible cultivar that may help to elucidate the resistance mechanism. RNA-Seq data highlighted several classes of pathogen-related genes, such as genes coding for enzymes involved in cell wall disruption and in reactive oxygen species (ROS) homeostasis, being differentially regulated between resistant and susceptible fruits and between diseased and healthy fruits of the same cultivar, indicating that apples are capable of perceiving and triggering a molecular response to N. vagabunda infection. Some volatiles, as ethanol and methanol, but also furan and formaldehyde, might be potential markers for N. vagabunda infection; others, such as hexenal and methyl acetate, were found to be putatively involved in regulating apple-fungi interactio
Investigating tritrophic interactions using bioenergetic demographic models
Get PDFA central debate in ecology has been the long-running discussion on the role of apex predators in affecting the abundance and dynamics of their prey. In terrestrial systems, research has primarily relied on correlational approaches, due to the challenge of implementing robust experiments with replication and appropriate controls. A consequence of this is that we largely suffer from a lack of mechanistic understanding of the population dynamics of interacting species, which can be surprisingly complex. Mechanistic models offer an opportunity to examine the causes and consequences of some of this complexity. We present a bioenergetic mechanistic model of a tritrophic system where the primary vegetation resource follows a seasonal growth function, and the herbivore and carnivore species are modeled using two integral projection models (IPMs) with body mass as the phenotypic trait. Within each IPM, the demographic functions are structured according to bioenergetic principles, describing how animals acquire and transform resources into body mass, energy reserves, and breeding potential. We parameterize this model to reproduce the population dynamics of grass, elk, and wolves in northern Yellowstone National Park (USA) and investigate the impact of wolf reintroduction on the system. Our model generated predictions that closely matched the observed population sizes of elk and wolf in Yellowstone prior to and following wolf reintroduction. The introduction of wolves into our basal grass-elk bioenergetic model resulted in a population of 99 wolves and a reduction in elk numbers by 61% (from 14,948 to 5823) at equilibrium. In turn, vegetation biomass increased by approximately 25% in the growing season and more than threefold in the nongrowing season. The addition of wolves to the model caused the elk population to switch from being food-limited to being predator-limited and had a stabilizing effect on elk numbers across different years. Wolf predation also led to a shift in the phenotypic composition of the elk population via a small increase in elk average body mass. Our model represents a novel approach to the study of predator-prey interactions, and demonstrates that explicitly considering and linking bioenergetics, population demography and body mass phenotypes can provide novel insights into the mechanisms behind complex ecosystem processes
Geology and elevation shape bacterial assembly in Antarctic endolithic communities
Get PDFIce free areas of continental Antarctica are among the coldest and driest environments on Earth, and yet, they support surprisingly diverse and highly adapted microbial communities. Endolithic growth is one of the key adaptations to such extreme environments and often represents the dominant life-form. Despite growing scientific interest, little is known of the mechanisms that influence the assembly of endolithic microbiomes across these harsh environments. Here, we used metagenomics to examine the diversity and assembly of endolithic bacterial communities across Antarctica within different rock types and over a large elevation range. While granite supported richer and more heterogeneous communities than sandstone, elevation had no apparent effect on taxonomic richness, regardless of rock type. Conversely, elevation was clearly associated with turnover in community composition, with the deterministic process of variable selection driving microbial assembly along the elevation gradient. The turnover associated with elevation was modulated by geology, whereby for a given elevation difference, turnover was consistently larger between communities inhabiting different rock types. Overall, selection imposed by elevation and geology appeared stronger than turnover related to other spatially-structured environmental drivers. Our findings indicate that at the cold-arid limit of life on Earth, geology and elevation are key determinants of endolithic bacterial heterogeneity. This also suggests that warming temperatures may threaten the persistence of such extreme-adapted organism
The FEM grapevine crossbreeding program for resistance to the main ampelopathies
Get PDFThe technique of crossing, free or controlled, has always been a source of variability allowing the selection of new varieties with improved fitness. Therefore, one promising strategy towards a sustainable viticulture is crossbreeding for resistance traits to biotic stresses under climate change condition to reduce pesticide usage and improve resilience. With this awareness and vision, the Edmund Mach Foundation (FEM) began its grapevine genetic improvement program in the 1990s. Later, in 2010 with the exploration of the genetic pool of resistance loci to downy and powdery mildew, a group of accessions was selected as donors. Next, genotypes with stacked (“pyramided”) loci were generated through marker-assisted parental selection (MAPS) with up to seven loci combining resistance to both mildews. Then, upon protocol optimization highly efficient marker-assisted seedling selection (MASS) was established, allowing since 2019 to overcome phenotypic screening and revealing inter- and intra-population effects. Upon multi-year agronomic surveys, grape quality evaluation and wine tastings, in 2018 four new varieties were registered for their novel organoleptic characteristics and tolerance to gray mold. In 2020 four (mid)- resistant varieties to mildews were patented and in 2024 other four are in the process. At the meantime, the resistance to other “emergent” ampelopathies, as black rot, is being introgressed. Various collaborations are in place across the national territory for the exploitation of the superior parental lines. Lately, the genetic and phenotypic characterization of the FEM germplasm (ca. 3,000 accessions) has been completed, so that the scouting process within such biodiversity is continuously ongoing
Remote sensing for the assessment of spatio-temporal variability of grassland cover and phenology
No full textGlobal change is impacting grasslands through multiple processes and is driving severe consequences to their structure and functioning, and to the ecosystem services they provide. The recent advancements in remote sensing imagery availability offer new opportunities to tackle the challenge of grasslands monitoring, providing unprecedented revisiting frequency on wide areas at fine spatial resolution. Unfortunately, there are still few standardized indicators available to track grassland processes, and many processes still lack a thorough understanding. During my Ph.D., I focused on four main goals: i) assessing the grassland fractional vegetation cover prediction capability of newly available remote sensing products; ii) developing a easy to use, free, and cloud-based tool for grassland management intensity monitoring; iii) developing a workflow for grassland flowering phenology extraction using time-lapse cameras; iv) better understanding how plant phenology is shifting in climatically heterogenous mountain landscapes, and how this is affecting ecosystem productivity. Our findings demonstrated that the raw spectral signature of grasslands does not exhibit a linear variation across the fractional vegetation cover gradient, and that Sentinel-2 and PlanetScope have a higher fractional vegetation cover prediction capability compared to previously available imagery, especially in areas under patchy degradation and restoration processes. We introduced a model for estimating grassland mowing frequency, which can effectively be used under different management and environmental conditions. It was validated on small and fragmented parcels compared to previous studies, and it can be run using a provided ready to use code working on a cloud platform. We presented a new workflow for grassland flowering phenology extraction of single (or group of) species from time-lapse cameras. The workflow opened new possibilities for phenological studies, overcoming laborious and time-consuming ground-based vegetation observations. In the fourth study, we revealed substantial differences in the phenological response among vegetation types and across elevations in the European mountains over the last two decades. In grasslands, spring phenology was advanced at high altitudes and delayed at low altitudes, thus becoming more uniform along the elevational gradient, while in deciduous forests we observed the opposite trend. Remote sensing data indicated that growing season length has not been the primary factor limiting productivity over the last two decades. Therefore, it is crucial to incorporate the decoupling between phenology and productivity when simulating the potential carbon uptake of terrestrial ecosystems in future climate change scenarios. Overall, these four studies showed that remote sensing images and processing workflows can greatly contribute to a better understanding of human- and climate-induced processes impacting grassland and forest ecosystems