Wild fruit tree species are increasingly recognized for their ecological, genetic, and practical value, particularly in the context of biodiversity conservation and reforestation. Among them, European wild pear (Pyrus pyraster (L.) Burgsd.) and almond-leaved pear (P. spinosa Forssk.) offer promising potential, yet their reproductive biology remains insufficiently understood. This study examines how fruit and seed morphology, alongside fruit chemical composition and environmental and geographical variables, influence germination success and early seedling development. Specifically, we aimed to determine whether these traits can reliably differentiate the species and detect intraspecific variation across provenances. In order to explore these distinctions at both interspecific and intrapopulation levels, fruits were sampled from ten natural populations. We assessed their morphological and chemical characteristics, and conducted a two-year nursery trial to examine germination dynamics and seedling performance. Germination was consistently higher in Pyrus spinosa, while P. pyraster produced more vigorous seedlings. Seed mass showed a strong positive correlation with seedling height and collar diameter, but did not predict germination rate. Fruit stalk length also correlated strongly with seed mass and seedling growth, suggesting indirect genetic and physiological linkages. Significant intraspecific variability was detected in both species, mediated by geographic and ecological structuring of the populations. Indeed, full RDA model revealed a strong joint effect of environmental and geographic predictors on studied traits in both species. These findings highlight how both inherited traits and provenance shape early developmental success, offering practical implications for restoration, nursery propagation, and conservation amid shifting environmental conditions.
The effective pollination period (EPP) is a key factor determining fruit set in sweet cherry, as it depends on the overlap between pollen tube growth and ovule longevity. This study investigated the duration and components of the EPP in three autochthonous cultivars (‘Stonska’, ‘Gomilička’, and ‘Tugarka’) grown in the Mediterranean region of Croatia over two consecutive flowering seasons. The EPP was determined under field conditions using sequential hand pollinations, while stigma receptivity, pollen tube growth, and ovule viability were assessed by fluorescence microscopy. Significant genotypic and seasonal variation in EPP and fruit set was observed. ‘Stonska’ and ‘Gomilička’ exhibited extended EPPs (9 and 11 days) and moderate to high fruit set. In contrast, ‘Tugarka’ showed a considerably shorter EPP (4–5 days) and consistently low fruit set (<10%). Stigma receptivity and pollen tube growth were not limiting factors for fertilization. However, rapid ovule degeneration in ‘Tugarka’, particularly under elevated temperatures during flowering, reduced the overlap between pollen tube arrival and ovule viability. These results indicated that ovule longevity plays a major role in determining fruit set and EPP under Mediterranean conditions. The study highlights genotypic differences in temperature sensitivity and provides insight into the potential impact of rising spring temperatures on sweet cherry production.
Increasing variability in water availability, caused by changing climatic conditions, is a major constraint for onion production. The present study investigated the physiological, metabolic and molecular responses of the diploid onion Allium cepa L. and the triploid hybrid Allium × cornutum Clementi ex Visiani under drought and waterlogging. Plants were exposed to controlled stress conditions, and responses were evaluated through relative water content (RWC), electrolyte leakage (EL), photosynthetic pigments, amino acid composition, total phenolic content (TPC), individual phenolic compounds and expression of antioxidant genes (CAT, SOD, AOX). Allium × cornutum showed a more pronounced response to drought, characterized by higher RWC, stable chlorophyll and carotenoid levels, increased accumulation of free amino acids and phenolic compounds, especially chlorogenic acid and quercetin glycosides, with significant upregulation of the antioxidant genes SOD and CAT. Allium cepa responded more strongly to waterlogging, showing increased amino acid levels, accumulation of quercetin and its glycosides, a marked increase in α-aminobutyric acid (AABA) concentration and higher expression of CAT and SOD. These results show distinct metabolic responses and physiological changes to drought and waterlogging, reflecting stress-specific adjustments under extreme water conditions and contributing to a better understanding of water stress adaptation in Allium species.
Plants, being sessile, must constantly monitor and respond to environmental fluctuations and stressors. Among the diverse signalling modalities (chemical, hydraulic, hormonal), electrical signals stand out for their rapid propagation and capacity to serve as early warning cues. In this review, we examine the concept of electrobiological signatures—distinctive patterns of electrical activity in plants as potential early indicators of stress and adaptation. This review first discusses the fundamental mechanisms such as ion fluxes, membrane transporters, coupling with calcium dynamics, reactive oxygen species (ROS), and cross-talk with hormonal networks. Next, it explores how these signatures manifest under abiotic and biotic stress and how these signatures are linked to downstream adaptive responses. Then, it shifts to agricultural applications, highlighting real-time plant monitoring, phenotyping, stress forecasting, and precision interventions. Finally, plant electrobiology is placed in an ecological context, considering how electrical signalling may mediate plant-plant communication, ecosystem resilience, and bioindication of environmental change. We emphasize that, despite technical and biological challenges such as signal noise, species variability, and decoding specificity, the integration of electrophysiological data with multi-omics approaches and AI analytics offers a promising pathway to transform plant monitoring and management. Therefore, while hurdles remain, the convergence of flexible sensors and AI positions electrobiological signatures as a transformative tool for 21st-century plant science.
Atmospheric deposition is a critical driver of biogeochemical cycling in forest ecosystems. Among the pathways of deposition, throughfall (TF) — precipitation that has interacted with the forest canopy — plays a significant role in the input of atmospheric substances and canopy leachates to the forest floor. We investigated the influence of airborne pollen deposited in TF on its chemical composition across 60 Level II plots of the ICP Forests network in eight European countries. Based on 196 TF samples collected during the 2018 early vegetative season, we identified 53 pollen taxa, with Pinus, Picea, Fagus, and Quercus accounting for 91.4
