Search Results (130)

Root-promoting treatments and media are critical for the clonal propagation of Western pine species, yet long-term data for sugar pine (Pinus lambertiana Dougl.) and ponderosa pine (Pinus ponderosa Dougl. ex C. Lawson) remain limited. This multi-year greenhouse study (2024–2025) used a split-plot greenhouse design to evaluate interactions among four rooting media and various root-promoting treatments, including commercial mixed microbial/biostimulant products and indole-3-butyric acid (IBA). Coconut coir consistently outperformed other media, achieving rooting rates of up to 80% when combined with specific commercial products like Mykos, Dynomyco, or Wildroot. Seasonal timing also proved crucial; winter propagation (January 2025) yielded poor results (<30%) regardless of treatment, consistent with the influence of physiological dormancy. While commercial mixed microbial/biostimulant products were associated with improved rooting, their effectiveness depended on the use of an appropriate substrate. The superior performance of coconut coir is consistent with its physical characteristics (e.g., aeration, water retention), although these properties were not directly measured. Full article

The excessively concentrated ripening period of mulberries causes seasonal surplus. Fruit mulberry (Morus spp.) exhibits the unique trait of “simultaneous flowering and leaf flushing”, rendering budburst timing closely correlated with fruit ripening time. Thus, deciphering the molecular mechanism underlying winter bud dormancy maintenance in fruit mulberry is urgently needed. Herein, an F₁ hybrid population comprising 337 individuals, derived from Morus wittiorum (♀) and ‘322’ (♂), was utilized as research material. Through Bulked Segregant Analysis Sequencing (BSA-Seq), we successfully mapped a dormancy-associated QTL interval designated as LB (Late Burst), spanning 9,990,001–11,990,000 bp on Chromosome 13. Integrating Weighted Gene Co-expression Network Analysis (WGCNA) results, MaSVP was identified as a candidate gene within this interval. Virus-induced gene silencing (VIGS) of MaSVP in winter buds of Morus wittiorum significantly accelerated budburst compared to the control, demonstrating that MaSVP represses winter bud dormancy release and plays a crucial role in regulating dormancy maintenance in fruit mulberry. Dynamic expression profiling of dormancy-related genes revealed that the transcript levels of MaSVP, MaSAPK3, MaCASL2, and MaPYR8 were significantly downregulated (Tukey’s test, p < 0.05) as budburst approached, whereas those of MaFT and MaGA20ox1-D were significantly upregulated (Tukey’s test, p < 0.05). These results indicate that winter bud dormancy maintenance in Morus wittiorum is associated with abscisic acid (ABA) and gibberellin (GA) metabolism. Collectively, this study provides critical insights into the biological basis of winter bud dormancy maintenance in fruit mulberry and offers valuable genetic resources for breeding late-maturing cultivars. Full article

Glyptapanteles porthetriae (Hymenoptera: Braconidae) is a solitary larval endoparasitoid of the spongy moth, Lymantria dispar (Lepidoptera: Erebidae). Previous studies suggested that only the spring generation of the wasp parasitizes early instars of L. dispar, while subsequent generations develop in larvae of unidentified alternative hosts and overwinter exclusively as endoparasitic larvae within these hosts. In a declining outbreak population of L. dispar in Austria, we observed two successive generations of G. porthetriae developing in spongy moth larvae during spring and early summer. The high abundance of parasitoids in the third outbreak year prompted us to test alternative hypotheses proposing a univoltine, monophagous life cycle with strong specialization on L. dispar. We exposed various developmental stages of L. dispar embryonic larvae to wasp females and evaluated potential dormancy induction in G. porthetriae larvae or pupae by assessing developmental parameters and respiratory activity under different environmental conditions. G. porthetriae did not develop from L. dispar individuals exposed in the egg stage, and no dormancy was observed in G. porthetriae developing in L. dispar larvae. These findings disprove the univoltine, monophagous development hypotheses and highlight the reliance of G. porthetriae on suitable alternative hosts to complete its life cycle. Full article

Dryland phenology is tightly constrained by water availability, yet the temporal depth of drought influence remains poorly resolved at regional scales. We analyzed the start and end of season across the Mongolian Plateau using 500 m MODIS kNDVI for 2001–2020 and a phenology-anchored framework that linked multi-timescale SPEI directly to the month of each phenological event. By varying accumulation windows and testing month-wise lags up to twelve months, we mapped pixel-level optimal timescales and sensitivities. Phenology exhibits a clear north–south gradient with weak long-term shifts relative to large interannual variability. Drought acts through two pathways. Multi-month winter–spring moisture deficits delay spring green-up, with the strongest SOS sensitivity to antecedent drought about six to nine months prior. Summer–autumn dryness advances dormancy, and EOS is governed mainly by near-term moisture over the previous one to two months. Responses differ among ecoregions, with deserts and desert steppes the most sensitive and forests and alpine meadows less responsive. These asymmetric timescales imply that prolonged deficits can postpone spring emergence into the following year, whereas short deficits truncate the current season, offsetting warming-driven extensions of growing-season length. Incorporating phenology-anchored, multi-timescale drought indicators can improve model forecasts of dryland carbon–water dynamics and inform monitoring and adaptation in the most water-limited ecoregions. Full article

Global warming has increasingly reduced winter chill accumulation in traditional fruit-growing regions, disrupting dormancy release and bloom synchrony in deciduous fruit crops such as peach (Prunus persica). To evaluate adaptation potential under subtropical conditions, a three-year field study was conducted in central Taiwan using two low-chill cultivars, ‘Tainung No.4 Ruby’ (~100 chilling units, CU) and ‘Tainung No. 7 HongLing’ (~77 CU). Our results demonstrate that both cultivars produced long shoots (>34 nodes), completed vegetative growth by October, and reached natural leaf fall by mid-November. Nonlinear Gompertz and Logistic models accurately described shoot elongation dynamics and growth cessation. Flowering began in mid-January for ‘Tainung No. 7 HongLing’ and mid-February for ‘Tainung No. 4 Ruby’. Seasonal chill accumulation strongly influenced the onset of flower budbreak between apical and basal buds: in the milder 2023–2024 winter (~120 CU), apical–basal onset lags were wider (22 days in ‘Tainung No. 7 HongLing’), whereas in the colder 2024–2025 winter (~280 CU), these lags shortened (14 days). Notably, ‘Tainung No. 4 Ruby’ maintained a consistent apical–basal onset lag between seasons, indicating greater positional stability under variable chilling. Field-estimated CU thresholds for flower budbreak exceeded the reported chilling requirements, suggesting reduced chilling efficiency under fluctuating subtropical winter temperatures. These results demonstrate that integrating shoot growth, leaf fall timing, and chill–heat accumulation provides a phenology-informed framework for cultivar selection and orchard scheduling, thereby enhancing climate resilience of peach production in warm-winter regions. Full article

Globally, biodiversity is declining, meaning that many endemic plants are under threat; therefore, it is essential to develop conservation strategies. Scutellaria indica var. coccinea has great potential as an ornamental ground cover plant, but it is a plant that requires ex situ conservation. This study was conducted in order to investigate the seed germination characteristics and classify the dormancy type of S. indica var. coccinea seeds, with the aim of developing mass propagation protocols for ex situ conservation and preservation of their genetic diversity. Fresh and mature seeds of S. indica var. coccinea are in a dormant state, which is released by low temperatures during winter, resulting in radicle and seedling emergence the following spring. At the time of dispersal, the seeds had fully developed embryos, and the seed coat was permeable. When the seeds were incubated under four different temperature regimes (4, 15/6, 20/10, or 25/15 °C), they showed a low germination percentage (≤20%), indicating that a substantial proportion of the seeds remained in a dormant state. In the cold stratification experiment (0, 4, 8, or 12 weeks at 4 °C), germination increased, and the time required for germination shortened as the duration of cold treatment lengthened. This suggests that low temperatures are the primary environmental signal that induces germination. In the gibberellic acid (GA₃) treatment (GA₃ 0, 10, 100, or 1000 mg·L⁻¹), relatively high concentrations (100 and 1000 mg·L⁻¹) were effective in promoting germination. The highest germination was obtained in GA₃ 1000 mg·L⁻¹ with 100.0%, which is about 7 times higher than the control (13.6%). Therefore, seeds of S. indica var. coccinea were classified as having non-deep physiological dormancy (PD). Additionally, because the minimum germinable temperature range of the seeds was extended to lower temperatures, the seeds were classified as having type 2 non-deep PD. Full article

Pear (Pyrus pyrifolia) is an important deciduous fruit tree that requires a specific period of low-temperature accumulation to trigger spring flowering. The warmer winter caused by global warming has led to insufficient winter chilling, disrupting floral initiation and significantly reducing pear yields in Southern China. In this study, we integrated targeted phytohormone metabolomics, full-length transcriptomics, and proteomics to explore the regulatory mechanisms of dormancy in ‘Mixue’, a pear cultivar with an extremely low chilling requirement. Comparative analyses across the multi-omics datasets revealed 30 differentially abundant phytohormone metabolites (DPMs), 2597 differentially expressed proteins (DEPs), and 7722 differentially expressed genes (DEGs). Integrated proteomic and transcriptomic expression clustering analysis identified five members of the dormancy-associated MADS-box (DAM) gene family among dormancy-specific differentially expressed proteins (DEPs) and differentially expressed genes (DEGs). Phytohormone correlation analysis and cis-regulatory element analysis suggest that DAM genes may mediate dormancy progression by responding to abscisic acid (ABA), gibberellin (GA), and salicylic acid (SA). A dormancy-associated transcriptional regulatory network centered on DAM genes and phytohormone signaling revealed 35 transcription factors (TFs): 19 TFs appear to directly regulate the expression of DAM genes, 18 TFs are transcriptionally regulated by DAM genes, and two TFs exhibit bidirectional regulatory interactions with DAM. Within this regulatory network, we identified a novel pathway involving REVEILLE 6 (RVE6), DAM, and CONSTANS-LIKE 8 (COL8), which might play a critical role in regulating bud dormancy in the ‘Mixue’ low-chilling pear cultivar. Furthermore, lncRNAs ONT.19912.1 and ONT.20662.7 exhibit potential cis-regulatory interactions with DAM1/2/3. This study expands the DAM-mediated transcriptional regulatory network associated with bud dormancy, providing new insights into its molecular regulatory mechanisms in pear and establishing a theoretical framework for future investigations into bud dormancy control. Full article

The abiotic stresses associated with spring/fall freezes and extreme winter cold cause significant economic losses in blueberry production. These problems are exacerbated by climate change and increasingly erratic weather patterns. Developing freeze-tolerant blueberry cultivars with optimized cold hardiness, chilling requirement, and flowering and fruiting phenology holds promise for mitigating the risk of these weather-related damages. These weather-resilient cultivars will ensure the long-term productivity and sustainability of the blueberry industry. The focus of this review is to present the current understanding of the major components of genetic breeding for blueberry freeze tolerance, i.e., phenotyping, genotyping, genetic association analysis, and marker development. The advancement in gene regulation and corresponding proteomic changes upon cold acclimation, dormancy, de-acclamation, and flowering and fruiting aids in the understanding of the adaptive stress response in blueberries. A wide range of genetic diversity in freeze tolerance and phenological traits has been identified among cultivated and wild blueberry relatives. Significant efforts have been made to phenotype freeze tolerance, chilling requirement, and flower and fruit development in both field and controlled environmental conditions. Recent studies emphasize the need for high-throughput, image-based phenotyping of blueberry flower development to improve the precision and efficiency of selecting freeze-resilient genotypes. In addition, advancements in blueberry genomics and pangenome resources expanded the potential of variant calling and high-density linkage map construction. Genetic association studies have identified QTL regions linked to freeze tolerance in blueberries, providing valuable targets for selection. The implementation of these advanced genomic tools and high-throughput phenotyping methodology will accelerate the development of weather-resilient blueberry cultivars. Full article

The temperate evergreen needleleaf forest (ENF), primarily composed of Mongolian Scots pine (Pinus sylvestris var. mongolica), plays a pivotal role in the “The Great Green Wall” Shelterbelt Project in northern China as a major species for windbreak and sand fixation. Solar-induced chlorophyll fluorescence (SIF) has emerged as a revolutionary remote sensing signal for quantifying photosynthetic activity and gross primary production (GPP) at the ecosystem scale. Meanwhile, eddy covariance (EC) technology has been widely employed to obtain in situ GPP estimates. Although a linear relationship between SIF and GPP has been reported in various ecosystems, it is mainly derived from satellite SIF products and flux-tower GPP observations, which are often difficult to align due to mismatches in spatial and temporal resolution. In this study, we analyzed synchronous high-frequency SIF and EC-derived GPP measurements from a Mongolian Scots pine plantation during the seasonal transition (August–December). The results revealed the following. (1) The ENF acted as a net carbon sink during the observation period, with a total carbon uptake of 100.875 gC·m⁻². The diurnal dynamics of net ecosystem exchange (NEE) exhibited a “U”-shaped pattern, with peak carbon uptake occurring around midday. As the growing season progressed toward dormancy, the timing of CO₂ uptake and release gradually shifted. (2) Both GPP and SIF peaked in September and declined thereafter. A strong linear relationship between SIF and GPP (R² = 0.678) was observed, consistent across both diurnal and sub-daily scales. SIF demonstrated higher sensitivity to light and environmental changes, particularly during the autumn–winter transition. Cloudy and rainy conditions significantly affect the relationship between SIF and GPP. These findings highlight the potential of canopy SIF observations to capture seasonal photosynthesis dynamics accurately and provide a methodological foundation for regional GPP estimation using remote sensing. This work also contributes scientific insights toward achieving China’s carbon neutrality goals. Full article

Background/Objectives: In perennial plants, developing floral buds survive winter through entering a dormant state, which is induced by low temperature and abscisic acid (ABA). ABA performs vital functions in the dormancy process. ABA-insensitive 5 (ABI5) transcription factor is a key regulator in the ABA signaling pathway. However, little is known about the regulation of ABI5 in the winter dormancy of sweet cherries. Methods: We identified the sweet cherry ABI5 gene and its expression changes using gene cloning and qRT-PCR. Additionally, we validated the interaction between PavABI5 and PavCIG1/2 using Yeast One-Hybrid and Dual-Luciferase Assays. Results: In this study, we identified a basic leucine zipper (bZIP) family gene ABI5 from the sweet cherry, which was closely related to PduABI5 from Prunus dulcis, PpABI5 from Prunus persica, PmABI5 from Prunus mume, and ParABI5 from Prunus armeniaca, through phylogenetic tree analysis. The seasonal expression pattern showed that the PavABI5 level was increased during the winter dormancy stage and induced by exogenous ABA. Specifically, we found that the expression of cherry cold-induced genes (PavCIG1/2) was positively correlated with PavABI5 expression. Furthermore, PavABI5 directly bound to the ABRE elements in the PavCIG1/2 promoters to activate their expression. We further confirmed that the dormancy-associated MADS-box (DAM) genes DAM4 and DAM5 function downstream of the ABA signaling pathway to regulate bud dormancy in sweet cherries. Conclusions: Our findings suggest a putative regulatory model of ABA-mediated bud-dormancy with PavABI5. Full article

This study investigated seed storage behavior and seedling development patterns in the genus Phoenix L. (Arecaceae), addressing the knowledge gap regarding orthodox versus recalcitrant characteristics in these ecologically and economically significant palms. We examined the germination capacity and subsequent growth in 31 seed samples from various Phoenix species stored for up to 10 years at approximately 5 °C, at the Germplasm Bank at the Escuela Politécnica Superior de Orihuela, comprising 465 seeds monitored over a one-year period. The seed germination trials involved planting seeds in pots placed in an open-air greenhouse after ambient temperatures consistently exceeded 20 °C, typically after mid-June. Phoenix dactylifera, P. canariensis, P. theophrasti, the hybrid P. dactylifera × P. canariensis, and P. × “Palmeri” demonstrated orthodox seed storage behavior, maintaining viability for up to nine years. Conversely, P. sylvestris, P. pusilla, P. rupicola, and P. loureiroi consistently failed to germinate despite previous germination success, suggesting potential recalcitrant characteristics. Statistical analyses revealed that species identity and geographic origin exerted greater influence on germination success than seed age. Seedling development exhibited a conserved seasonal pattern across all species, with synchronized leaf emergence in September and March–July, followed by winter dormancy. Significant intraspecific variation was observed, particularly within P. dactylifera varieties, in both leaf production and final leaf length. These findings provide valuable insights into germplasm preservation and cultivation strategies, demonstrating that while some Phoenix species are suitable for long-term seed banking, others may require alternative conservation approaches. The observed species-specific and variety-specific differences offer important selection criteria for horticultural applications and conservation efforts. Full article

Seed propagation is the primary means of reproducing many native and endemic species, including garberia [Garberia heterophylla (W. Bartram) Merrill & F. Harper]. This attractive pollinator plant, native to Florida, is scarcely found in nursery production and largely unknown to the gardening community. To better understand the seed biology of garberia, a series of experiments were conducted to evaluate the effects of population on seed viability and germination response to four seasonal temperatures, as well as the effects of time on seed storability. Initial seed viability was 49% and 60% for Central and North Florida populations, respectively. Seeds germinated readily, indicating non-dormancy, with significant effects of population and temperature observed. Overall, on day 28, a greater germination proportion was observed from seeds collected from North Florida than Central Florida across temperatures, except for winter (11/22 °C), where responses were similar. The greatest germination proportion for seeds collected from North Florida was observed at 15/27 °C (fall) and 19/29 °C (spring), whereas the greatest germination from Central Florida was observed at 11/22 °C (winter), with the steepest decline observed at summer temperatures (24/33 °C). Further, it was observed that garberia seeds are intolerant of long-term storage, losing viability as early as 3 months under conventional cold or room temperature storage and decreasing substantially more after 6 months. These findings contribute to the overall understanding of the seed biology of underutilized species such as garberia, key to the development of efficient and reliable propagation systems for our nursery industry. Full article

Theanine, a unique non-protein amino acid, is specifically accumulated in tea plants during winter. This study explored the theanine accumulation patterns in ‘Longjing 43’ and ‘Huangjinya’ under different N supply conditions and analyzed the expression of genes involved in theanine biosynthesis during winter dormancy. We found that the two tea plant cultivars shared similar theanine accumulation patterns in winter. After 30 d of cultivation with various N forms and N deficiency, the theanine content in the tissues of both cultivars was highest in the control group, followed by NH₄⁺ treatment. Furthermore, we noted that root growth of tea plants was inhibited to varying degrees under different N sources and N-deficient conditions. Gene expression analysis revealed that both N forms can induce the transcription of key genes, including CsADC, CsALT, CsCuAO, CsGDH2, CsPAO, CsNiR, CsNR, and CsTS1 in ‘Longjing 43’ and ‘Huangjinya’. The expression of these genes was strongly correlated with theanine levels under the N treatments. The winter theanine accumulation was finely tuned by the interplay of multiple related genes, with expression levels varying across different cultivars and tissues. Full article

Cold climate viticulture is challenged by climatic variability, including increased frost risk, shorter growing seasons, and unpredictable weather events that impact vine productivity and grape quality. Global warming is altering traditional viticulture zones, prompting the exploration of new regions for grape cultivation, the selection of climate-resilient cultivars, and the implementation of adaptive practices. This review synthesizes recent advances in adaptive viticulture practices and plant growth regulator applications, highlighting novel molecular and physiological insights on cold stress resilience and berry quality. Key strategies include delayed winter pruning to mitigate frost damage, osmoprotectant application to improve freeze tolerance, and canopy management techniques (cluster thinning and defoliation) to enhance berry ripening and wine composition. Their effectiveness depends on vineyard microclimate, soil properties and variety-specific physiological response. Cover cropping is examined for its role in vine vigor regulation, improving soil microbial diversity, and water retention, though its effectiveness depends on soil type, participation patterns, and vineyard management practices. Recent transcriptomic and metabolomic studies have provided new regulatory mechanisms in cold stress adaptation, highlighting the regulatory roles of abscisic acid, brassinosteroids, ethylene, and salicylic acid in dormancy induction, oxidative stress response, and osmotic regulation. Reflective mulch technologies are currently examined for their ability to enhance light interception, modulating secondary metabolite accumulation, improving technological maturity (soluble solids, pH, and titratable acidity) and enhancing phenolic compounds content. The effectiveness of these strategies remains highly site-specific, influenced by variety selection and pruning methods particularly due to their differences on sugar accumulation and berry weight. Future research should prioritize long-term vineyard trials to refine these adaptive strategies, integrate genetic and transcriptomic insights into breeding programs to improve cold hardiness, and develop precision viticulture tools tailored to cold climate vineyard management. Full article

The flowering and fruiting of sweet cherry (Prunus avium L.) depend on precise synchronization with seasonal events. During harsh autumn and winter conditions, floral buds enter dormancy to protect and prepare for the productive season. Dormancy release occurs after exposure to genotype-specific chilling temperatures, an event in which epigenetic reprogramming triggers further metabolic and gene expression activation. Similarly, several Arabidopsis ecotypes require chilling (vernalization) to transition from vegetative to floral states. At vernalization’s end, the decrease in the repressor complex formed by SHORT VEGETATIVE PHASE (SVP) and FLOWERING LOCUS C (FLC) allows FLOWERING LOCUS T (FT) to induce flowering. However, this alone does not fully explain the process. MicroRNAs (miRNAs) play a crucial role in gene regulation during plant development and environmental interactions, and miR396’s role during flower development and vernalization has been described in some plant species, although not for sweet cherry dormancy. We used ‘Regina’, a high-chill sweet cherry variety, to identify candidate small RNA molecules throughout dormancy, resulting in the detection of miR396. The transcript expression levels of the putative miRNA target genes were evaluated through quantitative PCR analyses of dormant buds. Additionally, an artificial sweet cherry miR396 was used to transform Arabidopsis Edi-0, a vernalization-requiring ecotype. Ectopic expression of this artificial molecule partially mirrored the effect on target genes observed in dormant buds and, more importantly, led to vernalization-independent flowering. Artificial miR396 expression also resulted in decreased FLC and increased SVP and FT transcript levels. These results could pave the way for future studies on the involvement of miR396 in the regulation of dormancy and flowering, with potential applications in improving crop resilience and productivity. Full article