Hasil untuk "Plant ecology"

D. Ning, M. Yuan, Linwei Wu et al.

Unraveling the drivers controlling community assembly is a central issue in ecology. Although it is generally accepted that selection, dispersal, diversification and drift are major community assembly processes, defining their relative importance is very challenging. Here, we present a framework to quantitatively infer community assembly mechanisms by phylogenetic bin-based null model analysis (iCAMP). iCAMP shows high accuracy (0.93–0.99), precision (0.80–0.94), sensitivity (0.82–0.94), and specificity (0.95–0.98) on simulated communities, which are 10–160% higher than those from the entire community-based approach. Application of iCAMP to grassland microbial communities in response to experimental warming reveals dominant roles of homogeneous selection (38%) and ‘drift’ (59%). Interestingly, warming decreases ‘drift’ over time, and enhances homogeneous selection which is primarily imposed on Bacillales. In addition, homogeneous selection has higher correlations with drought and plant productivity under warming than control. iCAMP provides an effective and robust tool to quantify microbial assembly processes, and should also be useful for plant and animal ecology. Studies of microbial community assembly mechanisms typically use metrics for turnover within the whole community. Here, the authors develop an alternative approach based on turnover within lineages and dissect mechanistic change in grassland bacterial assembly under experimental warming.

Samir K. Banerjee, Klaus Schlaeppi, M. V. D. van der Heijden

R. Aerts, F. Chapin

W. Finch‐Savage, G. Leubner‐Metzger

Ran Nathan, H. Muller‐Landau

A. Hetherington, F. Woodward

L. Waits, G. Luikart, P. Taberlet

E. Epstein

R. Karban, I. Baldwin

F. Courchamp, T. Clutton‐Brock, B. Grenfell

B. Enquist, James H. Brown, Geoffrey B. West

D. Levey, W. R. Silva, M. Galetti

J. Funk, E. Cleland, K. Suding et al.

S. Levin, H. Muller‐Landau, Ran Nathan et al.

F. Vega, M. Goettel, M. Blackwell et al.

W. Bond, C. Parr

Xiaoqiong Qi, Fei Han, Lansha Luo et al.

Fruit trichomes and pericarp architecture are pivotal for biological defense and postharvest resilience in the genus <i>Actinidia</i>. However, the evolutionary diversity of these structures and the molecular mechanisms governing their development—particularly under the influence of polyploidization—remain poorly understood. We performed a systematic evaluation of 21 <i>Actinidia</i> species and 14 cultivars using scanning electron microscopy (SEM) and histological analysis. To determine the effects of genome doubling, an autotetraploid line was induced from diploid <i>A. chinensis</i> cv. ‘Donghong’, followed by comparative transcriptomic and temporal expression profiling. Morphological characterization identified three distinct evolutionary groups based on fruit surface traits: glabrous, caducous-spotted, and persistent-pubescent. All observed trichomes featured a unique bipartite multicellular architecture. Kiwifruit pericarp thickness (59.8–534.6 μm) was locally reinforced at trichome insertion sites. Among kiwifruit cultivars, polyploidization significantly increased both trichome length and total amount. Transcriptomic analysis revealed 235 differentially expressed genes (DEGs) enriched in hormonal signaling and flavonoid pathways. Two key candidate genes, <i>Achv4p15g023764.t1</i> and <i>Achv4p01g000003.t1</i>, were identified as candidate genes for stage-specific regulators governing early morphogenesis and late maturation. By characterizing the morphological diversity and genetic underpinnings of <i>Actinidia</i> trichome and epidermal variation, this study establishes a potential scientific framework for the targeted kiwifruit breeding of novel kiwifruit cultivars with optimized fruit surface characteristics.

Julio Federico Benites, Diego Ricardo Gutiérrez, Silvana Cecilia Ruiz et al.

Pumpkin (P) production in Santiago del Estero, Argentina, is of high quality. The product is sold whole and fresh, and is traditionally consumed after being cooked in water. Due to its pleasant flavor (semi-sweet), it is widely accepted among consumers, being a potentially versatile product to be consumed fresh or minimally processed (MP). Processing increases food’s susceptibility to microbial spoilage, making it necessary to use sanitizers. In this work, the effect of different application methodologies at different concentrations of rosemary essential oil (REO) on the sensory characteristics and microbiological quality of grated P was evaluated. The product was washed, sanitized, cut, peeled, grated and centrifuged, and then REO was superficially incorporated in two concentrations (4 and 8 μL/mL), applied in three ways: sprayed (TA), immersion (TI) and by strips embedded in EO being adhered to the storage container (TV). The product was subsequently stored at 5 °C in sealed polypropylene bags of 35 μm. In addition, an immersion treatment with NaClO-100 ppm-3 min and a control without any additive were included. Samples were taken at 24 h and 8 days of storage, evaluating mesophilic aerobic microorganisms (MA), psychrophilic (Psy), enterobacteria (E) and mold and yeasts (MY). Sensory evaluation was carried out by trained judges, determining that aroma and flavor were the critical attributes for acceptability. At the end of storage, microbiological analysis showed that REO treatments presented levels of 10⁷ CFU/g, similar to NaCLO treatment, except TI with both concentrations, which was more effective in inhibiting the development of Psy and MY. Regarding aroma evaluation, at 8 days all treatments were acceptable, with the exception of TI and TV (8 μL/mL), while for flavor all treatments were acceptable with the exception of TI for both concentrations. Therefore, the application of TA and TV treatments at the lowest concentration could be considered for further studies to increase the shelf life of MP P.

Xiangjian Tu, Paul C. Struik, Shixian Sun et al.

Grazing can alter the physicochemical properties of soil and quickly influence the composition of microbial communities. However, the effects of grazing intensity on fungal community composition in different soil depth remain unclear. On the Inner Mongolia Plateau, we studied the effects of grazing intensity treatments including no grazing (NG), light grazing (LG), moderate grazing (MG), heavy grazing (HG), and over grazing (OG) on the physicochemical properties and fungal community composition of surface (0–20 cm) and subsurface (20–40 cm) soil layers. The α-diversity of fungi in subsurface soil decreased under the influence of grazing. The relative abundance of Ascomycota in the subsoil was higher than that in the topsoil, while the situation of Basidiomycota was the opposite. This was caused by the differences in the soil carbon (C) environment for the growth of oligotrophic and copiotrophic fungi. In the subsoil, grazing affected nutrient contents such as soil organic matter (SOM) and total nitrogen (TN), resulting in significantly lower relative abundance of Ortierellomycota under LG, HG, and OG than in the NG. HG showed much higher relative abundance of Glomeromycota. Results of a multiple regression tree (MRT) analysis revealed that TN and nitrate nitrogen affected the fungal α-diversity in top- and subsoils, respectively; the main driving factor regulating fungal community changes was soil water content (SWC) in the topsoil, while it was ammonium nitrogen and nitrate nitrogen in the subsoil. The results of our study indicate that grazing changes the soil environment by changing TN, SWC, nitrate nitrogen, ammonium nitrogen, and affects the diversity and community structure of soil fungi. This provides empirical support for coping with the impact of grazing on soil microbiomes in desert steppes.

Doudou Ge, Chongwen Yin, Jiayu Jing et al.

The evolution of phytophagous insects has resulted in the development of feeding specializations that are unique to this group. The majority of current research on insect palatability has concentrated on aspects of ecology and biology, with relatively little attention paid to the role of insect gut symbiotic bacteria. Symbiont bacteria have a close relationship with their insect hosts and perform a range of functions. This research aimed to investigate the relationship between insect host plant range and gut symbiotic bacteria. A synthesis of the extant literature on the intestinal commensal bacteria of monophagous, oligophagous, and polyphagous tephritids revealed no evidence of a positive correlation between the plant host range and the diversity of larval intestinal microbial species. The gut symbionts of same species were observed to exhibit discrepancies between different literature sources, which were attributed to variations in multiple environmental factors. However, following beta diversity analysis, monophagy demonstrated the lowest level of variation in intestinal commensal bacteria, while polyphagous tephritids exhibited the greatest variation in intestinal commensal bacteria community variation. In light of these findings, this study proposes the hypothesis that exclusive or closely related plant hosts provide monophagy and oligophagy with a stable core colony over long evolutionary periods. The core flora is closely associated with host adaptations in monophagous and oligophagous tephritids, including nutritional and detoxification functions. This is in contrast to polyphagy, whose dominant colony varies in different environments. Our hypothesis requires further refinement of the data on the gut commensal bacteria of monophagy and oligophagy as the number of species and samples is currently limited.