Hasil untuk "Plant ecology"

S. Jacquemoud, W. Verhoef, F. Baret et al.

F. C. James, C. McCulloch

D. Tilman

D. Richardson, P. Pyšek, M. Rejmánek et al.

M. Loreau, A. Hector

R. Aerts, F. Chapin

Jiquan Chen, S. Saunders, T. Crow et al.

Patrick H. Martin, C. Canham, P. Marks

R. Raguso

P. Adler, E. Seabloom, E. Borer et al.

D. Johnston-Monje, M. Raizada

Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte) to modern maize (corn) and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP) of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with γ-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed isolate, Enterobacter asburiae, was able to exit the root and colonize the rhizosphere. Conservation and diversity in Zea-microbe relationships are discussed in the context of ecology, crop domestication, selection and migration.

J. Bever, Thomas G. Platt, Elise R Morton

J. Keeley, W. Bond, R. Bradstock et al.

S. Simard, Kevin J. Beiler, M. Bingham et al.

Daniel Mejer Christensen, Katja Stougård Jørgensen, Josefine Palsgaard Wyrtz et al.

Research in Human-Computer Interaction (HCI) has shown that caring for others, including both humans (e.g., close friends) and computers (e.g., Tamagotchi), can have a positive effect on people's wellbeing. However, we know less about the potential role of conversational AI in such settings. In this work, we explore how AI chatbots can support plant care and, in turn, positively influence people's well-being. We developed a mobile application that allows users to `talk' to their plants via chatbots. We evaluated the application with ten participants and conducted semi-structured interviews based on Seligman's PERMA model, which identifies pillars of psychological well-being. Our findings suggest positive effects, with participants reflecting on a sense of connection to their plants and corresponding feelings of accomplishment. While our findings suggest that participants were generally positive about the app, they also raised concerns about the diverse preferences and expectations of users regarding interactions with chatbots representing plants.

Gary León-Burgos, Carmen Marín-Tello, Roxana Mendoza-Mendocilla et al.

Se estudió un extracto acuoso de taninos hidrolizables del pericarpio de plantas de tara utilizando frutos de vainas recolectadas en las tierras altas de la región La Libertad en el norte del Perú. La presencia de taninos en el extracto se verificó mediante el uso de la prueba de tricloruro de hierro (FeCl₃) y se calculó una concentración de 45% de taninos análogos al ácido gálico utilizando un método espectrofotométrico. El extracto se aplicó sobre ooquistes vivos de Eimeria sp. presentes en la vacuna viva EVANT® (esta formulación contiene especies de coccidios con patogenicidad específica para aves de corral). Los ooquistes fueron expuestos a diez tratamientos con concentraciones aumentadas y dos controles con cinco réplicas para cada uno. La inspección microscópica se realizó regularmente después del tiempo de exposición con el objetivo de detectar la integridad de la membrana celular. Los resultados muestran que el mayor número de ooquistes afectados por los extractos se produjo a una concentración de 50000 ppm después de 48horas de exposición in vitro, por lo que sugiere que el extracto de tanino de tara tiene propiedades anticoccidiales sobre los parásitos que afectan a las aves de corral. Se recomiendan estudios adicionales para investigar el efecto de los extractos de tara sobre los ovocitos in vivo, y su eventual incorporación como ingrediente en alimentos para aves de producción avícola.

Diego Villar-Morales, Alejandra Moreno-Letelier, Marcelo Rodrigo Pace et al.

Background and aims – Chamaedorea is the largest genus of neotropical palms distributed mainly in lowland rainforests and montane cloud forests from Mexico to Bolivia. Species delimitation in this genus remains problematic due to high morphological variation and inconsistent taxonomic treatment of such variation. Chamaedorea elatior, a climbing species from southern Mexico and northern Central America, exemplifies these challenges with several historical synonyms and informally recognized morphotypes. This study evaluates the morphological variation in vegetative characters between this species’ most characteristic two morphotypes, cespitose and solitary, to evaluate their taxonomic distinctiveness. Material and methods – Six populations of C. elatior were sampled in Mexico and Guatemala, representing both solitary and cespitose morphotypes. Thirteen morphological leaf characters were measured from mature individuals. Data were examined using univariate and multivariate analyses (NMDS, k-means clustering, PCA, MANOVA, LDA) to evaluate morphological variation between the morphotypes and populations. Discriminant analyses were also used to assess classification into either morphotype. Key results – Univariate analyses revealed significant differences between morphotypes in most measured characters, mainly those associated with leaf size. Similarity analyses recovered both morphotypes as being distinct from each other. PCA showed notable separation of the morphotypes along the first component that summarized leaf and median leaflet size. Both MANOVA and LDA confirmed significant differences between morphotypes and resulted in high accuracy classification. Conclusion – Leaf morphology clearly distinguishes the solitary and cespitose morphotypes of C. elatior, supporting their potential delimitation as separate species. The branching habit of the cespitose form further reinforces this distinction. While current results support species-level recognition, additional evidence from reproductive characters, niche, and genetic divergence is recommended to confirm a possible species delimitation.

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.

Viktor Kozák, Jan Chudoba, Libor Přeučil

An accurate and up-to-date model of a photovoltaic (PV) power plant is essential for its optimal operation and maintenance. However, such a model may not be easily available. This work introduces a novel approach for PV power plant mapping based on aerial overview images. It enables the automation of the mapping process while removing the reliance on third-party data. The presented mapping method takes advantage of the structural layout of the power plants to achieve detailed modeling down to the level of individual PV modules. The approach relies on visual segmentation of PV modules in overview images and the inference of structural information in each image, assigning modules to individual benches, rows, and columns. We identify visual keypoints related to the layout and use these to merge detections from multiple images while maintaining their structural integrity. The presented method was experimentally verified and evaluated on two different power plants. The final fusion of 3D positions and semantic structures results in a compact georeferenced model suitable for power plant maintenance.

Joseph Bejjani, Chase Van Amburg, Chengrui Wang et al.

We explore how physical scale and population size shape the emergence of complex behaviors in open-ended ecological environments. In our setting, agents are unsupervised and have no explicit rewards or learning objectives but instead evolve over time according to reproduction, mutation, and selection. As they act, agents also shape their environment and the population around them in an ongoing dynamic ecology. Our goal is not to optimize a single high-performance policy, but instead to examine how behaviors emerge and evolve across large populations due to natural competition and environmental pressures. We use modern hardware along with a new multi-agent simulator to scale the environment and population to sizes much larger than previously attempted, reaching populations of over 60,000 agents, each with their own evolved neural network policy. We identify various emergent behaviors such as long-range resource extraction, vision-based foraging, and predation that arise under competitive and survival pressures. We examine how sensing modalities and environmental scale affect the emergence of these behaviors and find that some of them appear only in sufficiently large environments and populations, and that larger scales increase the stability and consistency of these emergent behaviors. While there is a rich history of research in evolutionary settings, our scaling results on modern hardware provide promising new directions to explore ecology as an instrument of machine learning in an era of increasingly abundant computational resources and efficient machine frameworks. Experimental code is available at https://github.com/jbejjani2022/ecological-emergent-behavior.