Search results for " growth"
showing 10 items of 4263 documents
The Philippine Agriculture: Weaknesses and Controversies
2017
The sugarcane plantations of Negros Island epitomize the huge inequalities in the Philippine countryside. Landlords have controlled vast estates, the haciendas, since the Spanish colonial period. Despite the pressure of peasant associations, revolutionary agrarian movements (Huks, then the communist NPA) and the church support for poor farmers, most efforts to implement a substantial agrarian reform, including in the Marcos period and the CARP of Corazon Aquino, have failed in reducing inequities and improving the life of poor peasants in the country. Hacienda Luisita, a property of the Aquino family, illustrates the difficulties to implement a true agrarian reform. The Philippines hence ap…
Rhizoctonia solani AG 11 isolated for the first time from sugar beet in Poland
2020
Abstract Two isolates of Rhizoctonia solani AG11 were isolated from sugar beet seedlings from South-west Poland. Both isolates gave C2 reactions in anastomose pairings with the tester isolates of AG11. The membership of both isolates to AG11 was confirmed by analysis of pectic isozyme profiles, and by verification that the internal transcribed spacer sequences of both isolates matched the references in the GenBank database. Both AG11 isolates formed white-beige to creamy-colored mycelium with wide concentric zonation. One of them formed light-colored sclerotia. The average daily rate of hyphal growth at 21 °C was 22.8 mm and 22.6 mm on PDA. They were mildly pathogenic to sugar beet seedling…
Daphnia invest in sexual reproduction when its relative costs are reduced
2018
The timing of sex in facultatively sexual organisms is critical to fitness, due to the differing demographic consequences of sexual versus asexual reproduction. In addition to the costs of sex itself, an association of sex with the production of dormant life stages also influences the optimal use of sex, especially in environments where resting eggs are essential to survive unfavourable conditions. Here we document population dynamics and the occurrence of sexual reproduction in natural populations of Daphnia magna across their growing season. The frequency of sexually reproducing females and males increased with population density and with decreasing asexual clutch sizes. The frequency of…
Founder effects drive the genetic structure of passively dispersed aquatic invertebrates
2018
Populations of passively dispersed organisms in continental aquatic habitats typically show high levels of neutral genetic differentiation, despite their high dispersal capabilities. Several evolutionary factors, including founder events and local adaptation, and life cycle features such as high population growth rates and the presence of propagule banks, have been proposed to be responsible for this paradox. Here, we have modeled the colonization process in these organisms to assess the impact of migration rate, growth rate, population size, local adaptation and life-cycle features on their population genetic structure. Our simulation results show that the strongest effect on population st…
Transcriptomic responses to biotic stresses in Malus x domestica: a meta-analysis study.
2017
AbstractRNA-Seq analysis is a strong tool to gain insight into the molecular responses to biotic stresses in plants. The objective of this work is to identify specific and common molecular responses between different transcriptomic data related to fungi, virus and bacteria attacks in Malus x domestica. We analyzed seven transcriptomic datasets in Malus x domestica divided in responses to fungal pathogens, virus (Apple Stem Grooving Virus) and bacteria (Erwinia amylovora). Data were dissected using an integrated approach of pathway- and gene- set enrichment analysis, Mapman visualization tool, gene ontology analysis and inferred protein-protein interaction network. Our meta-analysis revealed…
Nitric oxide: a multitask player in plant–microorganism symbioses
2016
Symbiosis is a close and often long-term interaction between two different biological organisms, i.e. plants or fungi and microorganisms. Two main types of plant–microorganism interactions, mutualistic and cooperative, have been categorized. Mutualistic interactions, including nitrogen-fixing and mycorrhizal symbioses, refer to mostly obligate relationships between a host plant and a symbiont microorganism. Cooperative interactions correspond to less obligate and specific relationships. They involve microorganisms, referred to as plant growth-promoting rhizobia (PGPR), able to colonize root surface or inner tissues. Lichens are symbiotic associations of host fungi and photosynthetic partner…
Root growth compensates for molar wear in adult goats (Capra aegagrus hircus)
2018
One reason for the mammalian clade’s success is the evolutionary diversity of their teeth. In herbivores, this is represented by high‐crowned teeth evolved to compensate for wear caused by dietary abrasives like phytoliths and grit. Exactly how dietary abrasives wear teeth is still not understood completely. We fed four different pelleted diets of increasing abrasiveness (L: Lucerne; G: grass; GR: grass and rice husks; GRS: grass, rice husks, and sand) to four groups of a total of 28 adult goats, all with completely erupted third molars, over a six‐month period. Tooth morphology was captured by medical computed tomography scans at the beginning and end of the controlled feeding experiment, …
The phosphorylated pathway of serine biosynthesis links plant growth with nitrogen metabolism
2021
Abstract Because it is the precursor for various essential cellular components, the amino acid serine is indispensable for every living organism. In plants, serine is synthesized by two major pathways: photorespiration and the phosphorylated pathway of serine biosynthesis (PPSB). However, the importance of these pathways in providing serine for plant development is not fully understood. In this study, we examine the relative contributions of photorespiration and PPSB to providing serine for growth and metabolism in the C3 model plant Arabidopsis thaliana. Our analyses of cell proliferation and elongation reveal that PPSB-derived serine is indispensable for plant growth and its loss cannot b…
What has been thought and taught on the lunar influence on plants in agriculture? Perspective from physics and biology
2020
This paper reviews the beliefs which drive some agricultural sectors to consider the lunar influence as either a stress or a beneficial factor when it comes to organizing their tasks. To address the link between lunar phases and agriculture from a scientific perspective, we conducted a review of textbooks and monographs used to teach agronomy, botany, horticulture and plant physiology; we also consider the physics that address the e ects of the Moon on our planet. Finally, we review the scientific literature on plant development, specifically searching for any direct or indirect reference to the influence of the Moon on plant physiology. We found that there is no reliable, science-based evi…
Holm Oak Somatic Embryogenesis: Current Status and Future Perspectives
2019
Quercus ilex (holm oak) is one of the most representative trees in the Mediterranean basin, but now the sustainability of its ecosystems is at serious risk due to the lack of natural regeneration and to the presence of a severe disease called oak decline that has caused the death of thousands of trees. The application of biotechnological tools, such as somatic embryogenesis, allows programs of genetic improvement of the species to be speeded up and helps in the conservation of its ecosystems. Somatic embryogenesis is currently considered one of the main biotechnological techniques that has demonstrated significant benefits when has applied to forest tree species, providing significant advan…