Intrapopulation Differentiation by the Rates of Rosette Growth and Individual Plant Development in Narrow-Leaved Hawk’s Beard (Crepis tectorum L.): Aftereffects of Long-Term Stress

2005 ◽  
Vol 36 (4) ◽  
pp. 219-226 ◽  
Author(s):  
M. R. Trubina
Keyword(s):  
Plant Development ◽  
Individual Plant ◽  
Crepis Tectorum

scholarly journals Two decades of research with the GreenLab model in agronomy

2020 ◽  
Author(s):  
Philippe de Reffye ◽  
Baogang Hu ◽  
Mengzhen Kang ◽  
Véronique Letort ◽  
Marc Jaeger
Keyword(s):  
Research Effort ◽  
Mathematical Formulation ◽  
Research Work ◽  
Current Status ◽  
Individual Plant ◽  
Mathematical Framework ◽  
Plant Structure ◽  
Experimental Protocols ◽  
The Individual

Abstract Background With up to 200 published contributions, the GreenLab mathematical model of plant growth, developed since 2000 under Sino-French co-operation for agronomic applications, is descended from the structural models developed in the AMAP unit that characterize the development of plants and encompass them in a conceptual mathematical framework. The model also incorporates widely recognized crop model concepts (thermal time, light use efficiency and light interception), adapting them to the level of the individual plant. Scope Such long-term research work calls for an overview at some point. That is the objective of this review paper, which retraces the main history of the model’s development and its current status, highlighting three aspects. (1) What are the key features of the GreenLab model? (2) How can the model be a guide for defining relevant measurement strategies and experimental protocols? (3) What kind of applications can such a model address? This last question is answered using case studies as illustrations, and through the Discussion. Conclusions The results obtained over several decades illustrate a key feature of the GreenLab model: owing to its concise mathematical formulation based on the factorization of plant structure, it comes along with dedicated methods and experimental protocols for its parameter estimation, in the deterministic or stochastic cases, at single-plant or population levels. Besides providing a reliable statistical framework, this intense and long-term research effort has provided new insights into the internal trophic regulations of many plant species and new guidelines for genetic improvement or optimization of crop systems.

The Need for a New Approach to Grazing Management - Is Cell Grazing the Answer?

1996 ◽  
Vol 18 (2) ◽  
pp. 327 ◽  
Author(s):  
JM Earl ◽  
CE Jones
Keyword(s):  
Ground Cover ◽  
Dry Weight ◽  
Grazing Pressure ◽  
Individual Plant ◽  
South Wales ◽  
Continuous Grazing ◽  
Adverse Environmental Conditions ◽  
The Stability ◽  
A Site

With any grazing method, the grazing pressure applied to an individual plant is a site, stock density and time dependent variable and the diet selection hierarchy of grazing animals is to the disadvantage of the most palatable and actively growing pasture components. The greater the differences in palatability and abundance among the components of a sward, and the lower the stock density, the greater the variation in the grazing pressure exerted. These effects are heightened when animals are set-stocked under adverse environmental conditions. This paper reports the comparative effects of cell grazing and continuous grazing on pasture composition on three properties on the Northern Tablelands of New South Wales. The basal diameters, relative frequency and contribution to dry weight of the most desirablelpalatable species at each site were found to remain constant or to increase under cell grazing, while declining significantly under continuous stocking. The converse was true for the least palatable components of the pasture, which declined significantly under cell grazing but changed little under continuous grazing. Percentage ground cover was significantly higher after two years of cell grazing than under continuous grazing. These changes in pasture composition may have long-term benefits with respect to erosion control, nutrient cycling, hydrological function and the stability of animal production at the cell grazed sites.

scholarly journals The Future of Essentially Derived Variety (EDV) Status: Predominantly More Explanations or Essential Change

2021 ◽  
Author(s):  
John Stephen C. Smith
Keyword(s):  
Risk Taking ◽  
Current Approach ◽  
Individual Plant ◽  
Crop Species ◽  
Technological Advances ◽  
Essential Change ◽  
Essentially Derived Varieties ◽  
Perverse Incentives ◽  
New Varieties

This review examines the categorization of Essentially Derived Varieties (EDV) introduced in the 1991 revision of the Convention of the Union internationale pour la protection des obtentions végétales (UPOV). Challenges in the implementation of the concept and progress made on a crop-by-crop basis to provide greater clarity and more efficient implementation are reviewed. The current approach to EDV remains valid provided i) clarity on thresholds can be achieved including through resource intensive research on an individual crop species basis and ii) that threshold clarity does not lead to perverse incentives to avoid detection of essential derivation. However, technological advances leading to new varieties resulting from the simultaneous introduction or change in expression of more than “a few” genes will so challenge the concept to require a new Convention. Revision could include deletion of the concept of essential derivation and revision on a crop-by-crop basis of the breeder exception. Countries that allow utility patents for individual plant varieties per se should consider removing that possibility unless plant breeders utilize those encouragements for risk taking and investment to broaden the germplasm base upon which the long-term sustainability of plant breeding resides.

Riparian plant species differ in sensitivity to both the mean and variance in groundwater stores

2020 ◽  
Vol 13 (5) ◽  
pp. 621-632
Author(s):  
Kelly A Steinberg ◽  
Kim D Eichhorst ◽  
Jennifer A Rudgers
Keyword(s):  
Plant Species ◽  
Groundwater Resources ◽  
Plant Ecology ◽  
Individual Plant ◽  
Groundwater Levels ◽  
Sensitivity Functions ◽  
Mean And Variance ◽  
The Mean ◽  
Riparian Plant

Abstract Aims Determining the ecological consequences of interactions between slow changes in long-term climate means and amplified variability in climate is an important research frontier in plant ecology. We combined the recent approach of climate sensitivity functions with a revised hydrological ‘bucket model’ to improve predictions on how plant species will respond to changes in the mean and variance of groundwater resources. Methods We leveraged spatiotemporal variation in long-term datasets of riparian vegetation cover and groundwater levels to build the first groundwater sensitivity functions for common plant species of dryland riparian corridors. Our results demonstrate the value of this approach to identifying which plant species will thrive (or fail) in an increasingly variable climate layered with declining groundwater stores. Important Findings Riparian plant species differed in sensitivity to both the mean and variance in groundwater levels. Rio Grande cottonwood (Populus deltoides ssp. wislizenii) cover was predicted to decline with greater inter-annual groundwater variance, while coyote willow (Salix exigua) and other native wetland species were predicted to benefit from greater year-to-year variance. No non-native species were sensitive to groundwater variance, but patterns for Russian olive (Elaeagnus angustifolia) predict declines under deeper mean groundwater tables. Warm air temperatures modulated groundwater sensitivity for cottonwood, which was more sensitive to variability in groundwater in years/sites with warmer maximum temperatures than in cool sites/periods. Cottonwood cover declined most with greater intra-annual coefficients of variation (CV) in groundwater, but was not significantly correlated with inter-annual CV, perhaps due to the short time series (16 years) relative to cottonwood lifespan. In contrast, non-native tamarisk (Tamarix chinensis) cover increased with both intra- and inter-annual CV in groundwater. Altogether, our results predict that changes in groundwater variability and mean will affect riparian plant communities through the differential sensitivities of individual plant species to mean versus variance in groundwater stores.

scholarly journals IPR 1.0: an efficient method for calculating solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities

2014 ◽  
Vol 7 (4) ◽  
pp. 1357-1376
Author(s):  
Y. Zhang ◽  
W. Chen ◽  
J. Li
Keyword(s):  
Climate Change ◽  
Solar Radiation ◽  
Plant Communities ◽  
Woody Plant ◽  
Diffuse Radiation ◽  
Individual Plant ◽  
Vegetation Models ◽  
Composition Structure ◽  
Distribution Composition

Abstract. Climate change may alter the spatial distribution, composition, structure and functions of plant communities. Transitional zones between biomes, or ecotones, are particularly sensitive to climate change. Ecotones are usually heterogeneous with sparse trees. The dynamics of ecotones are mainly determined by the growth and competition of individual plants in the communities. Therefore it is necessary to calculate the solar radiation absorbed by individual plants in order to understand and predict their responses to climate change. In this study, we developed an individual plant radiation model, IPR (version 1.0), to calculate solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities. The model is developed based on geometrical optical relationships assuming that crowns of woody plants are rectangular boxes with uniform leaf area density. The model calculates the fractions of sunlit and shaded leaf classes and the solar radiation absorbed by each class, including direct radiation from the sun, diffuse radiation from the sky, and scattered radiation from the plant community. The solar radiation received on the ground is also calculated. We tested the model by comparing with the results of random distribution of plants. The tests show that the model results are very close to the averages of the random distributions. This model is efficient in computation, and can be included in vegetation models to simulate long-term transient responses of plant communities to climate change. The code and a user's manual are provided as Supplement of the paper.

Plant development in long-term embryogenic callus lines of Cucurbita pepo

1991 ◽  
Vol 9 (11) ◽  
pp. 623-626 ◽  
Author(s):  
Biserka Juretić ◽  
Sibila Jelaska
Keyword(s):  
Plant Development ◽  
Embryogenic Callus ◽  
Cucurbita Pepo ◽  
Callus Lines

scholarly journals Sunflower cultivation technology with strip tillage in the Ciscaucasian zone

2021 ◽  
pp. 78-80
Author(s):  
Yu. A. Kuzychenko ◽  
R. G. Gadzhiumarov ◽  
A. N. Dzhandarov
Keyword(s):  
Fractal Dimension ◽  
Root System ◽  
Plant Development ◽  
Growing Season ◽  
Climatic Conditions ◽  
Soil Density ◽  
Cultivation System ◽  
Cultivation Technology ◽  
Strip Tillage

The article presents research materials devoted to evaluating the technology of sunflower cultivation with strip basic soil cultivation using elements of Strip-till technology in comparison with the recommended one. The originality of the approach to the cultivation system, in comparison with the classic Strip-till technology, consists in preliminary surface stubble cultivation in two tracks, which retains productive moisture, provokes more intensive germination of weeds, and, accordingly, a more effective effect of subsequent spraying of the stubble with glyphosate. It was found that during the growing season of sunflower with abnormally harsh climatic conditions in 2020 (GTC = 0.07) the soil density in the flowering phase of sunflower was 1.30-1.32 g/cm3, with low moisture reserves in layer 0-100 cm both in spring (57 and 65 mm, respectively) and in bloom (5 and 16 mm, respectively). Applying the fractal dimension method with the calculation of the development index of the root system D, it was found that the harder the agrophysical parameters were during the period of plant development, the less intensively the roots developed: at GTC = 0.22, the D index with the recommended technology and Strip-till technology was 1.63 and 1.76 units respectively, and at GTK = 0.07 — 1.46 and 1.51 units. The low yield of sunflower is associated with a deficit of productive moisture in the summer-autumn period of 2019 and 2020, with a lower reserve of 23 and 102 mm from the long-term norm; nevertheless, a significant increase in the yield of sunflower over the years of research was established by 0.96 and 0.14 tons/ha when cultivating a crop with strip tillage based on the introduction of elements of Strip-till technology in comparison with the recommended one, with a decrease in costs by 11% and an increase in profitability up to 136%.

scholarly journals Exploring the 4D scales of eco-geomorphic interactions along a river corridor using repeat UAV Laser Scanning (UAV-LS), multispectral imagery, and a functional traits framework

2022 ◽  
Author(s):  
Christopher Tomsett ◽  
Julian Leyland
Keyword(s):  
Morphological Change ◽  
Laser Scanning ◽  
Morphological Evolution ◽  
Critical Role ◽  
Individual Plant ◽  
Multispectral Imagery ◽  
Geomorphic Response ◽  
Flow Interactions ◽  
The Individual

Abstract. Vegetation plays a critical role in the modulation of fluvial process and morphological evolution. However, adequately capturing the spatial variability and complexity of vegetation characteristics remains a challenge. Currently, most of the research seeking to address these issues takes place at either the individual plant scale or via larger scale bulk classifications, with the former seeking to characterise vegetation-flow interactions and the latter identifying spatial variation in vegetation types. Herein, we devise a method which extracts functional vegetation traits using UAV laser scanning and multispectral imagery, and upscale these to reach scale guild classifications. Simultaneous monitoring of morphological change is undertaken to identify eco-geomorphic links between different guilds and the geomorphic response of the system in the context of long-term decadal changes. Identification of four guilds from quantitative structural modelling based on analysis of terrestrial and UAV based laser scanning and two further guilds from image analysis was achieved. These were upscaled to reach-scale guild classifications with an overall accuracy of 80 % and links to magnitudes of geomorphic activity explored. We show that different vegetation guilds have a role in influencing morphological change through the stabilisation of banks, but that limits on this influence are evident in the prior long-term analysis. This research reveals that remote sensing offers a solution to the difficulty of scaling traits-based approaches for eco-geomorphic research, and that these methods may be applied to larger areas using airborne laser scanning and satellite imagery datasets.

scholarly journals Long-Term Effects of Cold on Growth, Development and Yield of Narrow-Leaf Lupine May Be Alleviated by Seed Hydropriming or Butenolide

2018 ◽  
Vol 19 (8) ◽  
pp. 2416 ◽  
Author(s):  
Agnieszka Płażek ◽  
Franciszek Dubert ◽  
Przemysław Kopeć ◽  
Michał Dziurka ◽  
Agnieszka Kalandyk ◽  
...  
Keyword(s):  
Low Temperature ◽  
Plant Development ◽  
Long Term Effects ◽  
Vegetative Development ◽  
Germination Ability ◽  
Pre Treatment ◽  
Generative Phase ◽  
Abscisic Acid Content ◽  
Physiological Background

In this article, the effects of cold on the development of Lupine angustifolius and the possibility of mitigating it, via seed hydropriming or pre-treatment with butenolide (10−6 M–10−4 M), are investigated in two cultivars, differing in their ability to germinate at low temperature. Physiological background of plant development after cold stress was investigated in imbibed seeds. For the first four weeks, the seedlings grew at 7 °C or 13 °C. Seeds well germinating at 7 °C demonstrated higher activity of α-amylase and higher levels of gibberellins, IAA and kinetin. Germination ability at low temperature correlated with dehydrogenase activity and membrane permeability. Seed pre-treatment improved germination at low temperature by decreasing abscisic acid content. Seed hydropriming alleviated cold effects on plant development rate and yield, while butenolide accelerated vegetative development but delayed the generative phase. Potential seed yield may be predicted based on the seed germination vigour and the photosynthetic efficiency measured before flowering.

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