scholarly journals Water deficiency at different developmental stages of Glycine max can improve drought tolerance

Bragantia ◽  
2008 ◽  
Vol 67 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Alan Panaia Kron ◽  
Gustavo Maia Souza ◽  
Rafael Vasconcelos Ribeiro
Keyword(s):  
Water Deficit ◽  
Plant Development ◽  
Energy Use ◽  
Developmental Stages ◽  
Water Shortage ◽  
Energetic Cost ◽  
Conservative Strategy ◽  
Environmental Perturbations ◽  
Soybean Plants ◽  
The One

Developmental windows are specific periods of sensitivity during normal plant development in which a perturbation may be adaptively integrated. In these periods, sub-lethal environmental perturbations may improve the capacity to grow at lethal conditions. The aim of this study was to test the hypothesis that previous non-lethal water deficit applied in different developmental stages in soybean plants could enables them to improve the tolerance to environmental perturbations. In order to test this hypothesis we carried out an experiment with soybean plants submitted to water deficit in different stages of plant development, evaluating yield and physiological aspects. Our results indicated that water deficit experienced on V4 stage (vegetative) induces more suitable response, enabling plants to develop a process of tolerance improvement to a further water shortage period, probably through a reduction of growth, which maintains a conservative strategy of energy use. On the other hand, water deficit in R1 stage (reproductive), increased the plant susceptibility to posterior water withholding. This " strategy" was the opposite of the one employed by plants on V4 stage, i.e., to maintain growth rate probably at the expense of a higher energetic cost.

scholarly journals Limitations imposed by wearing armour on Medieval soldiers' locomotor performance

2011 ◽  
Vol 279 (1729) ◽  
pp. 640-644 ◽  
Author(s):  
Graham N. Askew ◽  
Federico Formenti ◽  
Alberto E. Minetti
Keyword(s):  
Fifteenth Century ◽  
Physical Performance ◽  
Energy Use ◽  
Steel Plate ◽  
Energetic Cost ◽  
Entire Body ◽  
Additional Mass ◽  
Medieval Europe ◽  
Cost Of Locomotion ◽  
Locomotor Energetics

In Medieval Europe, soldiers wore steel plate armour for protection during warfare. Armour design reflected a trade-off between protection and mobility it offered the wearer. By the fifteenth century, a typical suit of field armour weighed between 30 and 50 kg and was distributed over the entire body. How much wearing armour affected Medieval soldiers' locomotor energetics and biomechanics is unknown. We investigated the mechanics and the energetic cost of locomotion in armour, and determined the effects on physical performance. We found that the net cost of locomotion ( C met ) during armoured walking and running is much more energetically expensive than unloaded locomotion. C met for locomotion in armour was 2.1–2.3 times higher for walking, and 1.9 times higher for running when compared with C met for unloaded locomotion at the same speed. An important component of the increased energy use results from the extra force that must be generated to support the additional mass. However, the energetic cost of locomotion in armour was also much higher than equivalent trunk loading. This additional cost is mostly explained by the increased energy required to swing the limbs and impaired breathing. Our findings can predict age-associated decline in Medieval soldiers' physical performance, and have potential implications in understanding the outcomes of past European military battles.

Observing microscopic phases of lichen life cycles on transparent substrata placed in situ

2005 ◽  
Vol 37 (5) ◽  
pp. 373-382 ◽  
Author(s):  
William B. SANDERS
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Life Cycles ◽  
Potential Significance ◽  
Free Living ◽  
Lichen Community ◽  
One Year ◽  
The One ◽  
Observation Period

The utility of plastic cover slips as a substratum for in situ study of lichen developmental stages is further explored in a neotropical foliicolous lichen community and in a European temperate corticolous community. Twenty-one months after placement in the tropical forest, the cover slips bore foliicolous lichen thalli with several species producing characteristic ascocarps and ascospores, indicating the suitability of the substratum for completion of the life cycle of these lichens. On cover slips placed within the temperate corticolous community, lichen propagules anchored to the substratum with relatively short attachment hyphae but did not develop further within the one year observation period. Intimately intermixed microbial communities of short-celled, mainly pigmented fungi and chlorophyte algae developed upon the transparent substratum. Among the algae, Trebouxia cells, often in groups showing cell division and without associated lichenizing hyphae, were commonly observed. The potential significance of the free-living populations in the life cycle of Trebouxia and in those of Trebouxia-associated lichen fungi is discussed.

scholarly journals Co-inoculation with Azospirillum brasilense in soybean cultivars subjected to water déficit

2020 ◽  
Vol 24 (2) ◽  
pp. 89-94 ◽  
Author(s):  
Alessandra M. de L. Naoe ◽  
Joênes M. Peluzio ◽  
Leonardo J. M. Campos ◽  
Lucas K. Naoe ◽  
Roberta A. e Silva
Keyword(s):  
Grain Yield ◽  
Water Deficit ◽  
Bradyrhizobium Japonicum ◽  
Azospirillum Brasilense ◽  
Field Experiments ◽  
Crop Evapotranspiration ◽  
Plant Genotype ◽  
Soybean Cultivars ◽  
Sowing Dates ◽  
Soybean Plants

ABSTRACT This study aimed to verify the effect of co-inoculation, association between Azospirillum brasilense and Bradyrhizobium japonicum bacteria, on soybean plants subjected to water deficit at two sowing dates. Two field experiments were conducted at the Universidade Federal de Tocantins, campus of Palmas, Brazil, in 2016. The experimental design was randomized blocks in a split-split-plot arrangement with four repetitions, where the plots consisted of two irrigation depths (100 and 25% of crop evapotranspiration - ETc), the subplots was composed of two methods of inoculant application (inoculation with Bradyrhizobium japonicum and co-inoculation with Azospirillum brasilense + Bradyrhizobium japonicum) and the sub-subplots comprised two soybean cultivars (TMG 132 and ANTA 82). The cultivars responded differently to the sowing dates. Co-inoculation did not influence grain yield under full irrigation conditions (100% ETc), in neither cultivar evaluated. However, under the water deficit condition (25% ETc), the grain yield of the cultivar TMG 132 increased 77.20%, indicating that there are different responses of interaction between Azospirillum brasilense, plant genotype and sowing dates.

scholarly journals Plant Developmental Stage Drives the Differentiation in Ecological Role of Plant Bacterial and Fungal Microbiomes

2021 ◽  
Author(s):  
Chao Xiong ◽  
Brajesh K. Singh ◽  
Ji-Zheng He ◽  
Yan-Lai Han ◽  
Pei-Pei Li ◽  
...  
Keyword(s):  
Developmental Stage ◽  
Plant Development ◽  
Late Stage ◽  
Developmental Stages ◽  
Early Stage ◽  
Alpha Diversity ◽  
Microbial Interactions ◽  
Disease Suppression ◽  
Fungal Communities ◽  
Ecological Role

Abstract BackgroundPlants live with diverse microbial communities which profoundly affect multiple facets of host performance such as nutrition acquisition, disease suppression and productivity, but if and how host development impacts the assembly, functions and microbial interactions of crop microbiomes are poorly understood. Here we examined both bacterial and fungal communities across soils (rhizosphere and bulk soil), plant epiphytic and endophytic niches (phylloplane, rhizoplane, leaf and root endosphere), and plastic leaf of fake plant (representing environment-originating microbes) at three developmental stages of maize at two contrasting sites, and further explored the potential function of phylloplane microbiomes based on metagenomics.ResultsOur results suggested that plant developmental stage had a much stronger influence on the microbial diversity, composition and interkingdom networks in plant compartment niches than in soils, with the strongest effect in the phylloplane. Air (represented by fake plants) was an important source of phylloplane microbiomes which were co-shaped by both plant development and seasonal environmental factors. Further, we demonstrated that bacterial and fungal communities in plant compartment niches exhibited contrasting response to host developmental stages, with higher alpha diversity and stronger deterministic assembly within bacterial microbiomes at the early stage but a similar pattern within mycobiomes at the late stage. Moreover, we found that bacterial taxa played a more important role in microbial interkingdom network and crop yield prediction at the early stage, while fungal taxa did so at the late stage. Metagenomic analyses further indicated that phylloplane microbiomes possessed higher functional diversity and functional genes involved in nutrient provision and disease resistance at the early stage than the late stage. ConclusionsOur results suggest that host developmental stage profoundly influences plant microbiome assembly and functions, and the bacterial and fungal microbiomes take a differentiated ecological role at different plant development stages. This study provides empirical evidence for host exerting strong effect on plant microbiomes by deterministic selection to meet the physiological requirement of plant developmental stages. These findings have implications for the development of future tools to manipulate microbiome for sustainable increase in primary productivity.

Whirling Disease: Reviews and Current Topics

2002 ◽  
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Small Subunit ◽  
Fish Host ◽  
Complex Life Cycle ◽  
Developmental Cycle ◽  
Myxobolus Cerebralis ◽  
Rdna Sequences ◽  
Complex Development ◽  
The One

<em>ABSTRACT. Myxobolus cerebralis </em>possesses unique phenotypic and genotypic characteristics when compared with other histozoic parasites from the phylum Myxozoa. The parasite infects the cartilage and thereby induces a serious and potentially lethal disease in salmonid fish. Comparisons of the small subunit ribosomal DNA (ssu rDNA) sequences of <em>M. cerebralis </em>to other myxozoans demonstrate that the parasite has evolved separately from other <em>Myxobolus </em>spp. that may appear in cartilage or nervous tissues of the fish host. <em>Myxobolus cerebralis </em>has a complex life cycle involving two hosts and numerous developmental stages that may divide by mitosis, endogeny, or plasmotomy, and, at one stage, by meiosis. In the salmonid host, the parasite undergoes extensive migration from initial sites of attachment to the epidermis, through the nervous system, to reach cartilage, the site where sporogenesis occurs. During this migration, parasite numbers may increase by replication. Sporogenesis is initiated by autogamy, a process typical of pansporoblastic myxosporean development that involves the union of the one cell (pericyte) with another (sporogonic). Following this union, the sporogonic cell will give rise to all subsequent cells that differentiate into the lenticular shaped spore with a diameter of approximately 10 µm. This spore or myxospore is an environmentally resistant stage characterized by two hardened valves surrounding two polar capsules with coiled filaments and a binucleate sporoplasm cell. In the fish, these spores are found only in cartilage where they reside until released from fish that die or are consumed by other fish or fish-eating animals (e.g., birds). Spores reaching the aquatic sediments can be ingested and hatch in susceptible oligochaete hosts. The released sporoplasm invades and then resides between cells of the intestinal mucosa. In contrast to the parasite in the fish host, the parasite in the oligochaete undergoes the entire developmental cycle in this location. This developmental cycle involves merogony, gametogamy or the formation of haploid gametes, and sporogony. The actinosporean spores, formed at the culmination of this development, are released into the lumen of the intestine, prior to discharging into the aquatic environment. The mechanisms underlying the complex development of <em>M. cerebralis</em>, and its interactions with both hosts, are poorly understood. Recent advances, however, are providing insights into the factors that mediate certain phases of the infection. In this review, we consider known and recently obtained information on the taxonomy, development, and life cycle of the parasite.

scholarly journals Automated Measurement and Control of Germination Paper Water Content

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2232
Author(s):  
Lina Owino ◽  
Marvin Hilkens ◽  
Friederike Kögler ◽  
Dirk Söffker
Keyword(s):  
Water Content ◽  
Water Deficit ◽  
Plant Development ◽  
Growth Substrate ◽  
Irrigation Amount ◽  
Control Approach ◽  
Predictive Controller ◽  
And Control ◽  
Improved Accuracy ◽  
Measurement And Control

Germination paper (GP) is used as a growth substrate in plant development studies. Current studies bear two limitations: (1) The actual GP water content and variations in GP water content are neglected. (2) Existing irrigation methods either maintain the GP water content at fully sufficient or at a constant deficit. Variation of the intensity of water deficit over time for plants grown on GP is not directly achievable using these methods. In this contribution, a new measurement and control approach was presented. As a first step, a more precise measurement of water content was realized by employing the discharging process of capacitors to determine the electrical resistance of GP, which is related to the water content. A Kalman filter using an evapotranspiration model in combination with experimental data was used to refine the measurements, serving as the input for a model predictive controller (MPC). The MPC was used to improve the dynamics of the irrigation amount to more precisely achieve the required water content for regulated water uptake in plant studies. This is important in studies involving deficit irrigation. The novel method described was capable of increasing the accuracy of GP water content control. As a first step, the measurement system achieved an improved accuracy of 0.22 g/g. The application of a MPC for water content control based on the improved measurement results in an overall control accuracy was 0.09 g/g. This method offers a new approach, allowing the use of GP for studies with varying water content. This addressed the limitations of existing plant growth studies and allowed the prospection of dependencies between dynamic water deficit and plant development using GP as a growth substrate for research studies.

scholarly journals Different soaking times and niacin concentrations affect yield of upland rice under water deficit conditions

2019 ◽  
Vol 37 (2) ◽  
pp. 166-172
Author(s):  
Eduardo Pradi Vendruscolo ◽  
Aliny Heloísa Alcântara Rodrigues ◽  
Sávio Rosa Correa ◽  
Alexander Seleguini ◽  
Sebastião Ferreira de Lima
Keyword(s):  
Grain Yield ◽  
Water Deficit ◽  
Plant Development ◽  
Maximum Concentration ◽  
Upland Rice ◽  
Seedling Emergence ◽  
Rice Seed ◽  
Relative Index ◽  
Spikelets Per Panicle ◽  
Production Characteristics

Rice is an important source of energy for a large part of the world’s population. The development and application of technologies that contribute to the improvement of production forthis grain have great importance. The objective of this study was to evaluate the influence of rice seed immersion in a niacin solution on plant development, physiology and production. Thetreatments were defined by a combination of two immersion times for the seeds (12 h and 24 h) in four niacin concentrations (0.00, 100, 200 and 300 mg L-1) distributed in five replicates. Characteristics relating to seedling emergence, plant vegetativedevelopment, relative indices of chlorophyll and grain yield were evaluated. We verified that the immersion of the seeds for 12 h gave higher relative indices of chlorophyll, whereas immersion for 24 h increased the speed of emergence and the number of tillers and panicles. The doses of niacin positively affected the relative chlorophyll indices and the production characteristics, up to a maximum concentration of 172.57 mg L-1. We concluded that the immersion of rice seeds for 24 h increased the speed of seedling emergence, leaf number, and panicles per area. However, the relative indices of chlorophyll in leaves decreased. The use of niacin promoted the numbers of spikelets per panicle, fertility of the spikelets and the weight of 1000 grains, besides increasing the relative index of chlorophyll in the leaves of rice plants.

Phenology, leaf gas exchange, growth, and seed yield in contrasting Medicago truncatula and Medicago laciniata populations during prolonged water deficit and recovery

Botany ◽  
2012 ◽  
Vol 90 (2) ◽  
pp. 79-91 ◽  
Author(s):  
Nasreddine Yousfi ◽  
Ines Slama ◽  
Chedly Abdelly
Keyword(s):  
Water Deficit ◽  
Medicago Truncatula ◽  
Seed Yield ◽  
Growth Parameters ◽  
Leaf Gas Exchange ◽  
Seed Mass ◽  
Field Capacity ◽  
Water Shortage ◽  
Relative Water ◽  
Leaf Relative Water Content

The aims of this study were to investigate the effect of prolonged water stress and recovery on phenology, growth, and seed yield in Tunisian contrasting populations of Medicago truncatula and Medicago laciniata . After ample irrigation for 24 days, the plants of each population were divided into two lots: the first lot was irrigated at 100% field capacity (FC), and the second at only 45% FC. After 24 days of treatment, one lot of dehydrated plants was rewatered at 100% FC, while the other was maintained at 45% FC. Interspecific and intraspecific differences were found in phenological responses to water deficit. All growth parameters were more reduced in M. truncatula populations than in M. laciniata populations. The water shortage tolerance of M. laciniata populations was associated with a lower metabolic impairment of photosynthesis and maintenance of relatively higher leaf relative water content. Seed yield was also more reduced in M. truncatula populations compared with M. laciniata populations. In M. laciniata, seed mass was a compensation mechanism to sustain seed yield under drought conditions. Seed yield variation between populations under water deficit was explained mainly by variation in seed number per plant.

scholarly journals Characteristics of agro and wood biomass combustion in the stream of inert material

2019 ◽  
Vol 137 ◽  
pp. 01031
Author(s):  
Konrad Kaczyński ◽  
Katarzyna Kaczyńska ◽  
Piotr Pełka
Keyword(s):  
Energy Use ◽  
Operating Conditions ◽  
Biomass Combustion ◽  
Inert Material ◽  
Wood Biomass ◽  
Wood Pellets ◽  
Residual Biomass ◽  
The World ◽  
Laboratory Reactor ◽  
The One

Agricultural residual biomass presents a high potential for energy use around the world, often not utilized to a large extent due to its significant differences with respect to other biomass types, such as the one of wood origin. These differences are mainly related to the characteristics of its ashes (quantity and composition) which increase certain problematic phenomena during combustion, among them ash sintering. The main purpose of this article is the experimental study of these issues for various agro pellets and wood pellets, analyzed in various operating conditions in a laboratory reactor with a circulating bed.

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