scholarly journals Evolutionary transitions between beneficial and phytopathogenic Rhodococcus challenge disease management

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Elizabeth A Savory ◽  
Skylar L Fuller ◽  
Alexandra J Weisberg ◽  
William J Thomas ◽  
Michael I Gordon ◽  
...  
Keyword(s):  
Crop Production ◽  
Production Systems ◽  
Distribution Patterns ◽  
Pathogen Transmission ◽  
Economic Losses ◽  
Virulence Plasmid ◽  
Evolutionary Transitions ◽  
History Of ◽  
Ecological Sampling ◽  
The Impact

Understanding how bacteria affect plant health is crucial for developing sustainable crop production systems. We coupled ecological sampling and genome sequencing to characterize the population genetic history of Rhodococcus and the distribution patterns of virulence plasmids in isolates from nurseries. Analysis of chromosome sequences shows that plants host multiple lineages of Rhodococcus, and suggested that these bacteria are transmitted due to independent introductions, reservoir populations, and point source outbreaks. We demonstrate that isolates lacking virulence genes promote beneficial plant growth, and that the acquisition of a virulence plasmid is sufficient to transition beneficial symbionts to phytopathogens. This evolutionary transition, along with the distribution patterns of plasmids, reveals the impact of horizontal gene transfer in rapidly generating new pathogenic lineages and provides an alternative explanation for pathogen transmission patterns. Results also uncovered a misdiagnosed epidemic that implicated beneficial Rhodococcus bacteria as pathogens of pistachio. The misdiagnosis perpetuated the unnecessary removal of trees and exacerbated economic losses.

Precision Agriculture for Grain Production Systems

2013 ◽  
Author(s):  
Brett Whelan ◽  
James Taylor
Keyword(s):  
Precision Agriculture ◽  
Crop Production ◽  
Engineering Students ◽  
Production Systems ◽  
Management Tool ◽  
Grain Production ◽  
Efficient Manner ◽  
Agricultural Engineering ◽  
Tools And Techniques ◽  
The Impact

Precision Agriculture (PA) is an approach to managing the variability in production agriculture in a more economic and environmentally efficient manner. It has been pioneered as a management tool in the grains industry, and while its development and uptake continues to grow amongst grain farmers worldwide, a broad range of other cropping industries have embraced the concept. This book explains general PA theory, identifies and describes essential tools and techniques, and includes practical examples from the grains industry. Readers will gain an understanding of the magnitude, spatial scale and seasonality of measurable variability in soil attributes, plant growth and environmental conditions. They will be introduced to the role of sensing systems in measuring crop, soil and environment variability, and discover how this variability may have a significant impact on crop production systems. Precision Agriculture for Grain Production Systems will empower crop and soil science students, agronomy and agricultural engineering students, as well as agronomic advisors and farmers to critically analyse the impact of observed variation in resources on crop production and management decisions.

scholarly journals Bacteriophage-Host Association in the Phytoplasma Insect Vector Euscelidius variegatus

Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 612
Author(s):  
Marta Vallino ◽  
Marika Rossi ◽  
Sara Ottati ◽  
Gabriele Martino ◽  
Luciana Galetto ◽  
...  
Keyword(s):  
Crop Production ◽  
Axenic Culture ◽  
Pathogen Transmission ◽  
Economic Losses ◽  
Insect Vector ◽  
Insect Vectors ◽  
Electron Microscopic ◽  
Flavescence Dorée ◽  
Euscelidius Variegatus ◽  
Complex Relationships

Insect vectors transmit viruses and bacteria that can cause severe diseases in plants and economic losses due to a decrease in crop production. Insect vectors, like all other organisms, are colonized by a community of various microorganisms, which can influence their physiology, ecology, evolution, and also their competence as vectors. The important ecological meaning of bacteriophages in various ecosystems and their role in microbial communities has emerged in the past decade. However, only a few phages have been described so far in insect microbiomes. The leafhopper Euscelidius variegatus is a laboratory vector of the phytoplasma causing Flavescence dorée, a severe grapevine disease that threatens viticulture in Europe. Here, the presence of a temperate bacteriophage in E. variegatus (named Euscelidius variegatus phage 1, EVP-1) was revealed through both insect transcriptome analyses and electron microscopic observations. The bacterial host was isolated in axenic culture and identified as the bacterial endosymbiont of E. variegatus (BEV), recently assigned to the genus Candidatus Symbiopectobacterium. BEV harbors multiple prophages that become active in culture, suggesting that different environments can trigger different mechanisms, finely regulating the interactions among phages. Understanding the complex relationships within insect vector microbiomes may help in revealing possible microbe influences on pathogen transmission, and it is a crucial step toward innovative sustainable strategies for disease management in agriculture.

scholarly journals Spatial Characterization of Microbial Communities on Multi-Species Leafy Greens Grown Simultaneously in the Vegetable Production Systems on the International Space Station

Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1060
Author(s):  
Mary E. Hummerick ◽  
Christina L. M. Khodadad ◽  
Anirudha R. Dixit ◽  
Lashelle E. Spencer ◽  
Gretchen J. Maldonado-Vasquez ◽  
...  
Keyword(s):  
International Space Station ◽  
Lactuca Sativa ◽  
Crop Production ◽  
Production Systems ◽  
Space Station ◽  
Amplicon Sequencing ◽  
Vegetable Production ◽  
International Space ◽  
Leafy Greens ◽  
The Impact

The establishment of steady-state continuous crop production during long-term deep space missions is critical for providing consistent nutritional and psychological benefits for the crew, potentially improving their health and performance. Three technology demonstrations were completed achieving simultaneous multi-species plant growth and the concurrent use of two Veggie units on the International Space Station (ISS). Microbiological characterization using molecular and culture-based methods was performed on leaves and roots from two harvests of three leafy greens, red romaine lettuce (Lactuca sativa cv. ‘Outredgeous’); mizuna mustard, (Brassica rapa var japonica); and green leaf lettuce, (Lactuca sativa cv. Waldmann’s) and associated rooting pillow components and Veggie chamber surfaces. Culture based enumeration and pathogen screening indicated the leafy greens were safe for consumption. Surface samples of the Veggie facility and plant pillows revealed low counts of bacteria and fungi and are commonly isolated on ISS. Community analysis was completed with 16S rRNA amplicon sequencing. Comparisons between pillow components, and plant tissue types from VEG-03D, E, and F revealed higher diversity in roots and rooting substrate than the leaves and wick. This work provides valuable information for food production-related research on the ISS and the impact of the plant microbiome on this unique closed environment.

scholarly journals Effect of Colored Shading Nets on the Growth and Water Use Efficiency of Sweet Pepper Grown under Semi-arid Conditions

2022 ◽  
Vol 32 (1) ◽  
pp. 21-27
Author(s):  
Osama Mohawesh ◽  
Ammar Albalasmeh ◽  
Sanjit Deb ◽  
Sukhbir Singh ◽  
Catherine Simpson ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Crop Production ◽  
Production Systems ◽  
Sweet Pepper ◽  
Arid Environments ◽  
Growth Responses ◽  
Use Efficiency ◽  
The Impact ◽  
Semi Arid

Colored shading nets have been increasingly studied in semi-arid crop production systems, primarily because of their ability to reduce solar radiation with the attendant reductions in air, plant, and soil temperatures. However, there is a paucity of research concerning the impact of colored shading nets on various crops grown under semi-arid environments, particularly the sweet pepper (Capsicum annum) production system. This study aimed to investigate the effects of three colored shading net treatments (i.e., white, green, and black shading nets with 50% shading intensity and control with unshaded conditions) on the growth and instantaneous water use efficiency (WUE) of sweet pepper. The results showed that all colored shading nets exhibited significantly lower daytime air temperatures and light intensity (22 to 28 °C and 9992 lx, respectively) compared with the control (32 to 37 °C and 24,973 lx, respectively). There were significant differences in sweet pepper growth performance among treatments, including plant height, shoot dry weight, leaf area, leaf chlorophyll content, and vitamin C in ripened fruit. The enhanced photosynthetic rates were observed in sweet pepper plants under the colored shading nets compared with control plants. WUE increased among the colored shading net treatments in the following order: control ≤ white < black < green. Overall, the application of green and black shading nets to sweet pepper production systems under semi-arid environments significantly enhanced plant growth responses and WUE.

An Impact of Innovations on Agricultural Production and Malong the Koshi-Highway of Eastern Nepal

2020 ◽  
Vol 4 (1) ◽  
pp. 164-175
Author(s):  
Shyam Prasad Wagle
Keyword(s):  
Agricultural Production ◽  
Crop Production ◽  
New Technologies ◽  
Production Systems ◽  
Secondary Data ◽  
Primary Data ◽  
Innovative Methods ◽  
Wide Range ◽  
The Government ◽  
The Impact

 The study assesses the impact of using new technologies on crop production and marketing of selected crops particularly in the case of the Eastern hills. It also evaluates the role of governmental and non-govrnmental organizations to improve agricultural production systems too. Relevant data have been collected from both primary and secondary sources. Primary data draws from the interview, key informant survey and field observation. For this, 30 percent sample households were selected from three altitude belts (upper, middle and lower belts) ranging from 300 to 2,250 masl along the Koshi-highway. It has a wide range of climates, ranging from sub-tropical to alpine with monsoon precipitation in the summer for three and half months and therefore it has diversity in flora and fauna, and people. Similarly, secondary data havebeen gathered from various books, journals and official records. This paper presented that the crucial impact of acceptance of innovative methods in agriculture in the study area is a combined effort of both local people and government. The government together with the development agencies and non-government organizations has contributed to impart knowledge of the agriculture innovative methods in the local farmers and at the same time, the farmers were enthusiastic to learn and adopt those methods. As a result, one can easily see the remarkable changes in crop production due to the impact of new technologies.

Out of Amazonia and Back Again: Historical Biogeography of the Species-Rich Neotropical Genus Philodendron (Araceae)

2019 ◽  
Vol 104 (1) ◽  
pp. 49-68 ◽  
Author(s):  
Dubán Canal ◽  
Nils Köster ◽  
Marcela Celis ◽  
Thomas B. Croat ◽  
Thomas Borsch ◽  
...  
Keyword(s):  
Species Diversity ◽  
Distribution Patterns ◽  
Geographic Range ◽  
Northern Andes ◽  
Caribbean Islands ◽  
The Andes ◽  
Isthmus Of Panama ◽  
History Of ◽  
Andean Uplift ◽  
The Impact

The origin of Neotropical species diversity is strongly associated with the geological history of South America. Since the Miocene, a number of species radiations across different Neotropical lineages coincided with the rise of the Andes and the formation of the Isthmus of Panama. The species-rich genus Philodendron Schott (Araceae) is widely distributed across Neotropical rainforests, originating in the Late Oligocene and diversifying more intensely from the Miocene onward. It is likely that its diversification process and distribution patterns are associated with recent geological changes in the Americas. To test this hypothesis, we sampled the species diversity of Philodendron across its entire geographic range and used a combination of three non-coding plastid regions (petD, rpl16, and trnK/matK) to obtain a comprehensive time-calibrated phylogeny. We then inferred geographic range evolution and explored the impact of the Andean orogeny on speciation, extinction, and dispersal. The genus Philodendron originated ~29 million years ago (mya) and experienced the earliest diversification events ~25 mya in the Pan-Amazonian rainforests. From the Middle Miocene onward, multiple geographic range expansion events occurred from Amazonia to southeast Brazil and to the area which would become the Chocó and the northern Andes. From the Pliocene onward, Philodendron reached Central America and the Caribbean islands, and Andean lineages recolonized and diversified in Amazonia. In Philodendron, higher diversification rates are found in the adjacent lowland rainforests of the northern Andes compared with other regions in the Neotropics, demonstrating a potential indirect impact of the Andean uplift on species radiations in lowland regions.

scholarly journals Demographic history and admixture dynamics in African Sahelian populations

2020 ◽  
Author(s):  
Viktor Černý ◽  
Cesar Fortes-Lima ◽  
Petr Tříska
Keyword(s):  
Demographic History ◽  
Distribution Patterns ◽  
Human Populations ◽  
African Region ◽  
Genetic Studies ◽  
Genomic Studies ◽  
History Of ◽  
Sub Saharan ◽  
High Degree ◽  
The Impact

Abstract The Sahel/Savannah belt of Africa is a contact zone between two subsistence systems (nomadic pastoralism and sedentary farming) and of two groups of populations, namely Eurasians penetrating from northern Africa southwards and sub-Saharan Africans migrating northwards. Because pastoralism is characterised by a high degree of mobility, it leaves few significant archaeological traces. Demographic history seen through the lens of population genetic studies complements our historical and archaeological knowledge in this African region. In this review, we highlight recent advances in our understanding of demographic history in the Sahel/Savannah belt as revealed by genetic studies. We show the impact of food-producing subsistence strategies on population structure as well as the somewhat different migration patterns in the western and eastern part of the region. Genomic studies show that the gene pool of various groups of Sahelians consists in a complex mosaic of several ancestries. We also touch upon various signals of genetic adaptations such as lactase persistence, taste sensitivity, and malaria resistance, all of which have different distribution patterns among Sahelian populations. Overall, genetic studies contribute to gain a deeper understanding about the demographic and adaptive history of human populations in this specific African region and beyond.

scholarly journals Focus Issue Articles on Emerging and Re-Emerging Plant Diseases

2015 ◽  
Vol 105 (7) ◽  
pp. 852-854 ◽  
Author(s):  
Krishna V. Subbarao ◽  
George W. Sundin ◽  
Steven J. Klosterman
Keyword(s):  
Crop Production ◽  
Plant Pathogens ◽  
Local Level ◽  
Emerging Diseases ◽  
Human Migration ◽  
Plant Diseases ◽  
Modern Agriculture ◽  
History Of ◽  
Agriculture And Food ◽  
The Impact

The history of plant pathology is closely tied to plant diseases that have changed the course of human history. The Irish potato famine, caused by late blight of potato, resulted in the starvation and death of millions of people and one of the most influential human migrations in history. Other plant diseases have impacted quality of life in myriad ways. The advent of fungicides, clean seeds, host resistance, and the development of a plethora of other techniques, has diminished the impact of plant diseases. However, impressive advances in modes of rapid transport have not only increased global trade and human migration, but also augmented the risk for anthropogenic invasions of plant pathogens. As a consequence, and possibly aggravated by climate change, many historical and contemporary diseases are emerging as threats to modern agriculture and food security. These emerging diseases are not only important in global crop production, but also pose severe risks on a local level, especially on small farms in developing countries. This Focus Issue of Phytopathology contains a collection of peer-reviewed research articles, invited reviews and perspective articles on an assortment of emerging and re-emerging diseases caused by bacterial (3 papers), fungal (6 papers), oomycete (5 papers), and viral plant pathogens (3 papers). These diseases cover a range of crops including annual field crops and perennial tree crops, and vegetables, across five continents.

scholarly journals Herbicide Resistance: Toward an Understanding of Resistance Development and the Impact of Herbicide-Resistant Crops

Weed Science ◽  
2012 ◽  
Vol 60 (SP1) ◽  
pp. 2-30 ◽  
Author(s):  
William K. Vencill ◽  
Robert L. Nichols ◽  
Theodore M. Webster ◽  
John K. Soteres ◽  
Carol Mallory-Smith ◽  
...  
Keyword(s):  
Crop Production ◽  
Cultural Practices ◽  
Production Systems ◽  
Mechanisms Of Action ◽  
Slight Reduction ◽  
Herbicide Resistant ◽  
Concurrent Use ◽  
High Selection ◽  
Herbicide Use ◽  
The Impact

Development of herbicide-resistant crops has resulted in significant changes to agronomic practices, one of which is the adoption of effective, simple, low-risk, crop-production systems with less dependency on tillage and lower energy requirements. Overall, the changes have had a positive environmental effect by reducing soil erosion, the fuel use for tillage, and the number of herbicides with groundwater advisories as well as a slight reduction in the overall environmental impact quotient of herbicide use. However, herbicides exert a high selection pressure on weed populations, and density and diversity of weed communities change over time in response to herbicides and other control practices imposed on them. Repeated and intensive use of herbicides with the same mechanisms of action (MOA; the mechanism in the plant that the herbicide detrimentally affects so that the plant succumbs to the herbicide; e.g., inhibition of an enzyme that is vital to plant growth or the inability of a plant to metabolize the herbicide before it has done damage) can rapidly select for shifts to tolerant, difficult-to-control weeds and the evolution of herbicide-resistant weeds, especially in the absence of the concurrent use of herbicides with different mechanisms of action or the use of mechanical or cultural practices or both.

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