Forest Conservation Genetics

2000 ◽  
Author(s):  
Andrew Young ◽  
David Boshier ◽  
Timothy Boyle
Keyword(s):  
Genetic Diversity ◽  
Conservation Genetics ◽  
Undergraduate Students ◽  
Sustainable Management ◽  
Forest Conservation ◽  
Production Systems ◽  
Management Strategies ◽  
Management Policy ◽  
Tropical Regions ◽  
Logical Sequence

Forest management must be sustainable not only in ecological, economic and social, but also genetic terms. Many forest managers are advocating and developing management strategies that give priority to conserving genetic diversity within production systems, or that recognise the importance of genetic considerations in achieving sustainable management. Forest Conservation Genetics draws together much previously uncollected information relevant to managing and conserving forests. The content emphasises the importance of conserving genetic diversity in achieving sustainable management. Each chapter is written by a leading expert and has been peer reviewed. Readers without a background in genetics will find the logical sequence of topics allows easy understanding of the principles involved and how those principles may impact on day-to-day forest planning and management decisions. The book is primarily aimed at undergraduate students of biology, ecology, forestry, and graduate students of forest genetics, resource management policy and/or conservation biology. It will prove useful for those teaching courses in these fields and as such help to increase the awareness of genetic factors in conservation and sustainable management, in both temperate and tropical regions.

scholarly journals Legumes increase grassland productivity with no effect on nitrous oxide emissions

2019 ◽  
Vol 446 (1-2) ◽  
pp. 163-177 ◽  
Author(s):  
Arlete S. Barneze ◽  
Jeanette Whitaker ◽  
Niall P. McNamara ◽  
Nicholas J. Ostle
Keyword(s):  
Management Practices ◽  
Production Systems ◽  
N Uptake ◽  
Relative Proportion ◽  
Management Strategies ◽  
Ghg Emissions ◽  
Chemical Properties ◽  
Nitrous Oxide Emissions ◽  
Mineral N ◽  
Grassland Productivity

Abstract Aims Grasslands are important agricultural production systems, where ecosystem functioning is affected by land management practices. Grass-legume mixtures are commonly cultivated to increase grassland productivity while reducing the need for nitrogen (N) fertiliser. However, little is known about the effect of this increase in productivity on greenhouse gas (GHG) emissions in grass-legume mixtures. The aim of this study was to investigate interactions between the proportion of legumes in grass-legume mixtures and N-fertiliser addition on productivity and GHG emissions. We tested the hypotheses that an increase in the relative proportion of legumes would increase plant productivity and decrease GHG emissions, and the magnitude of these effects would be reduced by N-fertiliser addition. Methods This was tested in a controlled environment mesocosm experiment with one grass and one legume species grown in mixtures in different proportions, with or without N-fertiliser. The effects on N cycling processes were assessed by measurement of above- and below-ground biomass, shoot N uptake, soil physico-chemical properties and GHG emissions. Results Above-ground productivity and shoot N uptake were greater in legume-grass mixtures compared to grass or legume monocultures, in fertilised and unfertilised soils. However, we found no effect of legume proportion on N2O emissions, total soil N or mineral-N in fertilised or unfertilised soils. Conclusions This study shows that the inclusion of legumes in grass-legume mixtures positively affected productivity, however N cycle were in the short-term unaffected and mainly affected by nitrogen fertilisation. Legumes can be used in grassland management strategies to mitigate climate change by reducing crop demand for N-fertilisers.

scholarly journals Mitogenomic analysis of diversity of key whitefly pests in Kenya and its implication to their sustainable management

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fathiya M. Khamis ◽  
Fidelis L. O. Ombura ◽  
Inusa J. Ajene ◽  
Komivi S. Akutse ◽  
Sevgan Subramanian ◽  
...  
Keyword(s):  
Sustainable Management ◽  
Management Strategies ◽  
Spatial Models ◽  
Abundant Species ◽  
Plant Viruses ◽  
Pest Species ◽  
Agricultural Pests ◽  
Protein Coding ◽  
Aleyrodes Proletella ◽  
Aleurodicus Dispersus

AbstractWhiteflies (Hemiptera: Aleyrodidae) are devastating agricultural pests of economic importance vectoring pathogenic plant viruses. Knowledge on their diversity and distribution in Kenya is scanty, limiting development of effective sustainable management strategies. The present study is aimed at identifying whitefly pest species present in Kenya across different agroecological zones and establish predictive models for the most abundant species in Africa. Whiteflies were sampled in Kenya from key crops known to be severely infested and identified using 16S rRNA markers and complete mitochondrial genomes. Four whitefly species were identified: Aleyrodes proletella, Aleurodicus dispersus, Bemisia afer and Trialeurodesvaporariorum, the latter being the most dominant species across all the agroecology. The assembly of complete mitogenomes and comparative analysis of all 13 protein coding genes confirmed the identities of the four species. Furthermore, prediction spatial models indicated high climatic suitability of T. vaporariorum in Africa, Europe, Central America, parts of Southern America, parts of Australia, New Zealand and Asia. Consequently, our findings provide information to guide biosecurity agencies on protocols to be adopted for precise identification of pest whitefly species in Kenya to serve as an early warning tool against T. vaporariorum invasion into unaffected areas and guide appropriate decision-making on their management.

Distribution, abundance and natural enemies of the invasive tomato leafminer, Tuta absoluta (Meyrick) in Kenya

2021 ◽  
pp. 1-16
Author(s):  
G. Kinyanjui ◽  
F. M. Khamis ◽  
F. L. O. Ombura ◽  
E. U. Kenya ◽  
S. Ekesi ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Sustainable Management ◽  
Management Strategies ◽  
Tuta Absoluta ◽  
Macrolophus Pygmaeus ◽  
Larval Parasitoids ◽  
Parasitism Rates ◽  
Nesidiocoris Tenuis ◽  
Sentinel Plants ◽  
Open Fields

Abstract Tuta absoluta (Meyrick) has become a serious menace to sustainable production of tomato in Kenya. A survey was conducted between April 2015 and June 2016 to determine its distribution, abundance, infestation, and damage levels on tomato, and associated natural enemies. Trap counts of T. absoluta moths were recorded in all surveyed 29 counties, which indicated its nationwide distribution irrespective of altitude. Tuta absoluta was present in both open fields and greenhouses. The highest moth/trap/day was 115.38 ± 15.90. Highest leaf infestation was 92.22% and the highest number of mines and larvae per leaf were 3.71 ± 0.28 and 2.16 ± 0.45, respectively. Trap captures in terms of moth/trap/day were linearly and positively related to leaf infestations in open fields (R2 = 0.81) and greenhouses (R2 = 0.61). Highest fruits’ infestation and damage were 60.00 and 59.61%, respectively, while the highest number of mines per fruit was 7.50 ± 0.50. Nesidiocoris tenuis (Reuter) and Macrolophus pygmaeus (Rambur) were identified as predators of T. absoluta larvae. Nine species of larval parasitoids were recovered from infested foliage, with a combined parasitism of 7.26 ± 0.65%. Hockeria species was the most dominant (31.25%) and accounted for 12.88 ± 1.47% parasitism. Two species of larval parasitoids, Hockeria and Necremnus were obtained from sentinel plants with an average parasitism of 1.13 ± 0.25. The overall abundance and parasitism rates of recovered natural enemies were low to effectively control the field populations of T. absoluta. These findings form the basis of researching and developing effective and sustainable management strategies for the pest.

scholarly journals Metagenomic analyses and genetic diversity of Tomato leaf curl Arusha virus affecting tomato plants in Kenya

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Edith Khamonya Avedi ◽  
Adedapo Olutola Adediji ◽  
Dora Chao Kilalo ◽  
Florence Mmogi Olubayo ◽  
Isaac Macharia ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Selection Pressure ◽  
Management Strategies ◽  
Purifying Selection ◽  
Tomato Leaf ◽  
Amino Acid Sequences ◽  
Virus Population ◽  
Tomato Production ◽  
Tomato Leaf Curl ◽  
Leaf Curl

Abstract Background Tomato production is threatened worldwide by the occurrence of begomoviruses which are associated with tomato leaf curl diseases. There is little information on the molecular properties of tomato begomoviruses in Kenya, hence we investigated the population and genetic diversity of begomoviruses associated with tomato leaf curl in Kenya. Methods Tomato leaf samples with virus-like symptoms were obtained from farmers’ field across the country in 2018 and Illumina sequencing undertaken to determine the genetic diversity of associated begomoviruses. Additionally, the occurrence of selection pressure and recombinant isolates within the population were also evaluated. Results Twelve complete begomovirus genomes were obtained from our samples with an average coverage of 99.9%. The sequences showed 95.7–99.7% identity among each other and 95.9–98.9% similarities with a Tomato leaf curl virus Arusha virus (ToLCArV) isolate from Tanzania. Analysis of amino acid sequences showed the highest identities in the regions coding for the coat protein gene (98.5–100%) within the isolates, and 97.1–100% identity with the C4 gene of ToLCArV. Phylogenetic algorithms clustered all Kenyan isolates in the same clades with ToLCArV, thus confirming the isolates to be a variant of the virus. There was no evidence of recombination within our isolates. Estimation of selection pressure within the virus population revealed the occurrence of negative or purifying selection in five out of the six coding regions of the sequences. Conclusions The begomovirus associated with tomato leaf curl diseases of tomato in Kenya is a variant of ToLCArV, possibly originating from Tanzania. There is low genetic diversity within the virus population and this information is useful in the development of appropriate management strategies for the disease in the country.

scholarly journals Molecular detection and genetic diversity of Leucocytozoon sabrazesi in chickens in Thailand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Runglawan Chawengkirttikul ◽  
Witchuta Junsiri ◽  
Amaya Watthanadirek ◽  
Napassorn Poolsawat ◽  
Sutthida Minsakorn ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Egg Production ◽  
Control Strategies ◽  
Amino Acid Sequences ◽  
Economic Losses ◽  
Nested Polymerase Chain Reaction ◽  
Blood Samples ◽  
Tropical Regions ◽  
Vaccination Programs ◽  
High Entropy

AbstractLeucocytozoon sabrazesi is the intracellular protozoa of leucocytozoonosis, which is transmitted by the insect vectors and affects chickens in most subtropical and tropical regions of the globe, except South America, and causing enormous economic losses due to decreasing meat yield and egg production. In this study, L. sabrazesi gametocytes have been observed in the blood smears, and molecular methods have been used to analyse the occurrence and genetic diversity of L. sabrazesi in blood samples from 313 chickens raised in northern, western and southern parts of Thailand. The nested polymerase chain reaction (nested PCR) assay based on the cytb gene revealed that 80.51% (252/313) chickens were positive of L. sabrazesi. The phylogenetic analysis indicated that L. sabrazesi cytb gene is conserved in Thailand, showed 2 clades and 2 subclades with similarity ranged from 89.5 to 100%. The diversity analysis showed 13 and 18 haplotypes of the sequences from Thailand and from other countries, respectively. The entropy analyses of nucleic acid sequences showed 26 high entropy peaks with values ranging from 0.24493 to 1.21056, while those of amino acid sequences exhibited 5 high entropy peaks with values ranging from 0.39267 to 0.97012. The results; therefore, indicate a high molecular occurrence of L. sabrazesi in chicken blood samples with the associated factors that is statistically significant (p < 0.05). Hence, our results could be used to improve the immunodiagnostic methods and to find appropriate preventive control strategies or vaccination programs against leucocytozoonosis in order to mitigate or eliminate the harmful impact of this infection on chicken industry.

scholarly journals Mitochondrial Genetic Diversity among Farmed Stocks of Oreochromis spp. (Perciformes, Cichlidae) in Madagascar

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 281
Author(s):  
Nicolas Hubert ◽  
Elodie Pepey ◽  
Jean-Michel Mortillaro ◽  
Dirk Steinke ◽  
Diana Edithe Andria-Mananjara ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Low Income ◽  
Food System ◽  
Production Systems ◽  
Dna Barcode ◽  
Diversity Indices ◽  
Low Income Countries ◽  
Wild Populations ◽  
Fast Development ◽  
Well Differentiated

The fast development of aquaculture over the past decades has made it the main source of fish protein and led to its integration into the global food system. Mostly originating from inland production systems, aquaculture has emerged as strategy to decrease malnutrition in low-income countries. The Nile tilapia (Oreochromis niloticus) was introduced to Madagascar in the 1950s, and is now produced nationally at various scales. Aquaculture mostly relies on fry harvested from wild populations and grow-out in ponds for decades. It has recently been diversified by the introduction of several fast-growing strains. Little is known how local genetic diversity compares to recently introduced strains, although high and comparable levels of genetic diversity have previously been observed for both wild populations and local stocks. Our study compares DNA barcode genetic diversity among eight farms and several strains belonging to three species sampled. DNA-based lineage delimitation methods were applied and resulted in the detection of six well differentiated and highly divergent lineages. A comparison of DNA barcode records to sequences on the Barcode of Life Data System (BOLD) helped to trace the origin of several of them. Both haplotype and nucleotide diversity indices highlight high levels of mitochondrial genetic diversity, with several local strains displaying higher diversity than recently introduced strains. This allows for multiple options to maintain high levels of genetic diversity in broodstock and provides more options for selective breeding programs.

scholarly journals Controlling a Multicenter Outbreak Involving the New York/Japan Methicillin-ResistantStaphylococcus aureusClone

2007 ◽  
Vol 28 (7) ◽  
pp. 845-852 ◽  
Author(s):  
G. W. Coombs ◽  
H. Van Gessel ◽  
J. C. Pearson ◽  
M.-R. Godsell ◽  
F. G. O'Brien ◽  
...  
Keyword(s):  
Public Health ◽  
New York ◽  
Molecular Typing ◽  
Management Strategies ◽  
Research Unit ◽  
Management Policy ◽  
Teaching Hospitals ◽  
Term Care ◽  
Outbreak Management ◽  
Healthcare Facilities

Objective.To describe the control of an outbreak of infection and colonization with the New York/Japan methicillin-resistantStaphylococcus aureus(MRSA) clone in multiple healthcare facilities, and to demonstrate the importance of making an MRSA management policy involving molecular typing of MRSA into a statewide public health responsibility.Setting.A range of healthcare facilities, including 2 metropolitan teaching hospitals and a regional hospital, as well as several community hospitals and long-term care facilities in a nonmetropolitan healthcare region.Interventions.A comprehensive, statewide MRSA epidemiological investigation and management policy.Results.In May 2005, there were 3 isolates referred to the Western Australian Gram-Positive Bacteria Typing and Research Unit that were identified as the New York/Japan MRSA clone, a pandemic MRSA clone with the ability to spread and replace existing clones in a region. Subsequent investigation identified 28 additional cases of infection and/or colonization dating from 2002 onward, including 1 involving a colonized healthcare worker (HCW) who had previously been hospitalized overseas. Of the 31 isolates detected, 25 were linked epidemiologically and via molecular typing to the isolate recovered from the colonized HCW. Four isolates appeared to have been introduced separately from overseas. Although the isolate from the single remaining case patient was genetically indistinct from the isolates that spread within Western Australia, no specific epidemiological link could be established. The application of standard outbreak management strategies reduced further spread.Conclusions.The elimination of the New/York Japan MRSA clone in a healthcare region demonstrates the importance of incorporating MRSA management policy into statewide public health programs. The mainstays of such programs should include a comprehensive and effective outbreak identification and management policy (including pre-employment screening of HCWs, where applicable) and MRSA clone identification by multilocus sequence typing.

Relative Distribution and Incidence of Viruses Associated with Disease Outbreaks in Tomato Fields in Trinidad

2006 ◽  
Vol 7 (1) ◽  
pp. 29
Author(s):  
S. N. Rampersad
Keyword(s):  
Production Systems ◽  
Management Strategies ◽  
Disease Outbreaks ◽  
Tobacco Etch Virus ◽  
The Other ◽  
Multiple Infections ◽  
Relative Distribution ◽  
Tomato Production ◽  
Viral Pathogen ◽  
High Incidence

Tomato production in Trinidad has suffered considerable losses in yield and fruit quality due to infections of hitherto surmised etiology. In order to develop strategies for controlling viral diseases in tomato, the relative distribution and incidence of seven viruses that commonly infect tomato were determined. Of the 362 samples tested, Potato yellow mosaic Trinidad virus (PYMTV) was found in every farm except two and was present at relatively high incidence throughout the country. Tobacco mosaic virus (TMV) and Tobacco etch virus (TEV) were found in fewer farms and at lower incidences while the other viruses were absent. Single infections of either virus were more common than double infections and multiple infections were rare but present. The results indicated that PYMTV is the predominant and most important viral pathogen in tomato production systems in Trinidad; however, begomovirus disease management strategies will also have to accommodate controls Accepted for publication 10 January 2006. Published 9 March 2006.

Sign in / Sign up

Export Citation Format

Share Document