Pesticide use in banana plantations in Costa Rica-A review of environmental and human exposure, effects and potential risks

Biodiversity is declining on a global scale. Especially tropical ecosystems, containing most of the planetary biodiversity, are at risk. Agricultural monocrop systems contribute to this decline as they replace original hab-itats and depend on extensive use of synthetic pesticides that impact ecosystems. In this review we use large-scale banana production for export purposes in Costa Rica as an example for pesticide impacts, as it is in production for over a century and uses pesticides extensively for more than fifty years. We summarise the research on pesticide exposure, effects and risks for aquatic and terrestrial environment, as well as for human health. We show that exposure to pesticides is high and relatively well-studied for aquatic systems and humans, but hardly any data are available for the terrestrial compartment including adjacent non target ecosystems such as rainforest fragments. Ecological effects are demonstrated on an organismic level for various aquatic species and processes but are not available at the population and community level. For human health studies exposure evaluation is crucial and recognised effects include various types of cancer and neurobiological dysfunctions particularly in children. With the many synthetic pesticides involved in banana production, the focus on insecticides, revealing highest aquatic risks, and partly herbicides should be extended to fungicides, which are applied aerially over larger areas. The risk assessment and regulation of pesticides so far relies on temperate models and test species and is therefore likely underestimating the risk of pesticide use in tropical ecosystems, with crops such as banana. We highlight further research approaches to improve risk assessment and, in parallel, urge to follow other strategies to reduce pesticides use and especially hazardous substances

Fungicides: An Overlooked Pesticide Class?

Fungicides are indispensable to global food security and their use is forecasted to intensify. Fungicides can reach aquatic ecosystems and occur in surface water bodies in agricultural catchments throughout the entire growing season due to their frequent, prophylactic application. However, in comparison to herbicides and insecticides, the exposure to and effects of fungicides have received less attention. We provide an overview of the risk of fungicides to aquatic ecosystems covering fungicide exposure (i.e., environmental fate, exposure modeling, and mitigation measures) as well as direct and indirect effects of fungicides on microorganisms, macrophytes, invertebrates, and vertebrates. We show that fungicides occur widely in aquatic systems, that the accuracy of predicted environmental concentrations is debatable, and that fungicide exposure can be effectively mitigated. We additionally demonstrate that fungicides can be highly toxic to a broad range of organisms and can pose a risk to aquatic biota. Finally, we outline central research gaps that currently challenge our ability to predict fungicide exposure and effects, promising research avenues, and shortcomings of the current environmental risk assessment for fungicides.</p

The draft genome sequence of European pear (Pyrus communis L. ‘Bartlett’)

We present a draft assembly of the genome of European pear (Pyrus communis) ‘Bartlett’. Our assembly was developed employing second generation sequencing technology (Roche 454), from single-end, 2 kb, and 7 kb insert paired-end reads using Newbler (version 2.7). It contains 142,083 scaffolds greater than 499 bases (maximum scaffold length of 1.2 Mb) and covers a total of 577.3 Mb, representing most of the expected 600 Mb Pyrus genome. A total of 829,823 putative single nucleotide polymorphisms (SNPs) were detected using re-sequencing of ‘Louise Bonne de Jersey’ and ‘Old Home’. A total of 2,279 genetically mapped SNP markers anchor 171 Mb of the assembled genome. Ab initio gene prediction combined with prediction based on homology searching detected 43,419 putative gene models. Of these, 1219 proteins (556 clusters) are unique to European pear compared to 12 other sequenced plant genomes. Analysis of the expansin gene family provided an example of the quality of the gene prediction and an insight into the relationships among one class of cell wall related genes that control fruit softening in both European pear and apple (Malus×domestica). The ‘Bartlett’ genome assembly v1.0 (http://www.rosaceae.org/species/pyrus/py​rus_communis/genome_v1.0) is an invaluable tool for identifying the genetic control of key horticultural traits in pear and will enable the wide application of marker-assisted and genomic selection that will enhance the speed and efficiency of pear cultivar developmen

Molecular Mapping of Major Genes and QTLs in Pear

Pear breeding programs are mainly focused on resistance to biotic stress and fruit quality traits. In the last two decades, major efforts have been undertaken toward identification of major genes and quantitative trait loci (QTLs) linked to both biotic resistance and fruit quality traits, along with their associated molecular markers in order to enable marker-assisted selection and breeding. This chapter will cover most relevant results reported so far pertaining to markers and QTLs linked to resistance to pathogens and pests (such as fire blight, scab, brown and black spot, pear psylla, pear sludge, and blister mite), fruit quality (fruit size, firmness, skin overcolor, russeting, fruit sweetness, and fruit acidity), and other traits (such as tree habit, chilling requirement, and harvest time). Furthermore, summaries of findings of studies conducted before and after the beginning of the genomics era will be provided. In addition, all progenies and selected parental lines capable of conferring traits of interest to their progenies are described herein. The aim is to provide breeders with tools to identify pear ideotypes in which several traits can be combined into a single individual. Furthermore, knowledge of genes and their related functions should serve as the basis for pursuing new plant breeding technologies, such as cisgenesis or DNA editing. These unprecedented advances in genomics and breeding strategies promise to enable dramatic improvements in breeding efficiencies, even for pears, that will also reduce time and costs incurred in today\u2019s traditional genetic improvement efforts