An integrated approach for increasing breeding efficiency in apple and peach in Europe

Despite the availability of whole genome sequences of apple and peach,there has been a considerable gap between genomics and breeding.To bridge the gap,the European Union funded the FruitBreedomics project(March 2011 to August 2015)involving 28 research institutes and private companies.Three complementary approaches were pursued:(i)tool and software development,(ii)deciphering genetic control of main horticultural traits taking into account allelic diversity and(iii)developing plant materials,tools and methodologies for breeders.Decisive breakthroughs were made including the making available of ready-to-go DNA diagnostic tests for Marker Assisted Breeding,development of new,dense SNP arrays in apple and peach,new phenotypic methods for some complex traits,software for gene/QTL discovery on breeding germplasm via Pedigree Based Analysis(PBA).This resulted in the discovery of highly predictive molecular markers for traits of horticultural interest via PBA and via Genome Wide Association Studies(GWAS)on several European genebank collections.FruitBreedomics also developed pre-breeding plant materials in which multiple sources of resistance were pyramided and software that can support breeders in their selection activities.Through FruitBreedomics,significant progresses were made in the field of apple and peach breeding,genetics,genomics and bioinformatics of which advantage will be made by breeders,germplasm curators and scientists.A major part of the data collected during the project has been stored in the FruitBreedomics database and has been made available to the public.This review covers the scientific discoveries made in this major endeavour,and perspective in the apple and peach breeding and genomics in Europe and beyond.

Small mammal community composition impacts bank vole (Clethrionomys glareolus) population dynamics and associated seroprevalence of Puumala orthohantavirus

Rodents are important reservoirs for zoonotic pathogens that cause diseases in humans.Biodiversity is hypoth-esized to be closely related to pathogen prevalence through multiple direct and indirect pathways.For example,the presence of non-host species can reduce contact rates of the main reservoir host and thus reduce the risk of transmission(“dilution effect”).In addition,an overlap in ecological niches between two species could lead to increased interspecific competition,potentially limiting host densities and reducing density-dependent pathogen transmission processes.In this study,we investigated the relative impact of population-level regulation of direct and indirect drivers of the prevalence of Puumala orthohantavirus(PUUV)in bank voles(Clethrionomys glareolus)during years with high abundance.We compiled data on small mammal community composition from four regions in Germany between 2010 and 2013.Structural equation modeling revealed a strong seasonality in PUUV control mechanisms in bank voles.The abundance of shrews tended to have a negative relationship with host abundance,and host abundance positively influenced PUUV seroprevalence,while at the same time increasing the abundance of competing non-hosts like the wood mouse(Apodemus sylvaticus)and the yellow-neckedfield mouse(Apodemusflavicollis)were associated with reduced PUUV seroprevalence in the host.These results indicate that for PUUV in bank voles,dilution is associated with increased interspecific competition.Anthropogenic pressures leading to the decline of Apodemus spp.in a specific habitat could lead to the amplification of mechanisms promoting PUUV transmission within the host populations.

Herbicidal Effects of Fungicides on Arable Weeds

In the present study, the herbicidal effects of two fungicides with the active ingredients expoxiconazole, fluxapyroxad, pyraclostrobin and fenpropimorph on the two arable weeds Lamium purpureum L. and Chenopodium album L. were investigated. The experiments were conducted in a climate chamber under defined conditions. Sowing pods were prepared and plants at the cotyledon leaf stage were pricked out in test pods. Fungicides were applied at six application rates: 0%, 12.5%, 25%, 50%, 100% and 200% of the maximum registered dose rate in Germany. Seven days after application, the first assessment was conducted, regarding growth stage, quantity of plants and visible plant damage. Fourteen days after application, the second and final assessment was conducted, regarding growth stage, quantity of plants, visible plant damage and the fresh weight of the plants. There were herbicidal effects of the fungicides, which were presumably due to the active ingredient epoxiconazole. Epoxiconazole has effects on enzymes that are dependent on cytochrome P-450 and inhibits sterol biosynthesis and probably gibberellin synthesis. By doing so, these fungicides have similar effects to plant growth regulators. Weed species showed differential sensitivities, contractions and growth inhibition and ED50-values were calculated. Notwithstanding the probably minor relevance of the present results in agricultural practice, some effects on arable weeds might result if fungicides are applied at an early growth stage in the field. In some cases, the crop-weed competition could be shifted to the benefit of the crop. Nevertheless, the results are interesting for the field of weed research and for the assessment of the ecotoxicology of fungicides.

Testing method and distribution characteristics of spatial pesticide spraying deposition quality balance for unmanned aerial vehicle

In order to explore the spatial pesticide spraying deposition distribution,the downwash flow field characteristics for unmanned aerial vehicle(UAV)pesticide application with accurate flight height and velocity and the relationship of these two aspects,a novel measurement method was proposed in this paper.A model‘3WQF80-10’single-rotor diesel UAV was tested using this method in wheat field and the effects of flight direction,flight parameters and crosswind on the distribution of spatial spraying deposition quality balance(SSDQB)and the downwash flow field distribution were researched.A cuboid aluminum sampling frame of spatial spraying deposition quality balance(SFSSDQB)with monofilament wires was made for collecting the droplets in four directions,and a set of multi-channel micro-meteorology measurement system(MMMS)was applied for measuring the downwash wind speed in three directions.Besides,BeiDou Navigation Satellite System(BNSS)was used for controlling and recording the working height,velocity and track of this model of single-rotor UAV.The results showed the distribution of the spatial spray deposition and the downwash flow field of UAV could be measured effectively at exact flight height and velocity via this method.When the average wind speed was 0.9 m/s,the average temperature was 31.5℃ and the average relative humidity was 34.1%,and the average distribution ratios of spraying deposition for model‘3WQF80-10’UAV on the upwind part,the top part,the downwind part and the bottom part were 4.4%,2.3%,50.4%and 43.7%,respectively.The flight directions of forward and backward had an impact on droplet deposition distribution and the working effect of flying backwards,with 60%of deposition ratio of the bottom part of the SFSSDQB,was better than flying forward.There was a linear negative correlation between the coefficient of variation(CV)of the bottom part and the flight height and the coefficient of determination was 0.9178,which means that the deposition distribution becomes more uniform with the increase of height.Additionally,there was a linear positive correlation between weighted mean deposition rate and crosswind speed and the coefficient of determination was 0.9684,which shows the deposition distribution gets more concentrated towards the downwind part with the rise of crosswind speed.Therefore,according to the results of tests of downwash airflow speed,it is shown that regardless of the flight direction and height and the crosswind,all these factors influence the droplet deposition distribution via weakening the intensity of the downwash airflow field in the direction perpendicular to the ground.The results can provide valuable information for the research of UAV pesticide application techniques and the establishment of the standard of spraying deposition and drift tests of UAV in crop field.

The status of fertility control for rodents—recent achievements and future directions

Management of overabundant rodents at a landscape scale is complex but often required to sustainably reduce rodent abundance below damage thresholds.Current conventional techniques such as poisoning are not species specific,with some approaches becoming increasingly unacceptable to the general public.Fertility control,first proposed for vertebrate pest management over 5 decades ago,has gained public acceptance because it is perceived as a potentially more species-specific and humane approach compared with many lethal methods.An ideal fertility control agent needs to induce infertility across one or more breeding seasons,be easily delivered to an appro-priate proportion of the population,be species specific with minimal side-effects(behavioral or social structure changes),and be environmentally benign and cost effective.To date,effective fertility control of rodents has not been demonstrated at landscape scales and very few products have achieved registration.Reproductive targets for fertility control include disrupting the hormonal feedback associated with the hypothalamic-pituitary-gonadal axis,gonad function,fertilization,and/or early implantation.We review progress on the oral delivery of various agents for which laboratory studies have demonstrated efficacy in females and/or males and synthesize progress with the development and/or use of synthetic steroids,plant extracts,ovarian specific peptides,and immunocontracep-tive vaccines.There are promising results forfield application of synthetic steroids(levonorgestrel,quinestrol),chemosterilants(4-vinylcyclohexene diepoxide),and some plant extracts(triptolide).For most fertility control agents,more research is essential to enable their efficient and cost-effective delivery such that rodent impacts at a population level are mitigated and food security is improved.