Data on winged insect dynamics in melon crops in southeastern France

This article displays insect count data obtained in eleven field trials conducted between 2010 and 2019 in southeastern France. Winged insect abundances were monitored daily within melon crops during 8 to 11 weeks in May-July using a suction trap or a yellow pan trap. Aphids were identified under a stereomicroscope. In total, 29,709 winged aphids belonging to 216 taxa and 151,061 other flying insects were caught. Among possible uses, these data can populate larger multisite studies or larger time series investigating aphid community variations. They can also feed generic studies exploring temporal dependencies or species assemblages. They can stimulate new collaborations with entomologists keen on implementing molecular tools or taxonomic expertise on a large specimen collection

Sequencing viral siRNAs to identify previously undescribed viruses and viroids in a panel of ornamental plant samples structured as a matrix of pools

Ornamental plants constitute a largely unknown and potentially important source of pathogens affecting not only ornamental plants, but also major crop species. We have carried out studies using high-throughput sequencing of 21-24 nt RNAs from potentially virus-infected ornamental plants, followed by assembly of sequence scaffolds, to identify the virus and viroid genomes present in a panel of 67 plant samples representing 46 species belonging to the main sectors of the ornamental plant industry (cut flowers, pot plants, bulbs). A pilot study demonstrated that samples could be pooled (5 samples per pool), and the overall process simplified without loss of detection of important known pathogens. In a full-scale study, pools of 5 samples were organized in a 5 × 5 matrix to facilitate attribution of a sequence to a precise sample directly from analysis of the matrix. In the total of 67 samples analyzed in the two studies, partial sequences suggesting the presence of 25 previously unknown viruses and viroids were detected, including all types of virus and viroid genomes, and also showed four cases of known viruses infecting previously undescribed hosts. Furthermore, two types of potential mis-assembly were analyzed, and were shown to not affect the conclusions regarding the presence of the pathogens identified, but show that mis-assembly can affect the results when the objective is determining complete bona fide viral genome sequences. These results clearly confirm that ornamental plants constitute a potential source of unknown viruses and viroids that could have a major impact on agriculture, and that sequencing siRNAs of potentially virus- or viroid-infected ornamental plants is an effective means for screening for the presence of potentially important pathogens

An update of the host range of tomato spotted wilt virus

Among plant viruses, Tomato spotted wilt virus (TSWV) is considered as the most widespread and to have the largest host-range. This virus is responsible for numerous epidemics in different regions of the world, mainly in horticultural and floral crops, which are often destructive and cause heavy economic losses. The highly polyphagous na- ture, the efficiency of virus transmission and the biological activity of its vectors, the rapidity with which new variants arise, and difficulties in the control of the vectors, make TSWV one of the most feared plant viruses by growers of agricultural crops. Preventive and integrated cultural practices such as the eradication of weed hosts able to serve as virus reservoirs, combined with vector management strategies, play a crucial role in the control of the virus. Thus, the availability of an up-to-date list of TSWV host plants is a potentially useful reference for researchers and farmers.The current list of TSWV hosts consists of 1090 plants species belonging in 15 families of monocotyledonous plants, 69 families of dicotyledonous plants and one family of pteridophytes

The Am gene controlling resistance to Alfalfa mosaic virus in tomato is located in the cluster of dominant resistance genes on chromosome 6

The dominant gene Am from Lycopersicon hirsutum f. sp. glabratum PI134417 confers resistance to most strains of Alfalfa mosaic virus, including the recently identified necrotic strains. The phenotypic response includes a lack of symptom development following mechanical inoculation of leaves. To study the resistance mechanism controlled by Am, biological (back-inoculation to susceptible hosts), serological (double-antibody sandwich, enzyme-linked immunosorbent assay), and molecular (reverse transcription-polymerase chain reaction and hybridization with specific riboprobes) methods of virus detection have been conducted on mechanically inoculated PI134417 leaves. The virus was never recovered, indicating that Am acts by an inhibition of viral accumulation during the early events of the virus life cycle. Am has been mapped genetically to the short arm of tomato chromosome 6 in the resistance hotspot, which includes the R-genes Mi and Cf-2/Cf-5 and the quantitative resistance factors Ty-1, Ol-1, and Bw-5

Epidemiology and variability of tospoviruses in France

International audienc

Production d'un sérum polyclonal spécifique du parietaria mottle ilarvirus (PMoV), et étude de sa transmission par le pollen. Poster

International audienc