scholarly journals The Diversity of Bacteria Associated with the Invasive Gall Wasp Dryocosmus kuriphilus, Its Galls and a Specialist Parasitoid on Chestnuts

Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 86
Author(s):  
Xiaohui Yang ◽  
Yu Hui ◽  
Daohong Zhu ◽  
Yang Zeng ◽  
Lvquan Zhao ◽  
...  

Dryocosmus kuriphilus (Hymenoptera: Cynipidae) induces galls on chestnut trees, which results in massive yield losses worldwide. Torymus sinensis (Hymenoptera: Torymidae) is a host-specific parasitoid that phenologically synchronizes with D. kuriphilus. Bacteria play important roles in the life cycle of galling insects. The aim of this research is to investigate the bacterial communities and predominant bacteria of D. kuriphilus, T. sinensis, D. kuriphilus galls and the galled twigs of Castanea mollissima. We sequenced the V5–V7 region of the bacterial 16S ribosomal RNA in D. kuriphilus, T. sinensis, D. kuriphilus galls and galled twigs using high-throughput sequencing for the first time. We provide the first evidence that D. kuriphilus shares most bacterial species with T. sinensis, D. kuriphilus galls and galled twigs. The predominant bacteria of D. kuriphilus are Serratia sp. and Pseudomonas sp. Furthermore, the bacterial community structures of D. kuriphilus and T. sinensis clearly differ from those of the other groups. Many species of the Serratia and Pseudomonas genera are plant pathogenic bacteria, and we suggest that D. kuriphilus may be a potential vector of plant pathogens. Furthermore, a total of 111 bacteria are common to D. kuriphilus adults, T. sinensis, D. kuriphilus galls and galled twigs, and we suggest that the bacteria may transmit horizontally among D. kuriphilus, T. sinensis, D. kuriphilus galls and galled twigs on the basis of their ecological associations.

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 426
Author(s):  
Xiao-Hui Yang ◽  
Xiang-Mei Li ◽  
Dao-Hong Zhu ◽  
Yang Zeng ◽  
Lv-Quan Zhao

Dryocosmus kuriphilus (Hymenoptera: Cynipidae) is a gall wasp that induces insect galls on chestnut trees and results in massive yield losses worldwide. Fungi can cause the necrosis of chestnut trees and the death of gall wasps. The aim of this research was to investigate the potential role of D. kuriphilus in the transmission of fungi. We sequenced the ribosomal RNA internal transcribed spacer region 1 of fungi in D. kuriphilus adults, associated insect galls and the galled twigs of Castanea mollissima, using high-throughput sequencing. We compared the species richness, α-diversity and community structure of fungi in D. kuriphilus adults, insect galls and the galled twigs. We provide the first evidence that D. kuriphilus adults shared most fungal species with associated insect galls and the galled twigs, and were dominated by Botryosphaeria sp., Aspergillus sp. and Diaporthe sp. We suggest D. kuriphilus adults may be potential vectors of plant pathogens and may facilitate the transmission of fungi between chestnut trees. Furthermore, the fungi may horizontally transmit among D. kuriphilus adults, associated insect galls and the galled twigs.


2019 ◽  
Vol 19 (4) ◽  
Author(s):  
Ambra Viviani ◽  
Rodolfo Bernardi ◽  
Andrea Cavallini ◽  
Elisabetta Rossi

Abstract Torymus sinensis Kamijo (Hymenoptera: Torymidae) is an alien parasitoid that is used in many areas of the world for biological control the Asian chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae). In Italy, this parasitoid was imported from Japan in 2003 and subsequently multiplied and released throughout the country. In this study, a phylogenetic investigation was carried out on insects from three different sites in northern Tuscany (Italy). Moreover, the possible hybridization between T. sinensis and some native Torymus species was evaluated. The conserved region 18S rRNA gene and the hypervariable ITS2 (Internal Transcribed Spacer 2) region of the ribosomal cistrone were selected as molecular markers. Sequencing the amplified products, after cloning, ruled out any hybridization between T. sinensis and the native Torymus species, and also confirmed the presence of two haplotypes for the Tuscan population of T. sinensis both for the region of the 18S rRNA gene as well as for the ITS2 region. These results confirm that the environmental impact of the alien parasitoid T. sinensis in the study site is acceptable, although an extensive and repeated monitoring would be desirable.


2016 ◽  
Author(s):  
Edward W Davis II ◽  
Alexandra J Weisberg ◽  
Javier F Tabima ◽  
Niklaus J. Grunwald ◽  
Jeff Chang

Understanding the population structure and genetic diversity of plant pathogens, as well as the effect of agricultural practices on pathogen evolution, are important for disease management. Developments in molecular methods have contributed to increasing the resolution for accurate pathogen identification but those based on analysis of DNA sequences can be less straightforward to use. To address this, we developed Gall-ID, a web-based platform that uses DNA sequence information from 16S rDNA, multilocus sequence analysis and whole genome sequences to group disease-associated bacteria to their taxonomic units. Gall-ID was developed with a particular focus on gall-forming bacteria belonging to Agrobacterium, Pseudomonas savastanoi, Pantoea agglomerans, and Rhodococcus. Members of these groups of bacteria cause growth deformation of plants, and some are capable of infecting many species of field, orchard, and nursery crops. Gall-ID also enables the use of high-throughput sequencing reads to search for evidence for homologs of characterized virulence genes, and provides downloadable software pipelines for automating multilocus sequence analysis, analyzing genome sequences for average nucleotide identity, and constructing core genome phylogenies. Lastly, additional databases were included in Gall-ID to help determine the identity of other plant pathogenic bacteria that may be in microbial communities associated with galls or causative agents in other diseased tissues of plants. The URL for Gall-ID is http://gall-id.cgrb.oregonstate.edu/.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2222 ◽  
Author(s):  
Edward W. Davis II ◽  
Alexandra J. Weisberg ◽  
Javier F. Tabima ◽  
Niklaus J. Grunwald ◽  
Jeff H. Chang

Understanding the population structure and genetic diversity of plant pathogens, as well as the effect of agricultural practices on pathogen evolution, is important for disease management. Developments in molecular methods have contributed to increase the resolution for accurate pathogen identification, but those based on analysis of DNA sequences can be less straightforward to use. To address this, we developed Gall-ID, a web-based platform that uses DNA sequence information from 16S rDNA, multilocus sequence analysis and whole genome sequences to group disease-associated bacteria to their taxonomic units. Gall-ID was developed with a particular focus on gall-forming bacteria belonging toAgrobacterium,Pseudomonas savastanoi,Pantoea agglomerans, andRhodococcus. Members of these groups of bacteria cause growth deformation of plants, and some are capable of infecting many species of field, orchard, and nursery crops. Gall-ID also enables the use of high-throughput sequencing reads to search for evidence for homologs of characterized virulence genes, and provides downloadable software pipelines for automating multilocus sequence analysis, analyzing genome sequences for average nucleotide identity, and constructing core genome phylogenies. Lastly, additional databases were included in Gall-ID to help determine the identity of other plant pathogenic bacteria that may be in microbial communities associated with galls or causative agents in other diseased tissues of plants. The URL for Gall-ID ishttp://gall-id.cgrb.oregonstate.edu/.


2019 ◽  
Author(s):  
Mustafa O. Jibrin ◽  
Gerald V. Minsavage ◽  
Erica M. Goss ◽  
Pamela D. Roberts ◽  
Jeffrey B. Jones

AbstractBackgroundGene transfer agents (GTAs) are phage-like mediators of gene transfer in bacterial species. Typically, strains of a bacteria species which have GTA shows more recombination than strains without GTAs. GTA-mediated gene transfer activity has been shown for few bacteria, with Rhodobacter capsulatus being the prototypical GTA. GTA have not been previously studied in plant pathogenic bacteria. A recent study inferring recombination in strains of the bacterial spot xanthomonads identified a Nigerian lineage which showed unusual recombination background. We initially set out to understand genomic drivers of recombination in this genome by focusing on mobile genetic elements.ResultsWe identified a unique cluster which was present in the Nigerian strain but absent in other sequenced strains of bacterial spot xanthomonads. The protein sequence of a gene within this cluster contained the GTA_TIM domain that is present in bacteria with GTA. We identified GTA clusters in other Xanthomonas species as well as species of Agrobacterium and Pantoea. Recombination analyses showed that generally, strains of Xanthomonas with GTA have more inferred recombination events than strains without GTA, which could lead to genome divergence.ConclusionThis study identified GTA clusters in species of the plant pathogen genera Xanthomonas, Agrobacterium and Pantoea which we have named XpGTA, AgGTA and PaGTA respectively. Our recombination analyses suggest that Xanthomonas strains with GTA generally have more inferred recombination events than strains without GTA. The study is important in understanding the drivers of evolution of bacterial plant pathogens.


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