152 research outputs found

    General Description of Rhizoctonia Species Complex

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    With Brexit, inward investment will fall in the UK

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    Supply chains cross borders many times before components go into a final product in any EU country, write David Bailey, Nigel Driffield and Michail Karoglo

    Deciphering core microbiota in rhizosphere soil and roots of healthy and Rhizoctonia solani-infected potato plants from various locations

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    Black scurf caused by Rhizoctonia solani severely affects potato production. Through amplification of V3-V4 and ITS1-5f variable regions of 16S and internal transcribed spacer (ITS) rRNA, the study was based on the location (Kunming, Qujing, and Zhaotong), plant components (rhizosphere soil and roots), and sample types (healthy and diseased) to assess the diversity of bacterial and fungal communities. We found plant components significantly influence microbial diversity, with rhizosphere soil being more diverse than roots, and the microbial community in the root is mainly derived from the rhizosphere soil. Moreover, the rhizosphere soil and roots of healthy potato plants exhibit greater microbial diversity compared to those of potato plants infected by Rhizoctonia solani. Bacterial phyla Actinobacteriota and Acidobacteriota were enriched in rhizosphere soil compared to that of roots, whereas Proteobacteria and Cyanobacteria showed the opposite trend. Fungal phylum Ascomycota was found in low relative abundance in rhizosphere soil than in roots, whereas Basidiomycota showed the opposite trend. Bacterial genera including Streptomyces, Lysobacter, Bacillus, Pseudomonas, Ensifer, Enterobacter, and the Rhizobium group (Allorhizobium, Neorhizobium, Pararhizobium, Rhizobium), along with fungal genera such as Aspergillus, Penicillium, Purpureocillium, and Gibberella moniliformis, have the potential ability of plant growth promotion and disease resistance. However, most fungal species and some bacterial species are pathogenic to potato and could provide a conducive environment for black scurf infection. Interaction within the bacterial network increased in healthy plants, contrasting with the trend in the fungal network. Our findings indicate that R. solani significantly alters potato plant microbial diversity, underscoring the complexity and potential interactions between bacterial and fungal communities for promoting potato plant health and resistance against black scurf

    Genome sequencing and comparative genome analysis of Rhizoctonia solani AG-3

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    Rhizoctonia solani AG-3 is a plant pathogenic fungus that belongs to the group of multinucleate Rhizoctonia. According to its internal transcribed spacer (ITS) cluster analysis and host range, it is divided into TB, PT, and TM subgroups. AG-3 TB mainly causes tobacco target spots, AG-3 PT mainly causes potato black scurf, and AG-3 TM mainly causes tomato leaf blight. In our previous study, we found that all 36 tobacco target spot strains isolated from Yunnan (Southwest China) were classified into AG-3 TB subgroup, while only two of the six tobacco target spot strains isolated from Liaoning (Northeast China) were classified into AG-3 TB subgroup, and the remaining four strains were classified into AG-3 TM subgroup, which had a unique taxonomic status, and there was no previous report on the whole genome information of AG-3 TM subgroup. In this study, the whole genomes of R. solani AG-3 strains 3T-1 (AG-3 TM isolated from Liaoning) and MJ-102 (AG-3 TB isolated from Yunnan) isolated from tobacco target spot in Liaoning and Yunnan were sequenced by IIumina and PacBio sequencing platforms. Comparative genomic analysis was performed with the previously reported AG-3 PT strain Rhs1AP, revealing their differences in genomes and virulence factors. The results indicated that the genome size of 3T-1 was 42,103,597 bp with 11,290 coding genes and 49.74% GC content, and the genome size of MJ-102 was 41,908,281 bp with 10,592 coding genes and 48.91% GC content. Through comparative genomic analysis with the previously reported strain Rhs1AP (AG-3 PT), it was found that the GC content between the genomes was similar, but the strains 3T-1 and MJ-102 contained more repetitive sequences. Similarly, there are similarities between their virulence factors, but there are also some differences. In addition, the results of collinearity analysis showed that 3T-1 and MJ-102 had lower similarity and longer evolutionary distance with Rhs1AP, but the genetic relationship between 3T-1 and MJ-102 was closer. This study can lay a foundation for studying the molecular pathogenesis and virulence factors of R. solani AG-3, and revealing its genomic composition will also help to develop more effective disease control strategies

    Knowledge, attitudes and practices relating to antibiotic use and antibiotic resistance among backyard pig farmers in rural Shandong province, China

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    China is among the world's largest consumers of antibiotics for livestock, and the demand for meat protein continues to rise. Pig production takes place at a range of facilities, including backyard pig farms. The aim of this study was to describe the knowledge, attitudes and practices of backyard pig farmers concerning antibiotic use and resistance, and to observe household storage of antibiotics for use in pigs. We conducted a cross-sectional questionnaire survey among 271 rural residents with backyard pig farms in 12 villages in one town in Shandong province. The median number of pigs per backyard farm was 14, and 82 % (222/271) of participants reported not having had any training about raising pigs. Eighteen percent of participants (48/271) reported always or often adding antibiotics to feed to keep pigs healthy and prevent diseases, and a third (88/271) of participants believed that pigs should be given antibiotics when they stop eating. Thirty percent (82/271) reported having bought antibiotics in the previous year without having first spoken with a veterinarian. Antibiotics accounted for over half of all medicines stored (55 %, 197/358), and were observed in 31 % of all households (83/271). Less than half of participants (45 %, 37/83) from households in which antibiotics for pig use were found knew that they were storing antibiotics. The most common class of antibiotics stored for use in pigs was (Q)J01C betalactam antibiotics, penicillins (19 %, 37/197), followed by (Q)J01F macrolides, lincosamides and streptogramins (14 %, 28/197), and (Q)J01M quinolones (12 %, 25/197). These results provide important insights into how backyard pig farmers are using antibiotics in rural China and suggest potential targets for interventions to reduce unnecessary and inappropriate use

    Infection with blast fungus ( Magnaporthe orzyae) leads to increased expression of an arabinogalactan-protein epitope in both susceptible and resistant rice cultivars

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    Blast fungus (Magnaporthe orzyae) is the most serious pathogen of rice. As such, the objective of the current study was to investigate the infection process using a selected panel of anti-plant extracellular matrix antibodies, in infected leaves from three rice cultivars that display varying degrees of resistance to the pathogen; at selected time points post inoculation. An arabinogalactan-protein (AGP) epitope, recognized by the antibody JIM13, was shown to be temporally and spatially regulated during the infection, in all three cultivars. Prior to inoculation, expression of the epitope was confined to the epidermis, sclerenchyma, phloem, xylem and bundle sheath. As the infection progressed, the intensity of labeling increased in all the aforementioned cell types and spread to the mesophyll. Immunogold transmission electron microscopy, revealed this epitope to be most abundant at the plasma membrane. These data suggest that this epitope is borne on a plasma-membrane-associated AGP, which may act as a pattern recognition receptor (PRR), involved in the basal immune response to infection with blast fungus, in both resistant and susceptible rice cultivars. As such, this study represents the first report of a membrane – associated arabinogalactan-protein in rice, which once cloned, could be of utility in future breeding programs/genetic modification to improve the basal immune response to blast fungus and other pathogens, in this globally important food crop

    Chlorimuronethyl Resistance Selectable Marker Unsuited for the transformation of rice blast fungus (Magnaporthe grisea)

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    Abstract: Chlorimuronethyl resistance gene is increasingly used as a selectable marker for transformation, especially fungal transformation. Magnaporthe grisea is an important model organism for investigating fungal pathogenicity, and Agrobacterium tumefaciens-mediated transformation (ATMT) is used for functional mutagenesis of the fungus. However, our results showed that rice blast strains collected from infectious rice fields have highly conserved resistance to chlorimuronethyl, even comparable to transformants which carrying chlorimuronethyl resistance genes as selectable marker in laboratory conditions. PCR results showed that all tested field strains presented the amplified products of the same size as the selectable marker amplified from plasmid carrying chlorimuronethyl gene. Sequence analysis of PCR products amplified from field strains confirmed that field strains harbored the highly identity homolog of chlorimuronethyl resistance gene. Blast search in GenBank suggested that the fragment is presenting in reference genome sequence of 70-15, but it is not a wide-spread gene in other organisms, excepted for Herpetosiphon aurantiacus. Although the origin and reason of the conserved chlorimuronethyl resistance gene in field isolates of blast fungus is unclear, the ecological function of the gene is noteworthy

    Effect of Double-Ovsynch and Presynch-Ovsynch on postpartum ovarian cysts and inactive ovary in high-yielding dairy cows

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    IntroductionOptimizing the management of dairy cattle reproduction can reduce postpartum ovarian disease in high-yielding dairy cows and thus enhance ranch economic benefit. The hypothesis of this study was that the Double-Ovsynch (DO) protocol in high-producing dairy cows would result in a lower incidence of follicular cysts but a higher incidence of luteal cysts compared to those undergoing the Presynch-Ovsynch (PS) protocol.MethodsIn this experiment, 384 cows (204 primiparous and 180 multiparous) were allocated to the DO group, which followed the protocol: GnRH-7d-PGF2α-3d-GnRH-7d-Ovsynch-56 h (GnRH-7d-PGF2α-56 h-GnRH-16hTAI), starting on 39 ± 3 days in milk (DIM). Additionally, 359 cows (176 primiparous and 183 multiparous) were assigned to the PS group, which followed the protocol: PGF2α-14d-PGF2α-12d-Ovsynch-56 h, starting on 31 ± 3 DIM. In DO, B-mode ultrasound examinations were conducted 1 day after the GnRH-7d-PGF2α-3d-GnRH protocol to diagnose the presence of ovarian diseases followed by reexamination after 7 days of suspected cases. In PS, B-mode ultrasound examinations were conducted 1 day after the PGF2α-14d-PGF2α protocol to diagnose the presence of ovarian diseases followed by reexamination after 7 days. For all cows confirmed to having ovarian diseases, a second B-mode ultrasound examination was conducted at the time of the second GnRH and timed artificial insemination (TAI). If the ovary showed a normal developing follicle in combination with normal ovulation, the ovarian disease was considered to be cured.ResultsThe current study revealed no significant difference in the overall incidence and cure rate of postpartum ovarian diseases between DO and PS (incidence rate: 3.9% vs. 6.7%, cure rate: 50% vs. 41.7%, DO vs. PS). Also, there was no significant difference in the incidence and cure rate of luteal cysts between DO and PS (incidence rate: 2.9% vs. 2.2%, cure rate: 50.0% vs. 50.0%). The incidence of follicular cysts was significantly lower in the DO group than in the PS group (0.8% vs. 2.8%, DO vs. PS, p = 0.037), but there was no significant difference in the cure rates (66.7% vs. 50%). The occurrence of inactive ovary was lower in DO compared to PS (0.2% vs. 1.7%, p = 0.047). There was no significant difference in the pregnancy rate between the DO and PS groups (48.2% vs. 41.8%), although the DO group had a higher rate. What is different from our assumption is that PS did not effectively reduce the incidence of postpartum luteal cysts

    Crop Diversity for Yield Increase

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    Traditional farming practices suggest that cultivation of a mixture of crop species in the same field through temporal and spatial management may be advantageous in boosting yields and preventing disease, but evidence from large-scale field testing is limited. Increasing crop diversity through intercropping addresses the problem of increasing land utilization and crop productivity. In collaboration with farmers and extension personnel, we tested intercropping of tobacco, maize, sugarcane, potato, wheat and broad bean – either by relay cropping or by mixing crop species based on differences in their heights, and practiced these patterns on 15,302 hectares in ten counties in Yunnan Province, China. The results of observation plots within these areas showed that some combinations increased crop yields for the same season between 33.2 and 84.7% and reached a land equivalent ratio (LER) of between 1.31 and 1.84. This approach can be easily applied in developing countries, which is crucial in face of dwindling arable land and increasing food demand
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