Sustainable management of transboundary pests requires holistic and inclusive solutions

A Synoptic Review of Plant Disease Epidemics and Outbreaks Published in 2022

This scientometric study reviews the scientific literature and CABI distribution records published in 2022 to find evidence of major disease outbreaks and first reports of pathogens in new locations or on new hosts. This is the second time we have done this, and this study builds on our work documenting and analyzing reports from 2021. Pathogens with three or more articles identified in 2022 literature were Xylella fastidiosa, Bursaphelenchus xylophilus, Meloidogyne species complexes, 'Candidatus Liberibacter asiaticus', Raffaelea lauricola, Fusarium oxysporum formae specialis, and Puccinia graminis f. sp. tritici. Our review of CABI distribution records found 29 pathogens with confirmed first reports in 2022. Pathogens with four or more first reports were Meloidogyne species complexes, Pantoea ananatis, grapevine red globe virus, and Thekopsora minima. Analysis of the proportion of new distribution records from 2022 indicated that grapevine red globe virus, sweet potato chlorotic stunt virus, and 'Ca. Phytoplasma vitis' may have been actively spreading. As we saw last year, there was little overlap between the pathogens identified by reviewing scientific literature versus distribution records. We hypothesize that this lack of concordance is because of the unavoidable lag between first reports of the type reported in the CABI database of a pathogen in a new location and any subsequent major disease outbreaks being reported in the scientific literature, particularly because the latter depends on the journal policy on types of papers to be considered, whether the affected crop is major or minor, and whether the pathogen is of current scientific interest. Strikingly, too, there was also no overlap between species assessed to be actively spreading in this year's study and those identified last year. We hypothesize that this is because of inconsistencies in sampling coverage and effort over time and delays between the first arrival of a pathogen in a new location and its first report, particularly for certain classes of pathogens causing only minor or non-economically damaging symptoms, which may have been endemic for some time before being reported. In general, introduction of new pathogens and outbreaks of extant pathogens threaten food security and ecosystem services. Continued monitoring of these threats is essential to support phytosanitary measures intended to prevent pathogen introductions and management of threats within a country.

A reverse transcription loop-mediated isothermal amplification assay for quick detection of tomato mosaic virus

Tomato mosaic virus (ToMV), an economically important virus that affects a wide range of crops, is highly contagious, and its transmission is mediated by mechanical means, and through contaminated seeds or planting materials, making its management challenging. To contain its wide distribution, early and accurate detection of infection is required. A survey was conducted between January and May, 2023 in major tomato growing counties in Kenya, namely, Baringo, Kajiado, Kirinyaga and Laikipia, to establish ToMV disease incidence and to collect samples for optimization of the reverse transcription loop-mediated isothermal amplification assay (RT-LAMP) assay. A RT-LAMP assay, utilizing primers targeting the coat protein, was developed and evaluated for its performance. The method was able to detect ToMV in tomato samples within 4:45 minutes, had a 1,000-fold higher sensitivity than conventional reverse transcription polymerase chain reaction (RT-PCR) method and was specific to ToMV. Furthermore, the practical applicability of the assay was assessed using tomato samples and other solanaecous plants. The assay was able to detect the virus in 14 tomato leaf samples collected from the field, compared to 11 samples detected by RT-PCR, further supporting the greater sensitivity of the assay. To make the assay more amenable for on-site ToMV detection, a quick-extraction method based on alkaline polyethylene glycol buffer was evaluated, which permitted the direct detection of the target virus from crude leaf extracts. Due to its high sensitivity, specificity and rapidity, the RT-LAMP method could be valuable for field surveys and quarantine inspections towards a robust management of ToMV infections.

The status and natural impact of floriculture production in Ethiopia: a systematic review

Ethiopia's floriculture industry is exceedingly emerging, and, currently, it ranks as the sixth largest exporter of roses worldwide and second largest in Africa. Currently, many flowers, such as rose, gypsophila, carnations, and chrysanthemum, are growing. However, floriculture farms are contributing a high level of health risks and environmental problems in Ethiopia. Thus, the purpose of this paper is to scrutinize the status and impacts of floriculture industries in Ethiopia. The floriculture division is an emerging sector in Ethiopia, and the number of farms, income, job opportunities, and diversity of flowers are increasing. However, the health risks and environmental fates of the sector are also increasing. Ethiopian floriculture farms lack waste disposal technologies and workers' protective equipment and safety, and the chemicals, plastics, and corrugated irons used in the farms are carelessly disposed everywhere. Pesticides, plastics, and fertilizers are also freely discharged into water bodies and terrestrial land, which is causing the development of health risks; aquatic life hazards; and soil, water, and air pollution. However, Ethiopia has no strong and functional system or structure to control the impacts of floriculture farms. The government and the farm owners are not thoughtful about the environmental issues, health concerns, and socioeconomic impacts of the wastes. The government lacks regular control and assessment of farms, and the farms are engaging for their profit. Nevertheless, developed countries are currently using both natural and modern technologies to manage floricultural wastes. Ethiopia should therefore suggest manageable possible approaches and sound management strategies based on the findings of the analyses.

Complete Genome Sequence Analysis of Bacillus subtilis Bbv57, a Promising Biocontrol Agent against Phytopathogens

Plant growth-promoting rhizobacteria (PGPR) are a group of root-associated beneficial bacteria emerging as one of the powerful agents in sustainable plant disease management. Among the PGPR, Bacillus sp. has become a popular biocontrol agent for controlling pests and the diseases of several crops of agricultural and horticultural importance. Understanding the molecular basis of the plant growth-promoting and biocontrol abilities of Bacillus spp. will allow us to develop multifunctional microbial consortia for sustainable agriculture. In our study, we attempted to unravel the genome complexity of the potential biocontrol agent Bacillus subtilis Bbv57 (isolated from the betelvine’s rhizosphere), available at TNAU, Coimbatore. A WGS analysis generated 26 million reads, and a de novo assembly resulted in the generation of 4,302,465 bp genome of Bacillus subtilis Bbv57 containing 4363 coding sequences (CDS), of which 4281 were functionally annotated. An analysis of 16S rRNA revealed its 100% identity to Bacillus subtilis IAM 12118. A detailed data analysis identified the presence of >100 CAZymes and nine gene clusters involved in the production of secondary metabolites that exhibited antimicrobial properties. Further, Bbv57 was found to harbor 282 unique genes in comparison with 19 other Bacillus strains, requiring further exploration.