Sustainable Control Strategies Research Articles

Radioactivity and GMO-Free Sterile Insect Technology for the Sustainable Control of the Invasive Pest Drosophila suzukii.

Drosophila suzukii (D. suzukii), commonly known as the spotted wing drosophila, is a highly invasive crop pest that is difficult to control using chemical insecticides. To address the urgent need for alternative and more sustainable control strategies, the sterile insect technique (SIT) is improved, which involves the release of sterilized male insects to mate with fertile conspecifics, thereby reducing the size of the pest population in the subsequent generation. The three critical aspects that influence the success of SIT programs in D. suzukii are addressed. First, an accurate and nondestructive method is established to determine the sex of individual insects based on the differential weight of male and female pupae. Second, conditions for X-ray sterilization are systematically tested and an optimal dose (90kV/40Gy) is identified that ensures the efficient production of sterile D. suzukii for release. Finally, the inherent thermosensitivity of D. suzukii males is exploited to develop a temperature-based sterilization technique, offering an alternative or additional SIT method for this pest. These advances will contribute to the development of a comprehensive and effective strategy for the management of D. suzukii populations, reducing their impact on agriculture and helping to safeguard crop yields.

Efficacy of herbal extracts in the management of cactus pest, Dactylopius opuntiae (Hemiptera: Dactylopiidae) in Tigray Region, Ethiopia

Cactus (Opuntia ficus-indica) is a drought-resistant plant and the source of food and income for many farmers during the rainy season, and the only option to feed livestock during the dry seasons, especially in the southern part of the Tigray region of Ethiopia. The region is currently suffering from a damaging parasitoid of cactus called Dactylopius opuntiae- ficus biotype. An experimental study was conducted from August 2022 to February 2023 to investigate the efficacy of herbal extracts against cochineal insects. The experiment was conducted on the insecticidal property of methanol extracts of Solanum linnaenum, Euphorbia tirucalli, Nerium oleander, Tephrosia vogelii, Calpurnia aurea, Argemone Mexicana, Datura stramonium and Ricinus communis. Herbs were extracted, and their efficacy and LC50 were determined. Phytochemical screening for secondary metabolites was performed. There was a statistically significant difference in the mean mortality of insects across the levels of the herbs (F (8, 71) = 57.812, p = 0.0001, ƞ2 = 0.867) and the experimental extract concentrations (F (1, 71) = 4198.3, p = 0.0001, ƞ2 = 0.983). The individual extracts of S. linnaenum and N. oleander caused average mortality rates of 99.3% and 97.4%, respectively, at 5% extract concentration. Tannins and saponins were the major metabolites found in the extracts. The present study demonstrated the promising insecticidal efficacy of herbal extracts against the damaging cacti pest D. opuntia-ficus biotype, providing insights into sustainable pest control strategies for protecting vital cactus resources in the Tigray region.

Updates on traditional methods for combating malaria and emerging Wolbachia-based interventions.

The escalating challenge of malaria control necessitates innovative approaches that extend beyond traditional control strategies. This review explores the incorporation of traditional vector control techniques with emerging Wolbachia-based interventions. Wolbachia, a naturally occurring bacteria, offers a novel approach for combatting vector-borne diseases, including malaria, by reducing the mosquitoes' ability to transmit these diseases. The study explores the rationale for this integration, presenting various case studies and pilot projects that have exhibited significant success. Employing a multi-dimensional approach that includes community mobilization, environmental modifications, and new biological methods, the paper posits that integrated efforts could mark a turning point in the struggle against malaria. Our findings indicate that incorporating Wolbachia-based strategies into existing vector management programs not only is feasible but also heightens the efficacy of malaria control initiatives in different countries especially in Pakistan. The paper concludes that continued research and international collaboration are imperative for translating these promising methods from the laboratory to the field, thereby offering a more sustainable and effective malaria control strategy.

Temporal characteristics and health effects related to NO2, O3, and SO2 in an urban area of Iran

This study reports on temporal variations of NO2, O3, and SO2 pollutants and their related health effects in urban air of Khorramabad, Iran using AirQ 2.2.3 software. Based on data between 2015 and 2021, hourly NO2, O3, and SO2 concentrations increase starting at 6:00 a.m. local time until 9:00 p.m., 3:00 p.m., and 7:00 p.m. local time, respectively, before gradually decreasing. The highest monthly NO2, O3, and SO2 concentrations are observed in October, August, and September, respectively. Annual median NO2, O3, and SO2 concentrations range between 17 ppb and 38.8 ppb, 17.5 ppb–36.6 ppb, and ∼14 ppb–30.8 ppb, respectively. Two to 93 days and 17–156 days between 2015 and 2021 exhibit daily concentrations of NO2 and SO2 ≤ WHO AQGs, respectively, while 187–294 days have 8-h maximum O3 concentrations ≤ WHO AQGs. The mean excess mortality ascribed to respiratory mortality, cardiovascular mortality, hospital admissions for COPD, and acute myocardial infraction are 121, 603, 39, and 145 during 2015–2021, respectively. O3 is found to exert more significant health effects compared to SO2 and NO2, resulting in higher cardiovascular mortality. The gradual increase in NO2 and possibly O3 over the study period is suspected to be due to economic sanctions, while SO2 decreased due to regulatory activity. Sustainable control strategies such as improving fuel quality, promoting public transportation and vehicle retirement, applying subsidies for purchase of electric vehicles, and application of European emission standards on automobiles can help decrease target pollutant levels in ambient air of cities in developing countries.

A new biocontrol agent against old enemies: The potential of Trichogramma foersteri for the control of Spodoptera frugiperda and Spodoptera eridania

Species of the genus Trichogramma Westwood (Hymenoptera: Trichogrammatidae) are widely used for pest control, highlighting the importance of exploring new species for the advancement of biological control programs. The study aimed to evaluate the efficacy of Trichogramma foersteri Takahashi, a recently discovered species, in controlling Spodoptera frugiperda (JE Smith) and S. eridania (Stoll), two significant pests of numerous cash crops. Over three days, the research examined parasitism, non-reproductive mortality, and emergence rates for both pest species. Trichogramma foersteri demonstrated effective parasitism, reducing 144.1 ± 6.0 eggs (one layer) and 55.4 ± 4.0 eggs (two layers) of S. frugiperda, as well as controlling 150.7 ± 5.6 eggs of S. eridania. Non-reproductive effects contributed significantly to mortality, causing the demise of 192.6 ± 4.7 and 118.6 ± 3.8 eggs in one and two layers of S. frugiperda, and 294.7 ± 7.0 eggs in S. eridania. Within three days, T. foersteri controlled approximately 334.2 ± 7.6 and 174.0 ± 4.0 eggs of S. frugiperda in one and two layers, respectively, and 445.4 ± 7.2 eggs of S. eridania. The highest emergence of T. foersteri occurred on the first day of evaluation, with 80.4 % for S. frugiperda and 23.0 % for S. eridania. These findings underscore the potential of T. foersteri as an effective control agent for both pests and provide valuable insights for the development of sustainable pest control strategies.

Biolarvicide activity of extract and essential oil of culantro (Eryngium foetidum L.) on Culex quinquefasciatus larvae in silico and in vitro


 
 
 
 Background: Filariasis, a priority tropical disease in Indonesia, is transmitted by the Culex quinquefasciatus mosquito. The use of conventional synthetic larvicides can lead to environmental and health issues, including poisoning and resistance in target insect populations.
 Objective: This study explores the utilization of biolarvicides derived from culantro (Eryngium foetidum) to mitigate these adverse efects, focusing on analyzing the components and evaluating the larvicidal eficacy of both the extract and essential oil of E. foetidum.
 Method: This study employed a molecular docking approach to examine in silico biolarvicidal activity against the odorant binding protein (OBP) receptor and conducted in vitro experiments on Cx. quinquefasciatus larvae using varying concentrations of E. foetidum extract (100, 250, and 500 ppm) and essential oil (10, 50, and 100 ppm).
 Results: The in silico study identified hynokiflavone and longifenaldehyde as the compounds with the most potent activity, demonstrating binding a inities of -10.2 and -9.5 kcal/mol, respectively. The in vitro assays revealed that the E. foetidum extract achieved 75% larval mortality at an LC50 of 78.59 ppm, while the essential oil resulted in 88% mortality with an LC50 of 10.13 ppm.
 Conclusion:The extract and essential oil of E. foetidum exhibit significant biolarvicidal activity against Culex quinquefasciatus, offering promising plant-based alternatives to traditional larvicides, with implications for safer and more sustainable vector control strategies.
 
 
 

Integrated field application of T. viride, botanicals, and fungicides for managing early blight (Alternaria solani) and enhancement of plant growth, tuber nutritional quality, and potato yield

Early blight disease, incited by Alternaria solani, is the most deleterious foliar disease of potato and other solanaceous crops. Herein, to counter the early blight disease, T. viride (Tv), botanicals [neem (N) and garlic (G)], and fungicides [flusilazole (F) and kasugamycin (K)] in different combinations applied through tuber treatment (ST) and foliar spray (FS) were evaluated for disease suppression, germination percent, plant growth promotion, photosynthetic pigments, and yield components as well as the nutritional quality of tubers under field conditions during the 2018–2019 and 2019–2020 seasons. The results of two-year field experiments revealed that the combination of Tv+ F+ N (ST) + G+K (FS) efficiently suppressed the development of the early blight disease symptoms and recorded 21.63 and 18.37% disease severity (DS) as compared to untreated control, respectively at 30 days post-treatment (dpt). During the 2018–2019 seasons, potato tubers treated with Tv +F significantly increased tuber germination (97.78%), while Tv+ F+ N treated potato tubers exhibited 98.89% tuber germination during the 2019–2020 season. Additionally, the potato plants treated with the combination of Tv+ F+ N (ST) + G+K (FS) and challenge inoculated with A. solani positively increased plant growth promotion activities like shoot and root length, fresh and dry weight of shoot and root, number of branches/plant, and induced accumulation of photosynthetic pigments like chlorophyll-a, b, and total carotenoids content during both seasons. Furthermore, under A. solani inoculated conditions, treatment with Tv+ F+ N (ST) + G+K (FS) significantly increased all yield attributing traits and other parameters associated with tuber nutritional quality such as starch (1.79-and 1.68-fold, respectively), vitamin-C (1.51-and 1.58-fold, respectively), total nitrogen (1.31-and 1.33-fold, respectively), total phosphorus (1.53-and 1.60-fold, respectively), and total potassium content (1.42-and 1.45-fold, respectively) as compared to untreated control in both seasons. So, it can be concluded that among all the treatments, integrated treatment comprising of tuber treatment with T. viride, flusilazole, and neem extract + one foliar spray of garlic extract and kasugamycin was found very effective in reducing early blight disease, promoting the plant’s growth, and increasing the yield as well as nutritional quality of tubers in the field conditions. The inclusive results indicated that integrated application might be a sustainable and eco-friendly control strategy for potato growers to manage potato early blight and achieve higher yields and nutritional tubers.

Investigating the perceived versus actual gastrointestinal nematode challenge on extensive sheep farms

Extensive farming systems form an integral part of sheep production systems across Europe. However, with innate production handicaps, declining sheep numbers and narrow economic margins, production is becoming increasingly challenging threatening the future sustainability of the industry. Gastrointestinal nematodes (GINs) are a significant cause of production losses to the global sheep industry, with well-established resistance to the major anthelmintic groups. Traditionally, extensive farming systems are not thought to have a significant parasite challenge compared with intensive farms, but there is a need to identify the scale and importance of GINs on extensive farms to inform the need for sustainable control strategies. In this study, a questionnaire of extensive farmers (n=34) was conducted and parasitological data were collected from nine study farms to investigate the perceived versus actual GIN and anthelmintic resistance challenge faced by extensive farms. The results showed a production-limiting challenge on most farms, with a higher GIN challenge observed on improved pastures. Furthermore, over half of the extensive farmers perceived anthelmintic resistance to be a greater problem for intensive farmers, with only 20% of respondents reporting known anthelmintic resistance. However, all study farms had evidence of resistance to at least one group of anthelmintics. Consequently, this study has demonstrated that despite the traditional perception of parasitism on extensive farms, there is a need to increasingly consider its impact and take a proactive approach to sustainable control, with solutions tailored to their unique management.

Genomic characterization of Pseudomonas syringae pv. syringae from Callery pear and the efficiency of associated phages in disease protection.

The Pseudomonas syringae species complex is a heterogeneous group of plant pathogenic bacteria associated with a wide distribution of plant species. Advances in genomics are revealing the complex evolutionary history of this species complex and the wide array of genetic adaptations underpinning their diverse lifestyles. Here, we genomically characterize two P. syringae isolates collected from diseased Callery pears (Pyrus calleryana) in Berkeley, California in 2019 and 2022. We also isolated a lytic bacteriophage, which we characterized and evaluated for biocontrol efficiency. Using a multilocus sequence analysis and core genome alignment, we classified the P. syringae isolates as members of phylogroup 2, related to other strains previously isolated from Pyrus and Prunus. An analysis of effector proteins demonstrated an evolutionary conservation of effectoromes across isolates classified in PG2 and yet uncovered unique effector profiles for each, including the two newly identified isolates. Whole-genome sequencing of the associated phage uncovered a novel phage genus related to Pseudomonas syringae pv. actinidiae phage PHB09 and the Flaumdravirus genus. Finally, using in planta infection assays, we demonstrate that the phage was equally useful in symptom mitigation of immature pear fruit regardless of the Pss strain tested. Overall, this study demonstrates the diversity of P. syringae and their viruses associated with ornamental pear trees, posing spill-over risks to commercial pear trees and the possibility of using phages as biocontrol agents to reduce the impact of disease.IMPORTANCEGlobal change exacerbates the spread and impact of pathogens, especially in agricultural settings. There is a clear need to better monitor the spread and diversity of plant pathogens, including in potential spillover hosts, and for the development of novel and sustainable control strategies. In this study, we characterize the first described strains of Pseudomonas syringae pv. syringae isolated from Callery pear in Berkeley, California from diseased tissues in an urban environment. We show that these strains have divergent virulence profiles from previously described strains and that they can cause disease in commercial pears. Additionally, we describe a novel bacteriophage that is associated with these strains and explore its potential to act as a biocontrol agent. Together, the data presented here demonstrate that ornamental pear trees harbor novel P. syringae pv. syringae isolates that potentially pose a risk to local fruit production, or vice versa-but also provide us with novel associated phages, effective in disease mitigation.

On the Way to the Technological Development of Newly Selected Non-Saccharomyces Yeasts Selected as Innovative Biocontrol Agents in Table Grapes.

Post-harvest decay of fresh table grapes causes considerable annual production losses. The main fungal agents of decay both in pre- and post-harvest are B. cinerea, Penicillium spp., Aspergillus spp., Alternaria spp., and Cladosporium spp. To date, the use of agrochemicals and SO2 are the main methods to control grape molds in pre- and postharvest, respectively. Significant improvements, however, have already been made in to apply innovative and more environmentally sustainable control strategies, such as Biological Control Agents (BCAs), which can reduce disease severity in both pre- and post-harvest. In this study, 31 new non-Saccharomyces yeast strains, isolated from berries of native Apulian table grape genotypes, were tested for their in vivo effectiveness against grey mold of table grapes, resulting in two St. bacillaris ('N22_I1' and 'S13_I3'), one S. diversa ('N22_I3'), one A. pullulans ('OLB_9.1_VL') and one H. uvarum ('OLB_9.1_BR') yeast strains that were marked as efficient and good BCAs. Their mechanisms of action were characterized through in vitro assays, and additional characteristics were evaluated to assess the economic feasibility and viability for future technological employment. Their effectiveness was tested by reducing the working concentration, their antagonistic effect on a wide range of fungal pathogens, their ability to survive in formulations with long shelf life, and their safety to human health.

Special Issue “Sustainable Control Strategies of Plant Pathogens in Horticulture”

European Regulation No [...]

Developmental status of duku stem-canker in Jambi

Dead molt disease or duku stem-canker disease has been widely discussed in several studies. Some suspect it is caused by Phytophthora palmivora, or Ceratocystis fimbriata, and possibly Botryodiplodia spp. In the last decade, studies and discussions in control efforts have been carried out. Control studies using biological control strategies continue to be carried out, especially in the South Sumatera region, as well as control studies using pesticides have also received a lot of attention, but the control results have not reached a satisfactory stage. There are still many duku plants that have experienced widespread mortality. Finally, we will discuss about the research that has done into developing effective and sustainable control strategies.

Biology, Ecology, and Management of Flea Beetles in Brassica Crops.

Brassica vegetable and oilseed crops are attacked by several different flea beetle species (Chrysomelidae: Alticini). Over the past decades, most research has focused on two Phyllotreta species, Phyllotreta striolata and Phyllotreta cruciferae, which are major pests of oilseed rape in North America. More recently, and especially after the ban of neonicotinoids in the European Union, the cabbage stem flea beetle, Psylliodes chrysocephala, has become greatly important and is now considered to be the major pest of winter oilseed rape in Europe. The major challenges to flea beetle control are the prediction of population dynamics in the field, differential susceptibility to insecticides, and the lack of resistant plant cultivars and other economically viable alternative management strategies. At the same time, many fundamental aspects of flea beetle biology and ecology, which may be relevant for the development of sustainable control strategies, are not well understood. This review focuses on the interactions between flea beetles and plants and summarizes the literature on current management strategies with an emphasis on the potential for biological control in flea beetle management.

Fatty Acid Elongase Gene PcELO7 is Essential for Lipid Accumulation and Fecundity of Panonychus citri (Acari: Tetranychidae).

RNA interference (RNAi) has been proposed as a promising strategy for sustainable and ecofriendly pest control. The insect cuticle lipids were deposited on the body surface and functioned as a defense against chemical xenobiotics. They consisted of aliphatic compounds, including free fatty acids (FFAs). However, elongase of very long chain fatty acids (ELOs) is essential for FFA biosynthesis; the function of ELO is still unknown in many arthropods, including Panonychus citri (P. citri). In this study, three ELOs were cloned. Developmental-specific mRNA expression results revealed that three PcELOs were highly expressed in egg and adult females. Whereas PcELO7 was dominantly expressed in adult females. Under spirobudiclofen stress, ELOs mRNA expression had different changes, and PcELO7 was down-regulated. The silencing of PcELO7 resulted in a dramatic reduction of oviposition and hatchability. Significant reduction of FFA contents was also examined within PcELO7-repressed P. citri. In addition, we found that PcELO7 mRNA levels were related to fecundity and could affect triacylglycerol (TG) contents. The findings demonstrated that the introduction of dsPcELO7 via oral feeding induced the RNA interference-mediated silencing of a special target gene and could result in mortality and reproduction. In conclusion, PcELO7 is a special RNAi target for P. citri control, and its lethal mechanism might be disturbing lipids biosynthesis.

Refugia, climatic conditions and farm management factors as drivers of adaptation in Nematodirus battus populations

Parasites are known for their ability to rapidly adapt to changing conditions. For parasitic helminths, changes in climate, along with farming and management practices associated with the intensification of livestock farming, provide novel challenges which can impact on their epidemiology and control. The sustainability of livestock production partially relies on effective control of helminth infection. Therefore, understanding changes in parasite behaviour, and what drives these, is of great importance. Nematodirus battus is an economically important helminth in the UK and temperate regions. Its infective larvae typically overwinter in eggs on pasture and hatch synchronously in spring, causing acute disease in lambs. Attempts to control disease typically rely on whole-flock benzimidazole (BZ) treatments. In recent years, the emergence of BZ-resistance, alongside the hatching of eggs without the classical over-winter ‘chill stimulus’, have made N. battus more difficult to control. In three previous studies, after collecting a large number of N. battus populations alongside farm management data from commercial farms, we explored the prevalence of genetic mutations associated with BZ-resistance (n = 253 farms), the ability of eggs to hatch with and without a chill stimulus (n = 90 farms) and how farm management practices varied throughout the UK (n = 187 farms). In the present study, we identify factors which may be acting as drivers, or barriers, to either the development of resistance or the variable hatching behaviour of N. battus eggs. Generalised linear mixed effect models were applied to regress experimental hatching and genotyping data on farm management and additional environmental data. Both variable hatching and resistance development appeared associated with the maintenance of parasite refugia as well as grazing management, particularly reseeding of pasture routinely grazed by young lambs each spring and the practice of set-stocked grazing. Effective quarantine measures were identified as the main protective factor for the development of BZ-resistance whereas set stocked grazing and population bottlenecks, resulting from reseeding heavily contaminated pastures, were risk factors. Spring maximum temperature and other climatic factors were associated with ‘typical’ hatching of eggs following a chill stimulus whilst several management factors were linked with hatching without prior chilling. For example, practices which reduce parasite numbers on pasture (e.g. re-seeding) or restrict availability of hosts (e.g. resting fields), were found to increase the odds of non-chill hatching. Retention of the timing of lambing and infection level of the host within the fitted model indicated that requirement for a chill stimulus prior to hatching may be plastic, perhaps subject to change throughout the grazing season, in response to immune development or parasite density-dependence within the host. Further investigation of the influence of the factors retained within the fitted models, particularly the theme of parasite refugia which was highlighted in relation to both the presence of BZ-resistance alleles and alternative hatching, is required to establish robust, sustainable parasite control and farm management strategies.

Utilization of Stenotrophomonas koreensis and Bacillus amyloliquefaciens for Improving Growth, Reducing Nitrogen Fertilization and Controlling Bipolaris sorokiniana in Wheat

Wheat (<em>Triticum aestivum</em> L.), a vital cereal, faces significant challenges from common root rot and spot blotch diseases caused by <em>Bipolaris sorokiniana</em>. This study aimed to explore the potential of plant growth promoting rhizobacteria (PGPR) to enhance wheat growth, reduce fertilizer input, and combat <em>Bipolaris </em>diseases. Two PGPR isolates, selected for their superior antagonistic properties, were identified as <em>Stenotrophomonas koreensis</em> RB11 and <em>Bacillus amyloliquefaciens </em>RB12. These PGPR strains displayed multiple plant growth promoting and biocontrol attributes, including phosphate solubilization, indole-3-acetic acid production, nitrogen fixation and antagonism against <em>B. sorokiniana</em> and other fungi. Wheat seed priming with the PGPR significantly improved germination, plant growth, nutrient content and biomass carbon accumulation in the rhizosphere soil. Importantly, the application of RB11 and RB12 allowed for a 25% and 50% reduction in nitrogen fertilizer usage, respectively, without compromising the yield. RB11 and RB12 also demonstrated potent inhibitory effects on <em>B. sorokiniana</em> conidial germination and significantly controlled common root rot and spot blotch in wheat, similar to those observed with the fungicide Protaf 250EC. Overall, this study underscores the multifaceted roles of <em>S. koreensis</em> RB11 and <em>B. amyloliquefaciens</em> RB12 in promoting wheat growth, reducing fertilizer inputs and effectively suppressing wheat pathogens. These findings contribute to the development of PGPR-based strategies for sustainable crop production and disease control.

Characterization of Bacillus amyloliquefaciens BA-4 and its biocontrol potential against Fusarium-related apple replant disease.

Apple replant disease (ARD), caused by Fusarium pathogens, is a formidable threat to the renewal of apple varieties in China, necessitating the development of effective and sustainable control strategies. In this study, the bacterial strain BA-4 was isolated from the rhizosphere soil of healthy apple trees in a replanted orchard, demonstrating a broad-spectrum antifungal activity against five crucial apple fungal pathogens. Based on its morphology, physiological and biochemical traits, utilization of carbon sources, and Gram stain, strain BA-4 was tentatively identified as Bacillus amyloliquefaciens. Phylogenetic analysis using 16S rDNA and gyrB genes conclusively identified BA-4 as B. amyloliquefaciens. In-depth investigations into B. amyloliquefaciens BA-4 revealed that the strain possesses the capacity to could secrete cell wall degrading enzymes (protease and cellulase), produce molecules analogous to indole-3-acetic acid (IAA) and siderophores, and solubilize phosphorus and potassium. The diverse attributes observed in B. amyloliquefaciens BA-4 underscore its potential as a versatile microorganism with multifaceted benefits for both plant well-being and soil fertility. The extracellular metabolites produced by BA-4 displayed a robust inhibitory effect on Fusarium hyphal growth and spore germination, inducing irregular swelling, atrophy, and abnormal branching of fungal hyphae. In greenhouse experiments, BA-4 markedly reduced the disease index of Fusarium-related ARD, exhibiting protective and therapeutic efficiencies exceeding 80% and 50%, respectively. Moreover, BA-4 demonstrated plant-promoting abilities on both bean and Malus robusta Rehd. (MR) seedlings, leading to increased plant height and primary root length. Field experiments further validated the biocontrol effectiveness of BA-4, demonstrating its ability to mitigate ARD symptoms in MR seedlings with a notable 33.34% reduction in mortality rate and improved biomass. Additionally, BA-4 demonstrates robust and stable colonization capabilities in apple rhizosphere soil, particularly within the 10-20 cm soil layer, which indicates that it has long-term effectiveness potential in field conditions. Overall, B. amyloliquefaciens BA-4 emerges as a promising biocontrol agent with broad-spectrum antagonistic capabilities, positive effects on plant growth, and strong colonization abilities for the sustainable management of ARD in apple cultivation.

Functional analysis of a down-regulated transcription factor-SoxNeuroA gene involved in the acaricidal mechanism of scopoletin against spider mites.

Insight into the mode of action of plant-derived acaricides will help in the development of sustainable control strategies for mite pests. Scopoletin, a promising plant-derived bioactive compound, displays prominent acaricidal activity against Tetranychus cinnabarinus. The transcription factor SoxNeuroA plays a vital role in maintaining calcium ion (Ca2+ ) homeostasis. Down-regulation of SoxNeuroA gene expression occurs in scopoletin-exposed mites, but the functional role of this gene remains unknown. A SoxNeuroA gene from T. cinnabarinus (TcSoxNeuroA) was first cloned and identified. Reverse transcription polymerase chain reaction (RT-PCR), quantitative real-time polymerase chain reaction (qPCR), and Western blotting assays all confirmed that the gene expression and protein levels of TcSoxNeuroA were significantly reduced under scopoletin exposure. Furthermore, RNA interference silencing of the weakly expressed SoxNeuroA gene significantly enhanced the susceptibility of mites to scopoletin, suggesting that the acaricidal mechanism of scopoletin was mediated by the weakly expressed SoxNeuroA gene. Additionally, yeast one-hybrid (Y1H) and dual-luciferase reporter assays revealed that TcSoxNeuroA was a repressor of Orai1 Ca2+ channel gene transcription, and the key binding sequence was ATCAAAG (positions -361 to -368 of the Orai1 promoter). Importantly, site-directed mutagenesis and microscale thermophoresis assays further indicated that ASP185, ARG189, and LYS217, which were key predicted hydrogen-bonding sites in the molecular docking model, may be the vital binding sites for scopoletin in TcSoxNeuroA. These results demonstrate that the acaricidal mechanism of scopoletin involves inhibition of the transcription factor SoxNeuroA, thus inducing the activation of the Orai1 Ca2+ channel, eventually leading to Ca2+ overload and lethality. Elucidation of the transcription factor-targeted mechanism for this potent plant-derived acaricide has vital implications for the design of next-generation green acaricides with novel targets. © 2023 Society of Chemical Industry.

Genetic diversity of broomrape (Orobanche cumana Wallr.) populations from different geographical origins assessed by ISSR markers

Abstract The present study was focused on the assessment of genetic diversity in twenty-three populations of Orobanche cumana parasitizing on sunflower in Bulgaria, Turkey, Moldova and Romania using 13 ISSR markers. The obtained results on the genetic diversity parameters showed that the broomrape populations were characterised by a significant level of the intrapopulation diversity. In addition, descriptive population genetic statistics revealed that Turkish populations had a higher level of genetic diversity indices than populations from several areas of the northeast and east of the Balkan Peninsula included in Eastern Europe. The analysis of molecular variance showed that 38 % of the genetic variability was due to differences within populations, 34 % was due to differences among populations and the lowest molecular variation was among countries (28 %). According to clustering and PCA methods, Moldavian, Bulgarian and Romanian broomrapes shared more genetic traits with each other than with Turkish populations within a main gene pool. As a whole, all results of this study showed that there is a high intrapopulation diversity of the O. cumana gene pool in the Black Sea basin. From the clustering and PCA analyses, it can be concluded that the grouping of broomrape populations is partly determined by their geographical origin, as well as by the genetic differences and similarities accumulated over time, and is not related to virulence. The information obtained from this study may be highly relevant in contributing to the development of sustainable control strategies of the pathogen and breeding programmes for sunflower resistance to broomrape.

Review of water quality index models as river quality evaluation tool: insight from various rivers in Indonesia

As industrial activities grow and increase, it is directly proportional to the wastewater produced, which is disposed of into the river. One of the calculation models commonly used for evaluating surface water quality is the water quality index (WQI). The method produces uncertainty in the conversion and is site specific dependent. The data collected for the last five years used a comparative method to assess the status classification of those rivers’ quality. In addition, this study also aims to classify the river quality status and evaluate the WQI model in determining the impact of industrial activities on Sumatra Island and Kalimantan Island, the five longest rivers in Indonesia. This paper uses the WQI to review the water quality condition of Indonesia’s five longest rivers, i.e., Kapuas River, Mahakam River, Barito River, Batanghari River, and Musi River, where the community heavily uses these rivers for their daily needs. This review study concluded that the WQI of a river could vary depending on the measurement data used in calculating the WQI value. The data describing the WQI of a river is a momentary WQI or periodic WQI. The study is expected to be used as a basis for developing a sustainable water pollution control strategy to maintain the grade status of a river according to its classification.