Latest ArticlesTo elucidate the control effect of the rice metabolite betaine on rice blast and its resistance-inducing mechanism, exogenous betaine sprays at different concentrations and time points were applied to assess the resistance of rice cultivars against rice blast. The optimal concentration and timing for exogenous betaine application were screened. Furthermore, transcriptome sequencing was performed on rice treated with betaine under the optimal application conditions to analyze its resistance induction mechanism. The results showed that exogenous application of betaine effectively reduced the severity of rice blast in the susceptible rice varieties Huangkenuo and Lijiangxintuanheigu. The optimal relative control effect (40.06%) was achieved with a pretreatment of 20 mmol/L betaine applied 24 hours before inoculation with Magnaporthe oryzae. Transcriptome analysis of rice leaves pretreated with betaine indicated that differentially expressed genes were significantly enriched in the phenylpropanoid biosynthesis pathway at 0, 24, and 48 hours. This treatment also induced the expression of lignin synthesis-related genes, including OsCCR17, OsCCR14, OsPAL3, OsCOMT15, OsCAD2, and the peroxidase gene OsPOX1. Additionally, lignin content and the activities of peroxidase and superoxide dismutase were significantly increased. These findings suggest that betaine induces the expression of genes involved in lignin synthesis and antioxidant enzymes, promotes lignin accumulation, and enhances antioxidant enzyme activity, thereby improving systemic resistance in rice against rice blast.
To effectively prevent and control peanut pod rot, samples showing typical symptoms were collected from Qinghe Town, Tongliao City, Inner Mongolia. The pathogens were isolated and purified using the single-spore isolation method. The obtained strains were identified with morphological and molecular biological techniques, and the toxicities of ten fungicides from succinate dehydrogenase inhibitor (SDHI), quinone outside inhibitor (QoI), and demethylation inhibitor (DMI) against dominant pathogens were determined, fungicides with high toxicity were further determined for their efficacy. A total of 11 fungal strains were obtained via single-spore isolation. Morphological and molecular identification revealed that three strains were identified as Fusarium solani and eight as Botrytis cinerea, accounting for 27.27% and 72.73%, respectively. Botrytis cinerea was the predominant pathogen (with average disease severity indices of 55.09 for peanut pods and 12.50 for peanut kernels). Among SDHI, QoI, and DMI fungicides, benzovindiflupyr, pyraclostrobin, and mefentrifluconazole exhibited the highest inhibition rates against B. cinerea. In vitro tissue experiments revealed that the protective efficacy of 100 mg/L mefentrifluconazole, pyraclostrobin, and benzovindiflupyr against peanut pod rot was 60.16%, 76.42%, and 65.85%, respectively; their corresponding curative efficacy was 58.54%, 81.30%, and 68.29%, respectively. These results were comparable to those of the reference fungicide procymidone. The results showed that mefentrifluconazole, pyraclostrobin, and benzovindiflupyr could be used to prevent and control peanut pod rot.
To investigate the population structure and phylogenetic relationships among different geographic populations of Asiatic rice borer Chilo suppressalis in Ningbo City, China,whole-genome resequencing was performed on 37 individuals from eight populations (six from Ningbo, one from Beijing, and one from Hangzhou). Genomic variations were identified, and population genetic analyses including population structure, selective sweeps, genetic diversity, and historical effective population size were conducted. The results showed that a total of 42 149 215 single nucleotide polymorphisms and 11 912 812 insertions/deletions were identified across the 37 genomes, with most variations located in intergenic and intronic regions. Among the six Ningbo populations, Yinzhou, Yuyao and Haishu populations were closely related, whereas the Xiangshan population showed the greatest genetic distance from the other Ningbo populations and exhibited moderate genetic differentiation. Genes within the selective sweep regions of the Xiangshan population was significantly enriched in seven signaling pathways, including melanogenesis and circadian entrainment. Among the Ningbo populations, nucleotide diversity was relatively higher in the Haishu and Yinzhou populations, but lower in the Xiangshan and Fenghua populations. The Ningbo populations experienced a rapid contraction approximately 3 000—1 000 years ago, followed by a rapid population expansion.
To screen microbial resources for the control of tomato late blight caused by pathogen Phytophthora infestans, strains with strong antagonistic activity were isolated from soil using the plate confrontation method. Their taxonomic status was determined using integrating morphological, physiological, and biochemical characteristics, combined with the 16S rDNA gene sequence analysis. The antifungal activity, action mechanisms, and control effect of the antagonistic strains were investigated via the mycelial growth inhibition method, spore germination assay, and pot experiment. The results showed that a total of 11 strains exhibited antagonistic activities against P. infestans. Among these antagonistic strains, strain C-21 exhibited the highest mycelial growth inhibition rate of 84.41%, and it was identified as Streptomyces flavogriseus. This strain could produce extracellular enzymes including cellulase, protease and amylase. Its fermentation broth could disrupt the mycelial morphology and cell membrane integrity of P. infestans, and significantly inhibited spore germination and zoospore release, with inhibition rates of 69.31% and 57.94%, respectively. The preventive and curative control effects of strain C-21 against tomato late blight were 43.57% and 59.28%, respectively. These findings indicated that strain C-21 had an excellent control effect on tomato late blight, and exhibited promising biocontrol potential for further development and application.
To clarify the potential suitable habitats of Moroccan locust Dociostaurus maroccanus, which was first recorded in June 2025 in Huocheng County, Ili Kazakh Autonomous Prefecture, Xinjiang Uygur Autonomous Region (hereafter Xinjiang), global occurrence data and environmental variables were used to predict its potential distribution in Xinjiang using the MaxEnt model under current climatic conditions and three future climate scenarios, namely SSP126 (low forcing), SSP245 (moderate forcing), and SSP585 (high forcing). The results showed that annual mean temperature, isothermality, minimum temperature of coldest month, mean temperature the driest quarter, mean temperature of the coldest quarter, precipitation of the warmest quarter, land cover classification system, and elevation were the key environmental variables affecting the distribution of D. maroccanus. Under current climatic conditions, potential suitable habitats of D. maroccanus were distributed throughout Xinjiang, with a total area of 80.98×104 km2, accounting for 48.78% of the total area of Xinjiang. High suitable areas were predominantly located in the Ili Kazakh Autonomous Prefecture. By 2061—2080, the potential suitable habitats of D. maroccanus in Xinjiang are projected to expand outward overall, and the area of highly suitable habitats is expected to increase by 85.71%, 181.95%, and 224.44% under SSP126, SSP245, and SSP585 scenarios, respectively. These studies indicate that the risk of establishment of D. maroccanus in Xinjiang, China, is extremely high, and a scientific and efficient early warning, monitoring, and risk management system is urgently needed.
To identify the pathogens causing grapevine root rot in Ningxia Hui Autonomous Region (hereinafter referred to as Ningxia) and to explore indigenous antagonistic microorganisms for developing biocontrol agents, grapevine samples with root rot symptoms were collected from representative winery vineyards in five cities and counties of Ningxia. The pathogens were identified through isolation, identification and pathogenicity tests. Using the more virulent pathogens as indicator strains and the wine grape cultivar Cabernet Sauvignon as the experimental material, the biocontrol efficacy of bacteria isolated from the rhizosphere soil of healthy grapevines was evaluated through plate confrontation assays, mycelial growth inhibition tests and pot experiments. The results showed that the pathogens causing grapevine root rot in Ningxia were Fusarium acuminatum, Fusarium solani, Rhizoctonia solani, Neofusicoccum parvum and Lasiodiplodia theobromae, among which R. solani, N. parvum and L. theobromae are new records as pathogens of grapevine root rot. Fusarium acuminatum, R. solani, N. parvum and L. theobromae exhibited stronger pathogenicity. A total of 62 bacterial and actinomycete strains with distinct colony morphologies were isolated from the rhizosphere soil of healthy grapevines, and four strains exhibiting over 60% inhibitory activity against all four highly pathogenic fungi were selected, namely Bacillus velezensis, Streptomyces alfalfae, Amycolatopsis orientalis and Streptomyces griseus. Among these, the 10.0% sterile culture filtrate of B. velezensis exhibited the strongest inhibitory effect against the four pathogens tested, with inhibition rates ranging from 80.56% to 84.65%, and its volatile compounds exhibited the strongest inhibitory effect against L. theobromae, with an inhibition rate of 73.67%. The three antagonistic actinomycetes showed differential inhibitory effects against different pathogens. Inoculation with the four antagonistic strains via wounded root irrigation inhibited grapevine root rot to varying degrees and promoted an increase in root branch number, indicating that these four antagonistic strains exhibit significant growth-promoting and disease-suppressing effects and possess potential for development as biocontrol agents against grape root rot.
To systematically investigate the differences in predation capacity and control efficiency of predatory ladybirds against aphids under different conditions, laboratory experiments were conducted to evaluate predation at different aphid densities, environmental temperatures, and predator density gradients. The data were fitted with Holling’s disc equation and models of interference and competition. The results showed that the functional responses of Harmonia axyridis to Aphis gossypii, Aphis glycines, Aphis sophoricola, and Chaitophorus populeti all conformed to Holling type II functional response. Among the tested aphid species, H. axyridis exhibited the strongest predation capacity and control efficiency against C. populeti, with a theoretical maximum daily predation of 500.00 individuals, whereas its control efficiency against A. sophoricola was the weakest, with a theoretical maximum daily predation of only 90.91 individuals. The predation capacity of H. axyridis against A. glycines increased with temperature within the range of 21-33 ℃ and reached a maximum at 33 ℃, after which it declined at higher temperatures. Moreover, the fourth-instar larvae of H. axyridis exhibited higher control efficiency against A. glycines than adult females. Increasing predator density intensified intraspecific competition in H. axyridis populations; although total predation increased, the mean predation per individual decreased significantly with increasing predator density, indicating that predation efficiency was constrained by density-dependent interference. Compared with H. axyridis, Adonia variegata showed stronger predation capacity against A. sophoricola. With increasing aphid density, the searching efficiency of both species declined. These results indicate that predatory ladybirds have strong predation potential against aphids, and their functional responses and predation efficiencies are influenced by aphid species, temperature, and the intensity of intraspecific competition, with notable differences among ladybird species.