Sensitivity Detection Technique and Resistance Risk Assessment of Magnaporthe grisea to Tricyclazole

In vitro detection method for the sensitivity of Magnaporthe grisea to tricyclazole was studied, and the potential resistance risk of blast disease to tricyclazole was assessed. Both EC50 of hyphal melanization (EC50-H) and minimum inhibitive concentration of melanization in appressorial (MIC-A) by inhibitor tricyclazole showed positive correlation to the EC50 of tricyclazole against blast disease tested in vivo, with relative co-efficiency (R5) of 0.8995 and 0.8244, respectively. However, stability and reproducibility of EC50-H were better than those of MIC-A, suggesting that it could be used to detect the sensitivity of M. grisea to tricyclazole in vitro. Tricyclazole sensitivity of the progenies derived from single spores of the most sensitive isolate DY2 and the least sensitive isolate GY6 detected in sensitivity monitoring in 2000 was not stable, with mean EC50 values of 4.4968 μg/mL and 5.4010 ug/mL, respectively, indicating that the difference in EC50 between DY2 and GY6 was not caused probably by resistance variation. EC50 of GY6 did not increase significantly when continuously selected for twenty generations under the selection pressure of tricyclazole in vivo. However, the sensitivity of DY2 was decreased by 10-fold after selected for twenty generations. The results suggested that tricyclazole was still low resistance risk for M. grisea in China.

Activity of the Fungicide JS399-19 Against Fusarium Head Blight of Wheat and the Risk of Resistance

This report reviews the characteristics of JS399-19, a novel cyanoacrylate fungicide. JS399-19 strongly inhibits the mycelial growth of the fungal plant pathogens of the genus Fusarium and exhibits great potential in controlling Fusarium head blight （FHB） on wheat and other cereals. The mode of action of JS399-19 is evidently different from that of benzimidazole （for example, carbendazim） and other sort of fungicides, making it a possible replacement for carbendazim in China to manage carbendazim-resistant subpopulations of Fusarium graminearum and F. asiaticum. JS399-t9 has excellent protective and curative activity against these pathogens. Incorrect use of this fungicide, however, is likely to select for resistance. Among JS399-19-resistant mutants of F. asiaticum induced in the laboratory, the resistant level of mutants was high and the phenotype of resistance against JS399-19 was conferred by a major gene by genetic analysis. The fitness of laboratory-induced JS399-19-resistant mutants of F. asiaticum was nearly equal to that of their parents. JS399-19 lacks cross resistance with other sort fungicides. To control FHB with JS399-19 and to delay the development of the fungicide-resistance, farmers should use tank mixtures containing JS399-19 and carbendazim, metconazole, tebuconazole, or prothioconazole.

Discussion on Common Problems in Risk Assessment of Lightning Disaster

The problems in calculating parameters of equivalent collection area,earth resistivity and lightning protection category as well as their effects on lightning disaster risk assessment were analyzed,and practical examples proved the effects of those differences on lightning protection identification,intercept efficiency calculation in evaluating lightning disaster risk. In the meantime,several new concepts,such as the height of buildings for lightning protection were defined,and a fixed radius value was set to the ground flash density for calculation,establishing the ground flash density formula to solve the problems in parameter calculation,which would be beneficial to promote the standardization of lightning disaster risk assessment.

The Study on the Correlation Between Plasma Adiponectin Level and Coronary Heart Disease

Objectives To investigate the relationship between plasma adiponectin level and coronary heart disease （CHD）, and some established cardiovascular risk factors and to probe its probable pathogenesis which adiponectin results in CHD. Methods The levels of plasma adiponectin, fasting plasma insulin （FINS）, C-reactive protein （CRP） and P-selectin were measured by ELISA, plasma ET-1 was measured by radioimmunoassay （RIA） in 75 male patients with CHD and 30 healthy male people. Body mass index （BMI）, waist / hip ratio （WHR） and insulin resistance index （Homa-IR） were calculated respectively. Results （1）The plasma adiponectin levels in CHD group were lower compared with control group[（5.18±2.57）mg / L vs（8.94±2.59）mg / L, P〈 0.001 ], there was no significant difference of plasma adiponectin levels in CHD sub-groups （P 〉 0.05）.（2） Based on multinominal stepwise logistic regression analysis, adiponectin was one of significant and independent risk factors for CHD. （3） Multivariate liner stepwise regression analysis showed that adiponectin had significant correlation with BMI and TG, BMI and TG were independent factors influencing on plasma adiponectin levels. （4） Pearson correlation analysis indicated plasma adiponectin levels were inversely related to FINS levels , Homa-IR, CRP, P-selectin and ET-1. Conclusions （ 1 ）Plasma adiponectin levels are lower in CHD patients compared the control subjects, there are no significant difference of plasma adiponectin levels in patients with SAP, UAP and AMI. （2） Plasma adiponectin levels are relative with CHD. Hypoadiponectinemia is an independent risk factor for CHD. （3）Established cardiovascular risk factors such as BMI and TG have an obvious influence on adiponectin. （4）The probable pathogenesis by which adiponectin involves in CHD is suggested that adiponectin relates to insulin resistance, inflammatory reaction and dysfunction of vessel endothelium.

Detection of ryanodine receptor target-site mutations in diamide insecticide-resistant Spodoptera frugiperda in China

Spodoptera frugiperda(Lepidoptera:Noctuidae)is a widely distributed pest of corn.Since it invaded China in 2018,it has caused serious damage to local corn production.Chlorantraniliprole,an anthranilic diamide insecticide,has been widely used to control lepidopteran pests.Tetrachloropyramid is a new allosteric modulator insecticide devel-oped based on chlorantraniliprole,so it has a similar mechanism and insecticidal effect.In this study,we investigated resistance levels to chlorantraniliprole and tetrachloropyramid in S.frugiperda from 13 populations in China.Among the populations tested,the relative highest resistance to chlorantraniliprole occurred in the Guangzhou population,and the most susceptible to chlorantraniliprole was found in the Wuhan population.The lethal dosage LD50 value of the Guangzhou population against chlorantraniliprole was 27.8-fold higher than that of the Wuhan population.Minimal differences were observed among 5".frugiperda populations in terms of sensitivity to tetrachloropyramid.Heterozygous mutations at the 14734 site of the ryanodine receptor(RyR)were found,while no mutations were found in the G4891 site.The mutations were detected in only two of the 786 individuals analyzed one from the Qinzhou population and other from the Anshun population(frequency below 2%in both cases).There were no significant differences in the expression levels of RyR between Guangzhou and Wuhan populations.In summary,our results indicate that:(i)S.frugiperda has low resistance levels to diamide insecticides in China;and(ii)the differences in relative resistance among the 13 populations analyzed are not caused by the mutations in RyR or the expression of RyR.