Time filter

Source Type

Yin Y.,Zhejiang University | Liu X.,Zhejiang University | Shi Z.,Jiangsu Academy of Agricultural Sciences | Ma Z.,Zhejiang University | Ma Z.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects
Pesticide Biochemistry and Physiology | Year: 2010

The benzimidazole fungicide carbendazim (CBD) has been used extensively in China for the control of sclerotinia stem rot (SSR) of rapeseed caused by Sclerotinia sclerotiorum. In this study, 245 isolates of S. sclerotiorum were examined for their sensitivities to CBD, and two resistance levels were identified. Among 245 isolates, 78 isolates were highly resistant to CBD. These CBD highly resistant (CBD-HR) isolates were more sensitive to the phenylcarbamate fungicide diethofencarb than CBD sensitive (CBD-S) isolates. One isolate was medium resistant to CBD, and insensitive to diethofencarb. Random amplified polymorphic DNA (RAPD) analysis showed the CBD-HR isolates had different genetic backgrounds. Analysis of the DNA sequence of the β-tubulin gene showed that all CBD-HR isolates had a point mutation at the codon 198, causing a substitution of glutamic acid to alanine. The CBD medium resistant (CBD-MR) isolate had a point mutation at the codon 200 causing a substitution of phenylalanine to tyrosine. Based on these point mutations, a multiplex allele-specific PCR method was developed to detect two different point mutations simultaneously in single PCR amplification. © 2009 Elsevier Inc. All rights reserved. Source

Liu K.,Zhejiang University | Cao Z.,Zhejiang University | Pan X.,Zhejiang University | Yu Y.,Zhejiang University | Yu Y.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects
Environmental Toxicology and Chemistry | Year: 2012

The phytotoxicity of an herbicide in soil is typically dependent on the soil characteristics. To obtain a comparable value of the concentration that inhibits growth by 50% (IC50), 0.01M CaCl2, excess pore water (EPW) and in situ pore water (IPW) were used to extract the bioavailable fraction of nicosulfuron from five different soils to estimate the nicosulfuron phytotoxicity to corn (Zea mays L.). The results indicated that the phytotoxicity of nicosulfuron in soils to corn depended on the soil type, and the IC50 values calculated based on the amended concentration of nicosulfuron ranged from 0.77 to 9.77mg/kg among the five tested soils. The range of variation in IC50 values for nicosulfuron was smaller when the concentrations of nicosulfuron extracted with 0.01M CaCl2 and EPW were used instead of the amended concentration. No significant difference was observed among the IC50 values calculated from the IPW concentrations of nicosulfuron in the five tested soils, suggesting that the concentration of nicosulfuron in IPW could be used to estimate the phytotoxicity of residual nicosulfuron in soils. © 2012 SETAC. Source

Liu K.,Zhejiang University | Liu K.,Anshun University | Pan X.,Zhejiang University | Han Y.,Zhejiang University | And 3 more authors.
Science of the Total Environment | Year: 2012

Both sorption by soil and uptake by organisms of ionizable organic pollutants depend on their speciation (i.e., neutral and ionized forms); thus, the bioavailability of ionizable organic pollutants is more complicated than that of neutral organic pollutants in soil. The toxicity of the weak base carbendazim to earthworms (Eisenia fetida) was estimated using Soxhlet extracted concentrations (CSE), an excess of water extracted concentrations (CEEW), ex situ pore water concentrations (CEPW) and in situ pore water concentrations (CIPW) in different soils. The results indicated that the median lethal concentrations (LC50) calculated from CSE ranged from 2.32 to 34.0mgkg-1 in the five tested soils and the coefficient of variation (CV) of LC50s was 69.8%. When the LC50 was calculated from the CEEW, CEPW and CIPW, the variability of the LC50 gradually became smaller in these soils, with the CVs of LC50s being 58.1%, 50.6% and 38.6% (for CEEW, CEPW and CIPW, respectively). However, the LC50 based on CIPW in strongly acidic soil (where carbendazim partially exists as ionized form) was significantly lower than in other soils, and the values of the LC50 calculated from the in situ pore water concentrations were approximately equal. The results indicated that the in situ pore water concentration could be used to estimate the toxicity of carbendazim in different soils especially in those soils where carbendazim exists in the neutral form. © 2012 Elsevier B.V. Source

Fang H.,Zhejiang University | Fang H.,Key Laboratory of Molecular Biology of Crop Pathogens and Insects | Dong B.,Zhejiang University | Dong B.,Agricultural Service Center | And 5 more authors.
Journal of Environmental Sciences (China) | Year: 2012

With the development of transgenic crops, there is an increasing concern about the possible adverse effects of their vegetation and residues on soil environmental quality. This study was carried out to evaluate the possible effects of the vegetation of transgenic Bt rice lines Huachi B6 (HC) and TT51 (TT) followed by the return of their straw to the soil on soil enzymes (catalase, urease, neutral phosphatase and invertase), anaerobic respiration activity, microbial utilization of carbon substrates and community structure, under field conditions. The results indicated that the vegetation of the two transgenic rice lines (HC and TT) and return of their straw had few adverse effects on soil enzymes and anaerobic respiration activity compared to their parent and distant parent, although some transient differences were observed. The vegetation and subsequent straw amendment of Bt rice HC and TT did not appear to have a harmful effect on the richness, evenness and community structure of soil microorganisms. No different pattern of impact due to plant species was found between HC and TT. It could be concluded that the vegetation of transgenic Bt rice lines and the return of their straw as organic fertilizer may not alter soil microbe-mediated functions. © 2012 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Source

Bai Y.Y.,Zhejiang University | Bai Y.Y.,Southwest University | Yan R.H.,Southwest University | Ye G.Y.,Zhejiang University | And 5 more authors.
Environmental Entomology | Year: 2010

During 20052008, field studies were conducted at two locations in Chongqing, China, to assess the potential effects of transgenic rice expressing Bacillus thuringiensis (Bt) Cry1Ab protein on the nontarget ground-dwelling collembolan community in three postharvest seasons. Collembolans in non-Bt and Bt rice fields were sampled with pitfall traps during each of two postharvest seasons of 2005/2006 and 2006/2007 and litterbag traps during each of three postharvest seasons of 2005/2006, 2006/2007, and 2007/2008. Ground-dwelling collembolans in rice fields during the postharvest seasons were abundant, whereas community densities varied considerably between the two locations and among the three seasons. A total of 67,310 collembolans, representing three species, Entomobrya griseoolivata, Hypogastrura matura, and Bourletiella christianseni, were captured during the three postharvest seasons. E. griseoolivata was the predominant species, accounting for 87.7% of the total captures, followed by H. matura (10.7%) and B. christianseni (1.6%). In general, there were no significant differences in species compositions and abundances of each species between Bt and non-Bt paddy fields, suggesting no significantly impact of plant residues of Cry1Ab rice on collembolan communities during postharvest seasons. © 2010 Entomological Society of America. Source

Discover hidden collaborations