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A methacrylate monolith was prepared inside a fused silica capillary column by microwave irradiation using an ionic liquid (1-hexyl-3-methylimidazolium tetrafluoroborate) as the porogenic solvent. Baseline separation of the model analytes, including thiourea, benzene, toluene, ethylbenzene and propylbenzene, was achieved by capillary liquid chromatography, with the lowest theoretical plate height of 26.83 µm for benzene. In addition, we also investigated the effects of the acetonitrile content in the mobile phase, flow rate on retention time, resolution and total porosity. The morphology of methacrylate monolith was studied by scanning electron microscopy.

[ Objective ]The effects of metolachlor on biological characters and yield of rice were studied to find out the main factors for yield reduction and provide references for screening high-tolerant rice varieties and safety application of metolachlor in the paddy field. [ Method ] Laboratory experiment combined with field experiment were used to measure the indexes including the germination rate, shoot height, taproot length, fresh weight, tiller number, grain number, seed setting rate and 1000-grain weight of T227 among the different treatments. [ Result ]The results showed metolachlor had obvious effects on germination rate, grain number and seed setting rate and moderate effects on seedling height, taproot length, fresh weight, tiller number and yield. The germination rate reduced with the increasing of chemical concentration. The germinated rate was 45.6% of the control when metolachlor was applied at the concentration of 2.0000 g/L. Low concentration like 0.025 mg/L metolachlor suppressed seedling growth but promoted the growth of root length and fresh weight. Compared with the control, the seedling height, taproot length and fresh weight was down by 5.7%, up by 4.1% and up by 9.5%. However,the rate was 9.6%, 28.1% and 30.9% when concentration of metolachlor increased to 2.000 mg/L in agar medium. In field experiment, the grain number, seed setting rate and yield was the lowest when the dosage of metolachlor was 315 g per ha . The yield was 7723 kg/ha, down by 17.8% over the control. [ Conclusion ]The whole period of rice growth was affected by metolachlor, however, seed setting rate and grain number of tillers are the main factors leading to yield reduction. [ABSTRACT FROM AUTHOR]

Diamondback moth, Plutella xylostella (L.) is one of the most serious insect pests for its remarkable ability to develop resistance to virtually every insecticide that has been used against it. In the present study, amplified fragment length polymorphism (AFLP) is used to study the genetic differentiation as well as the effects of abamectin-selection on population genetic differentiation for P. xylostella. A dendrogram was constructed from the matrix of genetic distances using the STATISTICA software (Version 4.5) and unweighted pair-group method with arithmetic averages (UPGMA). The data demonstrated that compared to the susceptible strain (ABM-s), the heterozygosity in the abamectin-resistant strain (ABM-r) decreased with the increased selection pressure and resistant level. When the resistance ratio was below 4.3, there was no significant differentiation at the genome DNA level. When the resistance ratio reached 5.8, a fairly significant differentiation began to appear, and when the resistance ratio reached and exceeded 8.1, there appeared a significant genetic differentiation. The results suggest that abamectin selection is associated with increased genetic polymorphism in P. xylostella. [ABSTRACT FROM AUTHOR]

The effects of exogenous methyl jasmonate (MeJA) on the resistance levels to quinclorac and endogenous hormone levels were examined using the resistant and sensitive biotypes of barnyardgrass with the same genetic background. The results showed that exogenous MeJA could significantly increase the resistance of resistant plants to quinclorac, but did not affect the resistance of sensitive plants. There were significant differences in the contents of indole-3-acetic acid (IAA), abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA) among the tested materials. Quinclorac treatment could significantly increase the contents of ABA, SA, and JA in barnyardgrass, with stronger increase of ABA and JA contents in the sensitive plants. Exogenous MeJA could significantly enhance the induction of ABA and JA contents by quinclorac, especially in the sensitive biotypes. These results showed that rapid hormone variations in sensitive plants inhibited their response to herbicide, while gentle hormone variations endowed resistant plants with a strong adapta-bility to herbicide, which closely related to the enhanced resistance by MeJA. ABA and JA hormone signals might play an important role in the resistance of barnyardgrass to quinclorac stress.