3-Methyl-5-（2-methylphenyl）-1,3,4-oxadiazol-2（3H）-one （6） and N,N-diethyl-2-（2- methylbenzoyl）-hydrazinecarboxamide （7） were designed and synthesized from 5-（2-methyl- phenyl）- 1,3,4-oxadiazol-2（3H）-one （5） by substituting and ring-opening, respectively. The target compounds were confirmed by IR, JH NMR spectroscopy, MS, elemental analysis and single-crystal X-ray diffraction. Compound 6 （Cl0Hl0N202, Mr = 190.20） crystallizes in the triclinic system, space group P1 with a = 7.4645（16）, b = 10.868（2）, c = 12.970（3） A, α= 110.542（2）, β= 98.142（2）, γ= 99.766（2）°, V = 947.7（3） A3, Z = 4, F（000） = 400, Dc = 1.333 g/cm3, μ = 0.095 mm-1, the final R = 0.0550 and wR = 0.1483 for 2956 observed reflections with I〉 2σ（1）. Compound 7 （C13HI9N302, Mr = 249.31） crystallizes in the monoclinic system, space group C2/e with a = 18.926（3）, b = 12.1853（17）, e = 14.740（2） A, fl = 125.6380（10）~, V= 2762.7（7） A3, Z = 8, F（000） = 1072, Dc = 1.199 g/cm3,μ = 0.083 mm-1, the final R = 0.0554 and wR = 0.1468 for 2395 observed reflections with I 〉 2σ（I）. The preliminary bioassay results indicate that compound 6 exhibits notable fungicidal activities against Fusarium graminearum, Botrytis cinerea, Rhizoctonia cerealis and Colletotrichum capsici at the concentration of 100 μg/mL.
A total of 479 bacterial strains were isolated from brine （Bohai, Qinhuangdao City, Hebei Province, China）. Bioassay results indicated that 4 strains named Hal, Hal7, Ha38, and Ha384 had herbicidal activity. And strain Hal had the highest effective herbicidal activity. As a result, this study aims to JdentJfy strain Hal, characterize its physiological and biological activities, evaluate the herbicidal activity of its metabolites, and develop a ＇pesta＇ formulation and assess its effectiveness on Digitaria sanguinalis. Hal was identified as Serratia marcescens based on 16S rDNA sequencing. This strain has a flagellum, a diameter of 0.5 to 0.8 IJm, and a length of 0.9 to 2.0 IJm. The indole test shows positive results, and the catalase enzyme exhibits strong positive reactions. Results further showed that the inhibitory concentration （IC50） of the crude extracts to D. sanguinalis radicula and coleoptile were 3.332 and 2.828 mg mL-1, respectively. Both the suppression of D. sanguinalis and the cell viability of the Hal formulation in ＇pesta＇ were higher when stored at 4℃ than at （25＋2）℃. These results indi- cated that S. marcescens Hal can potentially be used as a biocontrol agent against D. sanguinalis.
YANG JuanWANG WeiYANG PengTAO BuYANG ZhengZHANG Li-huiDONG Jin-gao
以玉米品种“郑单958”为材料，在大田条件下，研究了乙烯利（0和180 g hm–2）和氮肥水平（0、75、150和225 kg N hm–2）对夏玉米产量、氮素吸收和利用以及SPAD值的影响。结果表明，乙烯利处理显著降低了氮吸收量和吸收效率，但显著提高氮利用效率，其中乙烯利处理氮农学效率比对照提高了32.7%~34.6%，而且乙烯利处理对玉米产量及其产量构成因素没有显著影响；随着施氮量增加，夏玉米产量、产量构成因素和氮吸收量显著增加，而氮吸收效率、氮利用效率、氮偏生产力和氮农学效率随之降低，其中225 kg N hm–2处理氮吸收量比0 kg N hm–2处理提高了68.4%~91.8%，但225 kg N hm–2和150 kg N hm–2处理之间的氮吸收量差异不显著。乙烯利和氮肥对氮吸收量、氮吸收效率和氮农学效率具有互作效应。喷施乙烯利和增施氮肥均能提高灌浆期穗位叶 SPAD 值，但两者之间没有互作效应。通过相关性分析表明，夏玉米产量与吐丝期氮吸收量、收获期氮吸收量、灌浆期穗位叶SPAD值显著正相关。
Twenty-seven novel pyrrolidine-2,4-dione derivatives containing N-substituted phenylhydrazine moiety were synthesized. Their structures were confirmed by IH NMR, 13C NMR and MS. The half effective concentration （ECs0） values of the title compounds against the phytopathogenic fungi Rhizoctonia cerealis were evaluated. Com- pounds 61 and 6q displayed good bioactivity with EC50 values of 1.626 and 2.043 μg/mL, respectively. The 3D quantitative structure activity relationship（3D-QSAR） model of CoMFA was established with reliable cross-validated correlation coefficient q2 value of 0.585 and Noncross-validated correlation coefficient r2 value of 0.971. This model provided a tool for guiding further design and synthesis of novel pyrrolidine-2,4-dione derivatives with high fungicidal activity.
