Changes in peroxidase and phenols activity in apple fruit inoculated with antagonistic Pseudomonas fluorescens isolates and Botrytis mali

The biocontrol activity of three isolates of Pseudomonas fluorescens against gray mold of apple fruit caused by Botrytis mali and their ability to induce biochemical defense response in apple tissue were investigated. Apple fruit (Malus domestica) wounds were inoculated with 20 microL bacterial suspension (10(8) CFU mL(-1)) of Pseudomonas fluorescens followed 24 h later by 20 microL of conidial suspension of B. mali (10(5) conidia mL(-1)). The apples were then incubated at 20 degrees C for 11 days. Lesion diameters were evaluated 6 and 10 days after pathogen inoculation. In addition to controlling gray mold, these three isolates of P. fluorescens caused increase in peroxidase activities that reached maximum levels 2-6 days after pathogen inoculation. Phenolic accumulation was increased in apple fruit treated with antagonists and inoculated with B. mali and exhibited the highest level 6-8 days after treatment. The ability of P. fluorescens to increase activities of peroxidase and levels of phenol compounds maybe one of mechanism responsible its biocontrol activity.     

New Alkaloids from the Mediterranean Sponge Hamigera hamigera

The Mediterranean sponge Hamigera hamigera (family Anchinoideae) was studied since its total extract showed deterrent activity in a fish feeding assay. Eight compounds were isolated from the biologically active fractions and four of these proved to be new natural products, hamigeroxalamic acid (1), hamigeramine (2), hamigeramide (3) and hamiguanosinol (5). The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry.     

鸡Apo VLDLⅡ基因内含子Ⅰ的多态性研究

本研究根据鸡Apo VLDL-Ⅱ基因内含子Ⅰ的基因序列设计3对引物,分别采用PCR-RFLP、PCR-SSCP技术对文昌鸡、如皋黄鸡、丝羽乌骨鸡、安卡肉鸡及红色原鸡5个鸡种进行多态性研究。结果表明,鸡Apo VLDL-Ⅱ基因内含子Ⅰ存在4处突变,分别为:1950处G/A、2522处A/C、2705处A/C及2793处C/T。统计结果显示:安卡肉鸡基因型频率的分布与如皋黄鸡、红色原鸡存在显著差异,文昌鸡基因型频率的分布与乌骨鸡差异不显著,除安卡肉鸡外所有鸡种均处于Hardy-Weinberg平衡状态。