<正>应用薄层层析?荧光测定法研究了石蒜花期前后鳞茎内源多胺含量的动态变化，分析了内源多胺与石蒜开花的关系。在花芽分化前期鳞茎内3种多胺的浓度是递增的，于6月初达到最大；在花芽分化后期，鳞茎内3种多胺的浓度是递减的。花期腐胺Put和精胺Spm含量迅速下降，并维持在较低水平，但花后展叶期又有明显回升。整个发育过程中以Put的含量最高，变幅较大，而亚精胺Spd含量最少，变幅较小。

Bursaphelenchus xylophilus isolate was inoculated on one-year-old resistant and susceptible seedlings of Pinus thunbergii respectively, and nematode dispersal and water potential were studied thereafter. Results showed that, at the initial stage the number of nematodes was small and nematode dispersal rate was low. Most passing nematodes in resistant seedlings were downwards and the number was distinctly smaller than that in the susceptible. Passing nematodes in a susceptible were both upwards and downwards, and nematode dispersal rate and number of the downwards were significantly smaller than those of the upwards. Later, the nematode dispersal rate rose when nematodes began to propagate. The result of conduction in water potential showed that both the susceptible and the resistant had the same variation in the values, in which they rose first then got down but rose again at last. This study might provide some guides for histopathology studies on pine infected by B. xylophilus.