[Study on allelopathy effect of pericarp extract of Phellodendron amurense].

Through the study of allelopathy of the pericarp of Phellodendron amurense, the role of self-regeneration barriers was investigated in order to find ways and means for the protection of wild populations of P. amurense. Solution preparation: soaked pericarp of P. amurense in distilled water at 4 degrees C to get solution A, and reflux extraction of pericarp with distilled water at 100 degrees C to get solution B. Both of the solution A and solution B were used in the experiment of seed germination and seedling growth with the seeds of cabbage and wheat. The results showed that 20 g x L(-1) concentration of solution A and solution B inhibited significantly seed germination of cabbage and wheat, while 100 g x L(-1) concentration of solution A even completely inhibited the seed germination of wheat. 20 g x L(-1) concentration of solution A significantly inhibited the cabbage and wheat seedling growth, completely inhibited the root growth of cabbage, while 100 g x L(-1) concentrations of solution A completely inhibited seedling growth of cabbage and wheat. Comparing to solution A, the intensity of solution B are diminished on seed germination and seedling growth. It is concluded that the allelopathy of pericarp of P. amurense is multi-material role in the results, some of allelochemicals are easily degradable when exposed to heat. Overall, the allelopathy of pericarp of P. amurense can affect the seed germination and seedling growth. It is supposed that allelochemicals existed in the pericarp of P. amurense is one of the reason leading to difficulties in self-regeneration of its population.