With Polygonatum cirrhifolium root as the donator, the wheat, cucumber and carrot as receiver plant, the potential allelopathic effects of petroleum extracts, acetic ether extracts, n-butanol extracts and aqueous extracts from donator on the seed germination and seedling growth of three receiver plants were studied by culture plate and filter-paper. The results showed that every extracts had different allelopathic effection on different receiver plant or on different position of same receiver plant. The allelopathy intensity were related to the concentration and strengthen along with the concentration raise. The different receiver plant had distinct sensitive to the the allelopathic effect, cucumber was more sensitive than carrot and wheat. Every extracts had inhibition against seed germination and seedling growth, but inhibited root growth at high concentration and stimulated it at low concentration. In a word, every extracts had more impact on the seedling growth, however, had weak inhibition against seed germination. The average allelopathic effection of acetic ether extracts was more stronger, then n-butanol extracts, aqueous extracts and petroleum extracts. The acetic ether extracts had extremely strong inhibition on the growth of seedling and root, and n-butanol extracts on the seed germination also, which implied the Polygonatum cirrhifolium contained the allelochemicals with high polarity. In rhizosphere soil of P. cirrhifolium , the root and seedlings growth of wheat was stimulated, while cucumber and carrot was inhibited.
