Allelopathy Comparison Between Castanea Mollissima And C. Dentata

Castanea mollissima and C. dentata are typical chestnut species which possess rich nutritive value in Asiaand North America, respectively. They play important roles in the ecology and economy in their existing forestecosystems. Chestnut blight has caused catastrophic losses of C. dentata populations since1904. Scientists havetried to make use of blight resistance of C. dentata to help the recovery of C. mollissima population in NorthAmerica.Some scientists point allelopathy has an effect on succession and regeneration of plant communities. Itbecomes especially important to understand the difference of chemical ecology characteristics between C. dentataand C. mollissima. Using germination vigor and rate as seed germination parameters and radicle, plumuleelongation and fresh weight change of seedling as seedling growth parameters, we studied the effect of waterextract of C. mollissima leaves on dicotyledons lettuce, radish and cucumber and monocotyledons onion, rice andwheat. We compared the allelopathic intensity of water extract and11elution components that were separated byX-5macroporous resins from water extract of C. mollissima and C. dentata. The results were as following:1. When the concentration of water extract of C. mollissima leaves is0.5mg·mL-1, it significantly inhibitedgermination of lettuce, radish and onion; when10mg·mL-1, inhibited germination of cucumber, rice and wheat.When0.5mg·mL-1, inhibited radicles growth of lettuce, radish, onion, rice and wheat seedlings and was notsignificant on plumule growth. This result suggested that C. mollissima leaves possessed selective allelopathy.2. The difference of effect of water extract on lettuce, radish, onion and rice seed germination and seedlinggrowth between C. mollissima and C. dentata leaves was not significant, and suggested the allelopathy of C.mollissima and C. dentata were similar.3.7:3,6:4and5:5elution fractions of C. mollissima and C. dentata significantly inhibited seed germinationand seedling growth of lettuce, radish, onion and rice，suggesting that the allelochemicals of C. mollissima and C.dentata extracts are in7:3,6:4and5:5elution fractions.7:3,6:4and5:5elution fractions of C. mollissima and C.dentata concluded the component of t=3.7min according to liquid chromatography. It could be speculated thatthe allelochemicals of C. mollissima and C. dentata might be same substance.