Allelopathic Effects Of Fallen Leaves Of Actinidia Deliciosa And Diospyros Kaki In Agroforestry System

The objectives were to probe into the strength of allelopathy and allelopathic mechanism from fallen leaves of Actinidia deliciosa and Diospyros kaki, and explore the potential allelopathy of the leaf litter decomposing liquid with decomposing time change. Taking A. deliciosa and D. kaki, as Brassica napus, Lacluca saliva var. angustana, Brassica rapavar. chinensis, Triticum aestivum, Vigna radiata as receptor plants, allelopathy effects of different concentrations of aqueous extracts from fallen leaves and litter of A. deliciosa and D. kaki on different crops were investigated. The tested indices included bioassay and allelopathic mechanism. The researches were to make sure which receptor plant had stronger resistance, and to put forward better models for agroforestry system.The results are as follows:(1) The aqueous extracts of A. deliciosa inhibited seed germination positively and extended the time of seed germination of B. napus, L. sativa var. angustana, B. rapa var. chinensis. The results showed that seeds germination and seedling growth of receptor crops increased at lower concentrations (0.001g/ml) of A deliciosa leaves aqueous extracts, and those items decreased at higher concentration (0.04～0.08g/ml). L. sativa var. angustana is the the most sensitive crop. The activity of SOD of three receptor crops increased firstly then decreased as the concentration of extracts increased. The content of MDA increased in these seedlings compared with these checks.(2) A. deliciosa’s leaf litter decomposing liquid extended the time of seed germination of B, napus. L. sativa var. angustana, B. rapa var. chinensis. The germination rate was little restrained. A. deliciosa’s leaf litter decomposing liquid of different decomposition stages had significant inhibitory effects on seed germination. The inhibition synthesis effects of different decomposition stages on seed germination were-157.32,-102.16,-12.87. The results showed that inhibition effects were decreased with the decomposition time prolonged. The decomposing liquid of different decomposition stages had significant inhibitory effects on root length and plant height. The inhibition synthesis effect of different decomposition stages on seedling growth were-31.53,-28.09.69.57. With the decomposition time prolonged. the inhibition decreased and changed into stimulating effects. The seed germination of L. saliva var. anguslana was little restrained. The seedling growth of L. sativa var. angustana was remarkablely promoted.(3) Aqueous extracts of fallen leaves D. kaki could prolong the time of seed germination of T. aestivum. V. radiata. B. napus. The germination rate of three receptor seeds was little restrained. The inhibition of aqueous extracts greatly correlated with the extract concentration. Seedling growth of receptor crops increased at lower concentrations (0.001g/ml) of D. kaki leaves aqueous extracts and changed into inhibition effects with the concentration increased. T. aestivum is the the most sensitive crop. Receptors resisted allelopathy stress (>0.04g/ml) by enhancing the activity of SOD. The soluble protein of receptors decreased and the content of MDA increased when the stress level exceeded its tolerance.(4) D. kaki’s leaf litter decomposing liquid of different stages delayed seed germination of T. aestivum, V. radiata, B. napus. The germination rate was little restrained. The inhibition synthesis effects of different decomposition stages on seed germination were-54.04,-26.44,-8.08. The results showed that inhibition effects were decreased with the decomposition time prolonged. The decomposing liquid of different decomposition stages had significant inhibitory effects on rootlength and plant height. The inhibition synthesis effect of different decomposition stages on seedling growth were-23.66,21.07,27.67. The decomposing liquid inhibited three crops’seedling growth after decomposing for one day, but with the decomposition time prolonged, decomposing liquid changed into stimulating effects. The seed germination of V. radiata was little restrained. The seedling growth of V. radiaa was remarkablely promoted.