Study On Allelopathic Of Reguarity Of Casuarina Equisetifolia To Litsea Glutinosa Of Local Tree Specie In Sandy Coast Zone

Casuarina equisetifolia that has more strong adaptation and growth than other tree species in sandy coast zone because of its tolerance to wind、sand、drought and salt is the main tree species of protective forest in south-east in China. The protective forest of Casuarina equisetifolia has more important function to improve ecological environment in coast zone since the protective forest can tolerate some kind of nature disasters such as Typhoon and tide from the ocean. However, stable forest ecological system is consisted of many different tree species while the stand which is made of only tree species is unstable. At present, the stability of the protective forest which is fundamental formed by only Casuarina equisetifolia is bad. Litsea glutinosa is one of the local tree species in south coast in Fujian Province. This tree specie naturally grows in sandy coast and often appears under the stand of Casuarina equisetifolia. Moreover, it grows much good in the site of big density of the stand of Casuarina equisetifolia. It is possible that Casuarina equisetifolia exists some allelochemicals and the ecological environment of under Casuarina equisetifolia promotes the growth of Litsea glutinosa. The study on allelopathy of Casuarina equisetifolia to Litsea glutinosa was carried out through fresh leaf、root and soil in the surrounding root extract of33-year Casuarina equisetifolia as allelochemicals to deal the seedlings of Litsea glutinosa. The allelopathic regularity of Casuarina equisetifolia to Litsea glutinosa was showed by the effective analysis of allelochemicals from Casuarina equisetifolia to the growth、biomass、nutritional absorption、Photosynthetic pigment、cell membrane protective system and AOS metabolism. The study provided the theory base for the breeding of mutual allelopathy of the species of Casuarina equisetifolia and Litsea glutinosa in the building windbreak forest in sandy coast. The main study results were submitted as follows:1.The growth and biomass of leaf, stem and root of Litsea glutinosa seedlings were showed the regularity which they were firstly added and then decreased but more than ck with the increasing of water extract concentration of fresh leaf、root and soil surrounding root from Casuarina equisetifolia. The result showed that the leaf、 root and soil surrounding the root of Casuarina equisetifolia existed the allelochemicals to promote the growth of Litsea glutinosa and the allelochemicals from Casuarina equisetifolia to Litsea glutinosa were emitted through the ways of leaf and root washing.2.The absorption of nutrition of Litsea glutinosa seedlings including N、P、K、 Ca、Mg、Fe、Mn、Cu and Zn was added with the increasing of the water extract concentration of soil surrounding the root of Casuarina equisetifolia. The distributive regularity of N、P、K、Ca、Mg、Fe、Mn、Cu and Zn in Litsea glutinosa seedlings was leaf>stem>root or leaf>root>stem. It showed that the water extract of soil surrounding the root of Casuarina equisetifolia promoted Litsea glutinosa seedlings to absorp the soil nutrition.3.The content of Chla and Car was added with the increasing of the water extract concentration of soil surrounding the root of Casuarina equisetifolia increased. While it was2.3and1.8more than that of Ck when the water extract concentration of soil surrounding the root of Casuarina equisetifolia was200g·kg-1. The content of Chlb was the biggest when the water extract concentration of soil surrounding the root of Casuarina equisetifolia was250g·kg-1. The content of Chla、Chlb and Car reduced when the water extract concentration of soil surrounding the root of Casuarina equisetifolia was more than200g·kg-1and250g·kg-1. But it was still more than that of Ck. 4.The content and accumulation of carbon in leaves、stems and roots of Litsea glutinosa seedlings were increased with the adding of the water extract concentration of soil surrounding the root of Casuarina equisetifolia and the content was the biggest when the water extract concentration was200g·kg-1. The content of carbon in leaves、 stems and roots of Litsea glutinosa seedlings was3.6%、2.4%and2.9%more than that of Ck respectively while the accumulation was80.0%、145.0%and133.8%more than that of Ck respectively. The content and accumulation of carbon in leaves%stems and roots of Litsea glutinosa seedlings reduced while the water extract concentration of soil surrounding the root of Casuarina equisetifolia was more than200g·kg-1, but they were still more than that of Ck.5.The water extract of soil surrounding the root of Casuarina equisetifolia increased the content of soluble total sugar, reducing sugars, sucrose of Litsea glutinosa seedlings. The content of soluble total sugar, reducing sugars, sucrose of Litsea glutinosa seedlings was the biggest when the water extract concentration of soil surrounding the root of Casuarina equisetifolia was200g·kg-1. And the content which was still more than that of Ck slowly reduced while the water extract concentration was more than200g·kg-1.The photosynthetic ability strengthened and the content of carbohydrate and soluble total sugar in Litsea glutinosa seedlings increased since the water extract of soil surrounding the root of Casuarina equisetifolia promoted.6.The content of soluble protein and soluble proline in leaves of Litsea glutinosa seedlings increased with the water extract concentration adding of soil surrounding the root of Casuarina equisetifolia, And these contents reached the biggest when the water extract concentration were200g·kg-1and250g·kg-1. The content of soluble protein and soluble proline in leaves of Litsea glutinosa seedlings slowly dropped while the water extract concentration continued to increase. But they were still far more than that of Ck. The analysis showed that the difference of soluble protein and soluble proline content between the dealing of the water extract concentration of soil surrounding the root of Casuarina equisetifolia and the Ck was obvious. The content of MDA in leaves of Litsea glutinosa seedlings reduced in the environment of the water extract of soil surrounding the root of Casuarina equisetifolia. Which showed that the cell membrane of Litsea glutinosa seedlings was good and the plant grew regularly.7.The activity of CAT, POD, APX, GR, SOD of Litsea glutinosa seedlings which were dealed by the water extract of soil surrounding the root of Casuarina equisetifolia was more than that by pure water. The activity of CAT, POD, SOD of Litsea glutinosa seedlings varied waving in different water extract concentration dealing of soil surrounding the root of Casuarina equisetifolia. While the activity of APX, GR increased with the water extract concentration of soil surrounding the root of Casuarina equisetifolia added. But the O2-producing speed in leaves of seedlings directly dropped with the increasing of the water extract concentration of soil surrounding the root of Casuarina equisetifolia.The study results from above of view indicated that Casuarina equisetifolia could produced allelochemicals through leaves and roots emitting to promote Litsea glutinosa to absorb nutrition from soil and grow, increase the content of Chl and Car, protect cell membrane system. The relation between Casuarina equisetifolia and Litsea glutinosa was harmonious in the stand in sandy coast zone. Accoording to the law of mutual allelopathy between Casuarina equisetifolia and Litsea glutinosa, the species of mutual allelopathy between Casuarina equisetifolia and Litsea glutinosa can be breeded. The planting in sandy coast zone or regeneration of old Casuarina equisetifolia could adopt the mixed way of Casuarina equisetifolia and Litsea glutinosa or planting the Litsea glutinosa under old Casuarina equisetifolia belt.