Preliminary Studies On The Nematode In The Rhizosphere Of Cryptomeria Fortunei

Cryptomeria fortunei is an important tree species for timber in the south of China,which is fast-growth,good-intensity,vertical-stripe,rniddle-structure,lissome-quality, easy-dryness,better-paint, good-viscosity, hard-erosion,and abroad -distribution.Cryptomeria fortune has a very good consumption,used in construction,buses,furniture and curve .However, parasitic nematodes of plant are important in plant disease,can harm the plant which are lodged,spread virue,bacterium and fungi.take part in plant disease,make plant decline and aggravate plant disease.But studyes on nematode of Aryptomeria fortunei are minority.In view of this, aimed at the weak research points, this thesis adopts basic methods of plant nematology, forest pathology and community ecology, in which species and distribution,the decipline of strcture, time and space, the effect of factor on population of nematode and of nematode on plant,the corralaction between the number of species and the disease in Cryptomeria fortunei, in the nematode in the rhizosphere of Cryptomeria fortunei, are studied, provide some theoretical bases for ecological and synthetic control of the disease,production of Aryptomeria fortunei. The main results are as follows:l.The species of nematode in the rhizosphere of Cryptomeria fortunei: Through isolating and culturing, 12 genus and 14 species were founded from rhizosphere of Cryptomeria fortunei, The species are Tylenchorhynchusniidus,Tylenchorhynchus martini, Helicotylenchus exallus,Helicotylenchus Dihystera.Rotylenchus caudnphusmidiusjciphinema americanum, Apholenchus avenae, Aphelenchoides composticola, Tylenchus platycephalus, Paratylenchus minuts linford, Trichdorus obscurus, Longidorus sp,Macroposthonia sp, Rotylenchulus renformis .These are first founded in Fujian province and have been understood the species of the nematode in the rhizosphere of Cryptomeria fortunei.2.The community constitution and diversity measurement predominant species in the rhizosphere of Cryptomeria fortunei: Through isolating .identification and statistics,One species is different from another, embodied mutual relationship of nematode and its environment.Also predominant species are different in the station of glean.The predominant species of mixed planation is Helicotylenchus.exallus, occupied 43.89 per cent of the totale amount.The predominant species in station fl is Aphelenchoides composticola,,occupied 31.57 per cent of the totale. amount.And The predominant species in station LLJ is Helicotylenchus.exalhts, ccupied 31.55 per cent of the totale.The diversity measurement of community is different in the station of nematode gathering, Mixed planation is more than pure planation.And The diversity measurement of pure planation is big than nursery of Cryptomeria fortunei. The diversity measurement of community changes with a season fluctuation. The summit is in February,The second is in January,third, December.3. The vertical distribution of the community in the rhizosphere of Cryptomeria fortunei: It is proved that the vertical distribution of the nematode community is different in different year old of tree ,slop trend,position and soil fiber. The predominant distribution of young and old forest is in 21-40 centimetre.The percnt of young trees is 47.6,old trees,50.3.The nematode amount in 0-20 centimetre is little,low than middle year forestry.The distribution of the nematode is deep.The number in 0-20 centimetre is 40.0 percent, 21-40 centimetre,48.2.The percent of young and old forest is big than middle year forestry.It is proved that the vertical distribution of the nematode community is different in different soil fiber.In the middle soil and light soil ,the nematode can distribute in soil deep than 100 cm.However,in sandy soil,there is no nematode in 80cm..In the light soil , vertical distribution of the nematode is wide,which the percent is hight than that of the middle soil and sandy soil.in 61~80cm..It is shown that the vertical distribution of the nematode community is different in varying slop trend. In solar slop,the p...