Study On Spatial Distribution Pattern Of The Nematode-trapping Fungus In Western Yunnan On A Watershed Perspective

Objective:To study the spatial distribution patterns of microorganisms.We study the nematode-trapping fungus.And we illustrate the spatial distribution patterns of microorganisms with the nematode-trapping fungus.Methods:1 According to the characteristics of altitude,longitude and latitude.We design our sample points.And we selects 29 sample points in Nujiang watershed and Irrawaddy River watershed in western Yunnan.2 We collect samples in March.3 We collect 10 samples of soil in each sample point.And every sample point we according to “soil in river”,“soil near the river”,“soil in front of joint”,“soil behind of joint”.4 We separate,culture and authenticate the nematode-trapping fungus.5 We compare the diversity and relevance ratio on nematode-trapping fungus.And we combine the environmental conditions to make space clustering figure.Then we use bayesian theory to draw phylogenetic tree on nematode-trapping fungus.Results:In large scales,A.brochopaga is just found in Irrawaddy River watershed.A.superba is just found in Nujiang watershed.In small scales,A.brochopaga and M.sphaeroides are found in Longchuan River watershed.M.eudermatum is found inDaying River watershed.In different longitudes,Arthrobotrys are significant difference in detection rate except A.vermicola.In different latitudes,latitudes and Shannon-wiener diversity index are related.y=5.583-0.178 x,r=-0.526,P<0.05.latitudes and Simpson diversity index are related too.y=2.181-0.062 x,r=-0.511,P<0.05.In three relative elevation gradients,we found A.conoides,A.oligospora,M.thaumasium are significant difference in detection rates.In addition to A.vermicola,all the Arthrobotrys' detection rates have significant difference on main stream and tributary in all study area.Monacrosporium' detection rates are no significant difference.In middle scale,the detection rate of nematode-trapping fungus at main stream and tributary in Nujiang watershed,which detection rates are difference except M.thaumasium.In small scale,Irrawaddy River watershed's first and second tributary are difference in species.A.oligospora has significant difference in number.The greater gap between two neighboring sample points,the smaller similarity about nematode-trapping fungus.The diversity indexes in main stream and tributary are different.In main stream,we find the similarities are smaller.In tributary,we find the similarities are greater than main stream.And in main stream,the neighboring sample points' similarities are smaller than tributary.In land nematode-trapping fungus' species and quantity are greater than in river.The nematode-trapping fungus' species and quantity are the smallest in downstream.Phylogenetic tree shows that some A.oligospora's genes branch all found in land,and some all found in river.What's more,some A.oligospora's genes branch both in land and river.A.oligospora has certain affinity under different scales,which the samples with topological attribute.Conclusions:Geographical isolation is still one of the important factors which influence spatial distribution.In different scales,the species and numbers of nematode-trapping fungus are dynamic changes in main stream.And the species and numbers of nematode-trapping fungus are enrichment in tributary.Nematode-trapping fungus liveboth on land and in water,which dynamic changes in each places.And nematode-trapping fungus travel through the water.They may be affected by factors such as rainfall,temperature,water flow.Under different scales on a watershed perspective,study on distribution pattern of the microorganisms,is reasonable and preferable.