GIS-Based Spatial Variability Of Soil Mycoflora In Chengdu Plain

54 soil samples located by GPS (Global Position System) were collected from surface layer with grid and stratum sampling approaches in Chengdu Plain.Soil fungi were isolated and identified by traditional methods. The regional spatial variability of soil mycoflora were performed by the software ArcGIS8.l which combined geographic information system with geostatistics method. The correlations between soil factors and mycoflora were studied.16 fungal genera were identified from surface soil in Chengdu Plain.They were Penicilium spp., Fusarium spp., Acremonium spp., Trichoderma spp., Myrothecium spp., Aspergilus spp., Gliocladium spp., Verticillium spp.,Curvularia spp. Stachybotrys spp.Alternaria spp.fhoma spp. Coniothyrium spp.,Mucor spp.,Chaetomium spp.and Emericellopsis spp.Among 16 genera, Penicilium spp.Jrichoderma spp.JPhoma spp.fusarium spp.and Acremonium spp.were isolated more frequently at 100%,79.6%,75.9%,61.1% and 53.7% in these samples, respectively. Penicilium was the dominat species,and the propotion of quantity was 37.0%.Ten Trichoderma aggregate species were identified from the region.They were T. hamhtum, T. koningii, T. viride, T. citrinoviride,T. album,T. aureoviredeT. pseudokoningii,T.harzianum, T.atrovirede.and T. longibrachiatum.More species of Trichoderma appeared in southwest and middle of Chengdu Plain. T. hamhtum was the most dominant species among Trichoderma population.Based on GIS and geostatistics, mycoflora in Chengdu Plain existed certain auto-correlation in a given spatial range. In some given spatial range, quantity of Fusarium spp., Acremonium spp., Myrothecium spp.and Mucor spp. had significant auto-correlation whereas Penicilium spp., Phoma spp. and T.hamhtum had secondary auto-correlation in spatial distribution,but the spatial auto-correlation of quantity and sort of Trichoderma was low.All species diversity indexes of soil fungi and Trichoderma had distinct spatial variability characteristics. The region of the highest value of species richness existed from Jinyuan to Xindu county, and from that as center the value reduced towards the south and the north, respectively. The spatial distribution of diversity index was similar to that of equality index, and the region of the highest index existed in border between Dayi and Chongzhou appeared with belt, and the data decreased gradually from west to east from the highest value center. Dominance index had the opposite spatial distribution compared with diversity index.The spatial distribution of species diversity of Trichoderma had complicated characteristicsbecause of different environment of soil.The spatial distribution of soil fungi quantity reduced gradually from the northeast to the southwest .The quantity of dominant species had different distribution characters.The study dealt with the relationship between mycoflora and soil factors. The species diversity of soil fungi was distinctly affected by pH. The quantity of soil fungi was limited by pH and available potassium, and the quantity increased gradually with the decrease of pH and addition of available potassium content.Among the main species, available potassium content had significant correlation with the quantity of Penicilium spp., Fusarium spp.Acremonium spp.and Mucor spp., and the quantity would increase gradually with the addition of available potassium. There were significant correlation between pH and quantity of Penicilium spp. Mucor spp. and Myrothecium spp.,and the quantity of them would increase gradually with the reduction of pH. Available phosphorus and quantity of Mucor spp.had significant correlation, and the quantity would increase gradually with the augment of available phosphorus content.