内蒙古固沙造林树木真菌病害区系

Fungus Disease Flora of Sand Fixation Trees in Inner Mongolia

系统调查了内蒙古固沙造林树木真菌病害状况，采集到罹病树木１６科３７种（属），鉴定出病害１２６种、病原真菌７６种，比较了不同树种及不同组织器官的病害类型和病原生态群落组成的差异。根据沙区不同的水热指标与地理条件，讨论了病原物的生态地理区系，并分为乌兰布和沙漠固沙造林区、毛乌素沙地固沙造林区和科尔沁沙地固沙林区。

Wulan Buh Desert, Mu Us and Horqin Sandy Lands distribute in different zones, where a group of fungus diseases of sand fixation trees adapted to the kinds of trees and the ecological environment are developed. Through the investigation from 1993 to 1996, 37 species (genera), 16 families of trees suffering from diseases and 126 kinds of diseases were collected. And 76 species of plant pathogenic fungi were identified as 3 subdivision 6 class 12 order 15 family, in which Ascomycotina consisted of 2 class 5 order 6 family 15 species, Basidiomycotina had 2 class 3 order 4 family 11 species, Deuteromycotina had 2 class 4 order 5 family 50 species. Pathogenic fungi, according to their parasitized positions are divided into leaf ecological community, branch ecological community and trunk, root and fruit ecological communities. The structure and the size of various community of pathogenic fungi differ greatly. Most kinds occur in leaf ecological community, account for 49 3% of the total, which followed by the branch, the trunk ecological communities in order. Less pathogenic fungi parasitized to root and fruit ecological communities. According to the water and heat conditions of the sand areas and the differences of the distribution of vegetation, and the distribution and occurence of tree fungus diseases, the faunae of the agents could be divided into 3 zones: ①Wulan Buh Sand fixation Forest Zone, there are 36 kinds of fungus diseases, which mainly include canker caused by Cytospora spp., powdery mildew of Haloxylon ammodendron Bunge and Hedysarum scoparium Fisch et Mey. caused by Leveillula saxaouli (Sorok.) Gdov., poplar and willow rust caused by Melampsora , and sooty mould caused by Fumago vagans Pers. ②The Mu Us Sandy Land Sand Fixation Forest Zone, there are 50 kinds of fungus diseases, mainly including canker caused by Cytospora spp., Hedysarum mongolicum Turcz. rust caused by Uromyces spp., Hedysarum scoparium Fisch et Mey rust by Phakopsora sp., Salix psammophila Gordejevii chang et skv. tar spot disease by Melasmia salicina lev., and poplar gray spot by Coryneum populinum Bres. ③The Horqin Sandy Land Sand fixation Forest Zone, there are 40 kinds of fungus diseases, mainly including poplar canker caused by Dothichiza populea Sacc. et Br., Hedysarum mongolicum Turcz. powdery mildew by Leveillula saxaouli (Sorok.) Golov., poplar leaf rust by Melampsora larici populina Kleb., and poplar gray spot by Napicladium asteroma Allesch. In Mu Us Sandy Land where the water condition is superior, the diseases occur mostly in leaf ecological community (63 4%), while in Wulan Buh Desert where the weather is dry and hot, the diseases mainly occur in branch ecological community (39 1%). In Horqin Sandy Land the diseases mainly occur in trunk ecological community (27 6%), as for root and fruit ecological communities there are no remarkable differences among the 3 zones.