荒漠柠条锦鸡儿AM真菌多样性

为了阐明荒漠柠条锦鸡儿(Caragana korshinskii Kom.)根围AM真菌群落组成及其分布特点,2010年7月从河北省与内蒙古交界荒漠带选择多伦湖、黑城子和二羊点3个样地,按0—10、10—20、20—30、30—40、40—50 cm 5个土层采集柠条根围土壤样品,研究了柠条根围AM真菌物种组成、生态分布及与土壤因子的相关性。共分离鉴定出4属24种AM真菌,其中球囊霉属(Glomus)16种,是3个样地共同优势属;无梗囊霉属(Acaulospora)5种,是3个样地共有属;盾巨孢囊霉属(Scutellospora)2种;多孢囊霉属(Diversispora)1种;网状球囊霉(G.reticulatum)是黑城子和多伦湖样地优势种,二羊点亚优势种;黑球囊霉(G.melanosporum)是黑城子和二羊点样地优势种,多伦湖亚优势种;二羊点的AM真菌种类和孢子密度最高;黑城子和多伦湖样地无明显差异。AM真菌孢子密度与土壤碱解N、有机质和速效P含量极显著正相关,其中土壤碱解N影响最大。结果表明,柠条根围AM真菌物种多样性丰富,具有明显空间异质性,并与土壤因子关系密切,这为进一步分离筛选优势AM真菌菌种,充分利用AM真菌资源促进荒漠柠条生长提供了依据。

Diversity of arbuscular mycorrhizal fungi in the rhizosphere of Caragana korshinskii Kom. in desert zone

Arbuscular mycorrhizal(AM) fungi play an important role in maintaining the ecosystem function and plant biodiversity in arid lands,and serving as the indispensible factor in the restoration and reestablishment of vegetation.AM fungi are widely distributed in global terrestrial ecosystems and play a bridge role in the cycle of nutrient material between plant and soil.Many studies on the survey of AM fungi resources,ecological distribution,symbiotic relationship and AM fungi related with different environmental factors had been conducted now.Caragana korshinskii Kom.was widely used for vegetation rehabilitation for its high ecological and economic values in China.In addition,it has certain features such as the ability that easy to sprout and forest,rooted deep and the strong resistance to stress.And it also has nodule formation so that can help restore degraded land by atmospheric nitrogen fixation and improve the soil structure and ecological environment.In order to elucidate the diversity and distribution of AM fungi associated with the major desert plant Caragana korshinskii Kom.in desert zone.In July 2010,the soil samples were collected from a depth of 50cm in the rhizosphere of Caragana korshinskii Kom.and were divided into five depth intervals: 0—10,10—20,20—30,30—40,40—50cm in three sampling sites in the desert zone of Hebei and Inner Mongolia province north China including Duolun Lake,Hei Chengzi and Er Yangdian.The annual precipitation,average altitude and coordinate of Duolun Lake were 384.5mm,1312m and N42°11′601″E116°36′870″respectively;of Hei Chengzi were 250-350mm,1321m and N42°09′817″,E115°56′107″;of Er Yangdian were 426mm,1386m and N41°51′095″,E115°47′657″.In this study,24 AM fungal species from four genera were isolated in three sampling sites.In these species,16 species belonged to Glomus,five to Acaulospora,two to Scutellospora and one to Diversispora.Glomus was the dominant genus and Acaulospora was the subdominant genus in the three sampling sites.G.reticulatum was the dominate species in Duolun Lake and Hei Chengzi,and was the subdominant species in Er Yangdian;G.melanosporum was the dominate species in Hei Chengzi and Er Yangdian,and was the subdominant species in Duolun Lake.Spore density of AM fungi in Er Yangdian was the highest,and had no obvious differences between Duolun Lake and Hei Chengzi.Spore density had a significant positive correlation with the available N,soil organic carbon and available P,and the available N was the highest.The results showed that the diversity of AM fungal species was rich in the rhizosphere of Caragana korshinskii Kom.,and they had significant spatial distribution dynamics.The paper described the diversity and distribution of AM fungi in the rhizosphere of Caragana korshinskii Kom.,so that it will provide great help to ecosystem reestablishment,isolation of dominate species and sustainable economic development in desert zone.