土壤有机质含量和酸碱度对烟草内生真菌生物多样性的影响

Effects of Soil Organic Matter Contents and pH Values on Biodiversity of Tobacco Endophytic Fungi

为研究环境生态因素对烟草内生真菌的影响,在湖北省恩施州选取不同有机质含量和酸碱度的田块,以云烟87为供试植株,探究土壤有机质含量和酸碱度对烟草内生真菌生物多样性的影响。试验分别选取6块不同有机质含量(分别为16.3,20.7,23.3,27.1,31.4和35.6 g/kg)及4块不同pH(分别为4.3,5.5,6.4和7.6)的田块,采用五点取样法采集健康烟草植株,分离纯化根中内生真菌并根据r DNA-ITS序列分析进行菌种鉴定,以Shannon多样性指数及相对分离频率反映内生真菌生物多样性。结果发现,烟草内生真菌生物多样性随土壤有机质含量的升高呈先上升后下降的趋势,在6个不同土壤有机质含量下,内生真菌Shannon多样性指数分别为0.53、0.67、0.82、1.09、0.86和0.59;而烟草内生真菌生物多样性随土壤pH的升高呈下降的趋势,在4个不同土壤pH下,内生真菌Shannon多样性指数分别为1.36、1.12、0.93和0.83。研究表明,土壤有机质含量和酸碱度会对烟草内生真菌生物多样性产生一定影响。在一定范围内,土壤有机质含量的升高或者pH的降低可以增加烟草内生真菌的物种丰富度。

To explore the effects of environmental ecological factors on biodiversity of endophytic fungi,the tobacco growing areas of Enshi prefecture,Hubei province with different organic matter contents and pH values were selected.In this experiment,6 fields with organic matter contents of 16.3,20.7,23.3,27.1,31.4,and 35.6 g/kg,respectively,and 4 fields with pH values of 4.3,5.5,6.4,and 7.6 respectively,were chosen.The endophytic fungi,which colonized in the inner root of tobacco,were isolated and identified with morphological characteristics and rDNA-ITS sequences.Shannon index(H’)and Relative frequency(RF)were used to reflect biodiversity and distribution of the tobacco endophytic fungi.The results indicated that biodiversity of endophytic fungi increased firstly and then decreased with the increase of soil organic matter contents,and the Shannon diversity index were 0.53,0.67,0.82,1.09,0.86,and 0.59,respectively under 6 organic matter contents levels.While biodiversity of endophytic fungi decreased with the increase of pH values,and the Shannon diversity index were 1.36,1.12,0.93,and 0.83,respectively.We concluded that the increase of soil organic matter contents or the decrease of pH values can increase the richness of tobacco endophytic fungi in a certain range.