荒漠生境下双网无梗囊霉(Acaulospora bireticulata)的遗传特征

为了阐明荒漠生境下双网无梗囊霉(Acaulospora bireticulata)的遗传多样性,2010年7月从河北省与内蒙古交界处选择多伦、黑城子、二羊点、元上都和正蓝旗5个样地,按0～50cm土层分别采集柠条锦鸡儿(Caragana korshinskii)、沙蒿(Artemisia sphaerocephala)、羊柴(Hedysalum leave)和沙柳(Salix psammophila)等4种植物根围土壤样品.研究了AM真菌与土壤因子和宿主植物的相互关系.对不同样地各个宿主植物双网无梗囊霉进行了RAPD(random amplified polymorphic DNA)分析,每个菌株都出现了1 000,540,480bp条带;进一步测得了18S到28S间的DNA片段序列,进行序列比对后,不同菌株间遗传距离最大只有0.008,DNA序列间无显著差异,存在的碱基差异主要出现在28S区域.发现土壤因子和宿主植物对双网无梗囊霉遗传特征无明显影响.说明双网无梗囊霉分布具有广谱性.

Genetic characteristics of Acaulospora bireticulata in desert zone

In order to elucidate the genetic diversity of Acaulospora bireticulata in desert zone,in July 2010,the soil samples were collected from a depth of 50 cm in the rhizosphere of Caragana korshinskii,Artemisia sphaerocephala,Hedysalum leave and Salix psammophila in five sampling sites including Duolun lake,Heichengzi,Eryangdian,Yuanshangdu and Zhenglanqi in the desert zone of Hebei province and Inner Mongolia north China.This study focused on the relationship of AM fungi with soil factors and with host plants.RAPD was also carried out in this study,which showed that all the strains had similar bands including 1 000,540,480 bp.The DNA fragment from 18 S to 28 S was sequenced by using primers S1 and S2.The results showed that there were no obvious sequence differences among different strains;differences in DNA base were mainly appeared in 28 S;the soil factors and host plants had no significant effects on the genetic characteristics of A.bireticulata strains.The distribution of A.bireticulata strain had a broad spectrum.