摘要
按30 m的梯度将海拔2 880～3 360 m分为16个采样点,在同一海拔高度按照"Z"字形取样,共取5个点,对16个采样点的土样混匀后以根残体分离法在镰刀菌选择性培养基上进行分离,对分离得到的镰刀菌菌落进行纯化和单孢分离后,以形态学为基础,参照Nelson分类系统进行鉴定.结果表明:在分离到的212个镰刀菌菌株中,有5个菌株为三线镰孢(Fusarium tricinctum).随机选取2株三线镰孢菌株进行β-tubulin基因序列分析,将PCR产物回收测序后在Genbank上比对,菌株TZh-4-3-7和TZh-11-5-2与GenBank上登记的6个新西兰菌株的亲缘关系最近,同源性达96%.利用DNAStar软件绘制其系统发育树状图,结果显示,菌株TZh-4-3-7和TZh-11-5-2与以上6个F.tricinctum菌株均位于系统发育树的同一分支,聚为一类.本研究采用的β-tubulin基因序列分析结果验证了利用形态学鉴定镰刀菌的准确性;将β-tubulin基因序列分析应用于三线镰孢的鉴定中,拓宽了鉴定途径,提高了鉴定的准确性;并了解了三线镰孢在天祝高寒草原不同海拔高度的分布,丰富了我国草原镰刀菌资源库,为进一步探讨镰刀菌与草原退化的关系奠定了基础.
In order to know the distribution of Fusarium tricinctum in Tianzhu Alpine Grassland in Gansu,China,rhizosphere soils around gramineous grass were sampled through a zigzag way from 16 sampling sites at 30 m interval at a elevation ranging between 2 880～3 360 m,5 sub-samples in total were picked up from each sampling site,and root debris from the soils was plated on Fusarium specific medium.The Fusarium colonies were purified and single-spored.Based on the morphological characteristics of Fusarium isolates,and according to the references related to Nelson’s Fusarium taxonomical system,212 Fusarium isolates were obtained and 5 of them were identified belonging to F.tricinctum.Two F.tricinctum isolates of the 5 were randomly selected for sequences analysis of β-tubulin gene.The PCR product of the two isolates were collected,purified,and sequenced.The sequences were aligned in GenBank.It was showed that there was a very close relationship of isolates TZh-4-3-7 and TZh-11-5-2 with the 6 F.tricinctum isolates in New Zealand,and their max similarity was 96%.Microsoft DNAStar was used to draw the phylogenetic tree of isolates TZh-4-3-7 and TZh-11-5-2.The tree showed that both TZh-4-3-7 and TZh-11-5-2 were in the same cluster as the 6 New Zealand isolates.The sequence analysis of β-tubulin gene determined the morphological identification of the 5 F.tricinctum isolates in this study,and the analysis was used to identify F.tricinctum for the first time in China.This study would enrich the future research on grassland degeneration associated with Fusarium.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2011年第1期51-56,共6页
Chinese Journal of Applied and Environmental Biology
基金
甘肃省科学事业费项目(甘科计[2001]21号)
甘肃省教育厅项目(No.032-08)
甘肃农业大学科技创新基金(No.GAU-CX0504)资助~~
