The Quantity And Bacterial Diversity In Strawberry Soil Under Different Cultivation Condition

The quantity and diversity of strawberry soil bacteria under different cultivation condition was tested by traditional culture method and the molecular biology method PCR-DGGE which was widely used in microbial quantity and diversity research.Extracted DNA of the strawberry soil that sampled from Mijiatai and Xuejia village,Honggu area in Lanzhou,Gansu province in China.Then we used PCR-DGGE method to estimate the molecular diversity of the strawberry soil.That suggested these lanes show high similarity,means the predominant bacteria in different strawberry soil were highly similar.There were 133 samples after dilution cultivated from each soil sample,enriched and purified single colony.PCR amplified the extracting DNA and used restriction endonuclease Haeâ…¢digested the amplification,and then compared the result,after that there were 23 sequences successfully obtained by sequencing.The 23 sequences were divided into 7 genuses by the MEGA software,namely:Bacillus firmus, Streptomyces,Firgoribact,Sinorhizobium,Pseudomonas,Chyseobacterium,and Flavobacterium,through built a phylogenetic tree the result suggested that these bacteria existed widely;all of them are extensively growing in the environment; most of them are good for plant growth except the Chryseobacterium and Flavobacterium which were common in clinical specimens,and some species were pathogenic.The main groups were bacillus firmus and Pseudomonas,each of them was accounted for 39.13%.It was suggested that the bacteria from continuous cropping strawberry soil show low diversity than others from rotation cropping strawberry soil by classifying each single colony into 7 genuses.Colony counted result show that the quantity of the bacteria from continuous cropping strawberry soil obviously low.The experiment result suggested that the diversity of bacteria is not high in all sample plots.It might be caused by perennial cultivation condition.It has great influence to crop growth condition that using pesticide and fertilizer improperly. These results suggest that rotation cropping is a reasonable way to maintain the diversity and quantity of soil bacteria to ensure the strawberry production and higher quality.