The Phylogenetic Research Of Saccharomyces And Three Kinds Of Related Ascomycetous Yeasts Based On Ribosomal DNA ITS-1 Sequences

The paper researched by 24 Saccharomyces cerevisiae strains and three kinds of related ascomycetous yeasts in the Angel Yeast Co.,L td,by electrophoresising and sequencing, ribosomal DNA ITS-1 sequences can analysis their's phylogenetic systematics relationship. The research displayed that yeasts Genus level can be discerned by agarose gel electrophoresis and polyacarylamide gel electrophoresis, but the latter is more advanced. The Saccharomyces cerevisiae strains ITS-1 sequences are most disalike, few of them are equal completely. The bigger differences are part of base pairs about Poly-T, others are exchanged by single base pair. The ITS-1 sequence length are from 360bp to 370 bp, and the percent of G+C is about 35.3%. All the ITS-1 sequences are registered in the GenBank and blusted in the NCBI, which displayed that a single strain is not belong to Saccharomyces cerevisiae. Through analysising sequences and phylogenetic tree, the one which is belong to Saccharomyces uvarum. The phylogenetic tree and systematics analysis the relationship between them by ClustalX1.8, Phylip3.6 rackage. The research dismonstrated that ITS-1 sequence analysis is a realiable, rapid, accuratable classification, which has many important function in ferment production or yeast ferment at yeast company.With shape conventional taxonomy method and so on characteristic observation and physiological biochemistry determination carries on the yeast strain the classified appraisal, generally only can classify to the level which is, moreover spends cycle long, is easy to appear in the taxonomy the confusion, causes the system classification not to be unstable, frequently can give in the production to bring the very big barrier, causes the huge economic loss. In recent years, along with the biochemistry and the molecular biology fast development, some molecular biology methods gradually applied fungus and in the bacterium and so on yeast phylogenetic systematics, thus simplified the past some complex appraisal procedures, enable each kind of mold mushroom spawn systematics status to obtain improves and is clear about, also greatly enhanced in the production application value .