Etiology Of Main Fungal Diseases Of Polygonum Capitatum In Shibing County

It has a long history of production and application of traditional Chinese medicinal materials in Guizhou province.And the huge demand of Polygonum capitatum medicinal value was increased year by year.The planting area of Polygonum capitatum has reached 20.9 hectares in Shibing county.Due to the planting area is increasing,the diseases of Polygonum capitatum has aggravated.The diseases seriously influenced the production and quality of P.capitatum.The P.capitatum diseases control has become the urgent problems in production.Our results mainly include: investigate the disease and Pathogens identified of P.capitatum;determine biological characteristics of Pathogen and to know the infection process of the Pathogen P.capitatum the change of the cell-wall degradation enzymes in this process to provides certain references for solving the pathogen problems of P.capitatum.The main achievements are as the following.1,Investigation of the fungal diseases and the pathogens identification of P.capitatumOn April to November 2016 we have got ring spot and stem wilt about P.capitatum at Niudachang,Shuangjing,Chengguan town in Shibing county,based on the Koch’s Rule as the pathogenic fungi.Through the analysis of pathogen morphological characteristics and DNA sequence,the P.capitatum rings spot was caused by a new species Pilidiella guizhouensis.The P.capitatum stem wilt was caused by Fusarium equiseti.2,Biological characteristics of Pilidiella guizhouensis and Fusarium equisetiThe biological characteristics test was conducted.The results showed that the P.guizhouensis’ s optimal medium was PDA,optimal carbon and nitrogen sources were lactose and glycine,respectively.And the optimum growth temperature was 27℃ and favorable p H value was 7.The F.equiseti’s optimal medium was OMA,optimal carbon and nitrogen sources were fructose and sodium nitrate.And the mycelia was not sensitive to light with the optimum growth temperature was 28℃ and favorable p H value was 7.Both of the mycelia were not sensitive to light.And both of the lethaltemperature for mycelia growth were 65℃ for 10 minutes3,The cell-wall degradation enzymes of pathogens and their role in the pathogenesis.After inoculating P.capitatum leaves and stems with mycelium of P.guizhouensis and F.equiseti,samples were collected from inoculated leaves and stems at different timing intervals.the results of mensurating cell-wall degradation enzymes at six interval times after inoculation showed the 4 cell-wall degradation enzymes(Cx,PG,PE,PMG).them were enhanced compared with CK.in leaves and stems the activity of PG and PMG had been increased by 4 timescompared with CK at 48 h.about Cx the maximal activity from 36 h.and then descended.The maximal activity of the PE was 36 h,48h in P.capitatum leaves and stems.Therefore PG and PMG play a key role in the process of pathogens infection and host cells breakage.