Pathogen Identification And Pesticides Screening Indoor For Some Diseases Of Glycyrrhiza Uralensis Fisch And Radix Rumicis Japonici

Three new diseases were caused by Phyllostica sophoricola Hollos,Phyllostica polygonorum Saccardo.Pectobacterinm carotovora subsp.atroseptica on Radix Rumicis Japonici and Glycyrriza uralensis Fisch were firstly reported for the world and one disease caused by Erysiphe polygoni DC.on Radix Rumicis Japonici were firstly reported in Jilin province in China.The sympotoms of the four diseases were described in detail and biological characteristics and pesticides-screening indoor on some of pathogens were studied.Glycyrriza uralensis leaf spot.leaves were infected usually a brown spherical spot appeared initially from the edge of the leaves,gradually enlarged as irregular spot.Brown conididium with foramen fromed on both sides of the leaves,56～150μm indiameter,60～120μm high. Conidium oval,colourless,single.Conidia body 4～12×4～8μm.According to the symptoms of the disease and morphology of the pathogens and comparison with concerned species of Phyllosticta,the pathogen was identified as Phyllostica sophoricola Hollos. Radix rumicis Japonici leaf spot.sympotoms mainly appearred on leaves,which greynish-brown with brown borders,spherical or nearly spherical,diameter of 1～4mm or more were observed.brown conidium with foramen fromed on surface of the leaf,90～128μm indiame-ter, 90～120μm high;conidium with two oil ball oval,colorless and single,conidium body 4～8×4～5μm.According to the sympotoms of the disease and morphology of the pathogens and comparison with concerned species of Phyllosticta,the pathogen was identified as Phyllostica polygonorum Saccardo.Radix rumicis Japonici bacterial leaf blight.small black spot initially appeared on leaf at first,with the develop of the disease,turn to a big irregular blight,lastly leaves fall off.The strains were bacilliform,Gram-negative,peritrichous flagella six or more;could infect Dioscorea nipponica;37℃growth negative;5%NaCl growth positive;sucrose reduction positive;potato rot negative;malonic salt negative;gelatin liquefaction positive;indole negative; lecithinase negative;erythromycin sensitivity positive;acided from maltose,lactose,trehalose, melibiose,cellobiose,esculin,levulose,D-galactose,D-gluconate,glycerol,sorbitol,D-mannitol, D-mannose,rhamnose,salicin,sorbite,starch,sucrose and D-xylose;couldn't produce acid from melezitose,a-CH3-D-gluconate,Glycerol and lactose;According to concerned parts of《Berge-y's Manual of Systematic Bacteriology》2nd ed,it confirmed that the disease was caused by Pectobacterinm carotovora subsp.atroseptica(Van Hall 1902)Dye 1969.Radix rumicis powdery.Mycelium spot were observed on bothcides of leaves,lessly on back of the leaves,with the develop of the disease,mycelium spot fradually become as thick or thin powdery spot which can cover all of the leaves and brown-black needly point Cleiseothecium were found in powdery spot,Conidispora colume shaped,(25.0)29.5-30.0 (-48.0)×(10.0-)12.5-16.5(-17.5)μm.Cleistothecium coarctated,lessly scattered,darkbown, flat-sphere shaped,(8-)10-30(-50)appendage with no branch or irregular branches,few 1-2 double-fork branches.Cleitothecium(80-)90-120(-131)μm indiameter,2-5 ascopora,body (17.0-)19.0-32.0(-36.0)×(11.0-)12.0-17.0(17.5)μm.All above four disease,Glycyrriza uralensis Phyllostica leaf spot,Radix rumicis Phyllostica leaf spot,bacterial leaf blight of Radix rumicis were not reported in the world,so Glycyrriza uralensis Fisch and Radix rumicis Japonici,were the new record hosts of their pathogens. Erysiphe polygoni DC.on Radix rumicis was firstly reported in Jilin province,in China.Pesticides were screened for two fungical diseases with methods of inhabition zone and growth rate indoor;The lowest effective concentration and the diameter of inhabition zone of 8 bactericides to bacterial disease were tested indoor.The results showed that the inhabtion rate of Thiram,fungi-bacterial spot king were the highest to Glycyrriza uralensis leaf spot disease, Radix rumicis leaf spot,Streptomycin+Oxyteracykine,Agricultural-Streptomycin was the best effective to inhabit the pathogen,Oxytetracyclinym the lowest effective concentration to inhabit pathogen,so Streptomycin+Oxyteracykine,Oxytetracyclinym,Agricultural-Streptomycin were the preferred bactericides to Radix rumicis bacterial leaf blight for field trial.