Resistance Analysis Of Breeding Lines To Northern Corn Leaf Blight And Identification Of Exserohilum Turcicum Races In Northern Of Heilongjiang Province

Northern corn leaf blight (NCLB),caused by Exserohilum turcicum,which belong todeuteromycotina, also known as the stripe, coal and grain disease, leaf blight, leaf spot disease andso on,is one of the main diseases of maize in China. This desease is harm to leaf, leaf sheath andbract of maize.Severe loss of maize production was caused when NCLB were epidemic, the losswas20%in general year, more than50%when it was serious epidemic. The epidemic of NCLBwas closely related to the resistance of the maize varieties and the variation to pathogenic bacteria.The emergence of new superiority races were often the prelude of the transformation production ofmainmaizecultivars from the resistance phenotype to susceptible phenotype. the most economicand effective way to prevention the NCLB was to find the resistance resources, breed resistantdisease varieties. According to the presumption of gene to gene: explicitlying the type of NCLBraces and distribution frequency, finding new resistan genes and breeding the resistance many kindof diseases varieties could decline the speed of physiological differentiation of NCLB, the numberof pathogen population, do so we could control the NCLB damage. Therefore, to track andidentify the variation of physiological races, and analysis the type of Exserohilum turcicum,combine with monitoring of the cultivars resistance, would facilitate the analysis the outbreak riskof of Exserohilum turcicum, have important significance for breeding resistant disease varieties.1. The disease leaves as separation sample were acquisited from the northern Heilongjiangprovince, the third and fourth accumulated temperature zone, including7counties (city). a total of21maize leaf blight pathogen isolates were received. Conventional differential host identificationtechnology was used to identified and analyzed these samples.13N and23N were identified.ofwhich, Ht3and HtN have the highest virulence frequency,it was100%; the, the second was Ht1,the virulence frequency was66.7%, the lowest toxicity frequency was Ht2, it was33.3%.2.100backbone corn germplasms from the Keshan branch academy were inoculation toidentify the races, the carrier sorghum grains and spray inoculate method were used. The resultwere that the rate was21%of resistant materials to the100backbone corn germplasms, most ofthe material were susceptible. By analyzing the interaction model of host and pathogen races,100maize resource were confirmed that were carrying Ht3, HtN gene.3. In2012,the disease level of most maize varieties was1~3, the individual varieties havereached to3~5through surveying and understanding the NCLB occurance in collecting thedisease leaves; In2013, the disease degree was seriouser than in2012in7counties (city) survey,corn leaf blight disease levels from most of the varieties was3, the individual varieties reached to5~7.