Pathogen Identification,Pathogenic Factors And Control Of Spring Maize Ear Rot Disease In The Northern Region

Maize is the main grain crop in our country,so the status of its food security is beyond doubt.Maize ear and grain can be infected by a variety of fungi making the corn ear mildewing and rotting,so it is called corn ear grain rot.The disease is an important worldwide fungal disease in maize production.Not only will it cause the direct reduction by rotting ear,but also produce a variety of toxic secondary metabolites produced by its pathogenic bacteria which have serious toxic and side effects on human and livestock resulting in the high risk of consumption for its pathogenicity,teratogenicity and carcinogenicity.Meanwhile,the ear rot has a serious effect on postpartum storage and processing.This study identified the dominant strain by separating pothogenic bacteria of ear rot of spring maize in northern alpine region to make clear the pathogenicity related factors and infection cycle path,and find out its pathogenicity correlation with maize stalk rot,corn borer and double spotted leaf nail.This study also proposed the integrated pest management to provide technical support for achieving high yield and high quality maize in northern alpine region of Heilongjiang Province.Here are the results:(1)The pathogen of maize ear rot was identified,and the main pathogens of Maize Ear Rot in northern alpine region were selected as: Fusarium graminearum Schw.;Fusarium moniliforme Sheld.;Cladosporium spp.and Penicillium spp..(2)Artificial inoculation was carried out on the local cultivation of regular varieties and strains to develop the field resistance screening experiments.The incidence of variety,strain and disease index was investigated before the harvest of corn.The Duncan new repolarization difference method was used to analyze the difference significance.Finally,14 resistant strains and varieties were selected.Among them,four varieties,the Xianyu 335,the Lihe 1,the Simon 6 and the Songyu 9,showed high resistance,and the disease grade were respectively 0.3?0.8?0.2 and 0.1.DMY2??DMY2??DK516??XZD2 four parent materials showed higher resistance,and the disease grade were respectively 0.3,0.2,1.1 and 0.5,so they can be used as anti source reserve.(3)Detect the biotoxin in mouldy corn samples by sampling in different places to make omprehensive understanding of the species and content of biological toxins in maize mouldy grains of the northern alpine region.The results showed that maize ear rot was the main cause of biotoxin pollution in maize.(4)The correlation investigation of the incidence of Maize Ear Rot in the field and the stem base rot,disease and insect pests and meteorological factors was detected in Fujin?Hegang?Suihua and other places.Finally the pathogenicity and coefficient were determined by regression analysis.(5)Proposed spring corn ear rot disease prevention measures.The one was the screening test of seed coating agent.The results showed that 35 g/L semen cream suspension seed coating agent and 11% semen methylene pyrimimine suspension seed coating agent can effectively inhibit the pathogen against the seeds,reduce the risk of seedling disease,and play the role of preserving seed and promoting seedlings.The two was to implement the technology of prevention and control forward.Early drug using in the corn jointing period can effectively control the occurrence of spike disease in the later period.