Study On The Inoculation Method And Resistance Identification Of Fusarium Ear Rot In Maize

Maize ear rot,also known as spike grain rot,is a common seed disease in maize.In recent years,with varieties,corn straw returned and technology popularization of change,the increase of planting density,the occurrence of maize ear rot seriously increases,the yield loss caused by the disease and the pathogen toxin complete serious threats to product safety,thus strengthening the comprehensive prevention and control research of maize ear rot is very important.This research adopts the way of field experiment,studying the effects of different inoculation methods,inoculation time,and inoculum size on the incidence of maize ear rot,to provide reference for the improvement of identification techniques for maize ear rot resistance,at the same time,To identify the ear rot disease resistance.the test results are as follows:(1)The six strains of Fusarium graminearum Schw.,Fusarium verticillioides,and Fusarium proliferatum were identified using segregation.Inoculation of Zhengdan 958 and Beiqing 210 revealed that six strains all caused corn ear rot disease,of which F.graminearum had the strongest pathogenicity,and its highest disease index was 58.52,The pathogenicity of F.verticillioides and F.proliferatum was not significantly different.(2)Further clarification of the inoculation method,the inoculation time and the inoculum size of pathogens are the key factors affecting the occurrence of corn ear rot.The effects of silk channel injection method,middle ear injection method,mid-ear toothpick method,and silk channel toothpick method on the degree of morbidity were compared.Among them,the middle ear injection method was the most serious,followed by the silk channel injection method,the mid-ear toothpick method,and the silk channel toothpick method.Comprehensive evaluation of the best method for the identification of corn ear rot variety resistance is silk channel injection method.The earlier inoculation after corn silking was more severe,and the severity of inoculation on the 12 th day after silking was greatly reduced compared with the 4th day after silking.The severity of corn ear rot increased with the inoculation of pathogenic bacteria.When the concentration of pathogenic suspension was 5×10 5 /ml,2 ml per panicle was the appropriate inoculum size for identification of resistance.(3)Among the 193 introduced maize varieties tested,42 varieties,such as jinrui 88 and zhenghong 8,showed high resistance(HR),accounting for 21.76% of the total tested maize varieties.81 varieties,such as liyu 619,yu nong 6 and huayu 777,showed disease resistance(R),accounting for 41.97% of the total tested varieties.Among the 49 varieties of yanke 158 and baodan 8,medium resistance(MR)accounted for 25.39% of the total tested varieties.19 varieties,including shihai 836,longping 206 and ji yu 19,presented senile disease(S),accounting for 9.80% of the total tested varieties.Quan Yin 226 and quan yu 1233 showed high sensitivity(HS),accounting for 1.04% of the total tested varieties.Among the 24 displayed maize varieties tested,7 varieties,such as xidan 68 and chuangyu 358,showed high resistance(HR),accounting for 29.17% of the total tested maize varieties.12 varieties of decca 638 and chulla 368 showed disease resistance(R),accounting for 50.00% of the total tested varieties.Five varieties,such as xiannong 102 and beiqing 340,showed moderate resistance(MR),accounting for 20.83% of the total tested varieties.