Isolation,Identification Of Pathogen And Control Technique On Oat Anthracnose Caused By Colletotrichum Cereale

Oat anthracnose is one of the main diseases on oats,mainly affecting the leaves,leaf sheaths,stems,and spikelets,causing premature plant aging and poor grain filling,greatly affecting the quality and yield of oats.There is relatively little research on oat anthracnose,and the types of pathogenic fungi are still unclear.Effective prevention and control measures are still lacking in production.The experiment investigated the occurrence of anthracnose in the main planting areas of oats,isolated pathogenic fungi,identified oat varieties resistant to anthracnose,screened efficient fungicides,and studied the effects of sowing time and density on the occurrence of anthracnose.The aim was to provide safe and efficient prevention and control techniques for oat anthracnose.The main research results are as follows:1.An investigation was conducted on the occurrence and harm of oat anthracnose in16 areas of 7 provinces,including Inner Mongolia,Qinghai,Jilin,Heilongjiang,Hebei,Shanxi,and Yunnan.The results showed that anthracnose occurred to varying degrees in various oat planting areas,with the more severe areas being Hohhot Wuchuan,Shanxi Youyu,Ulanqabu Jining,Xinghe,and Chayouqian.2.162 strains of fungi were isolated from oat anthracnose samples from 16 locations in 7 provinces,all of which could cause disease in detached oat leaves.50 strains were selected for live plant inoculation,and the most pathogenic strains were WC-6,WC-8,HLGR-1,HLGR-12,and HLGR-8.Morphological identification results show that conidia are single celled,crescent or spindle shaped,with sharp tips and colorless;The conidial disk has a large number of black needle like bristles;Conidia and hyphae produce oval or nearly circular black adherent cells,which can form a closed capsule when cultured on SNA for about 15 days.Based on molecular biology results,162 strains of fungi were identified as oat anthracnose C.cereale.3.Light is beneficial for the growth of pathogenic hyphae,while darkness is beneficial for the production of conidia by pathogenic fungi;The optimal temperature for mycelium growth and spore production of pathogenic fungi is 25 ℃,the optimal temperature for spore germination is 28℃,the lethal temperature for mycelium is 51℃,10 min,and the lethal temperature for molecular spores is 55℃,10 min;The optimal p H for mycelium growth is 6.When p H is 8,the pathogen reaches its maximum spore production,and the optimal p H for spore germination is 7;The most suitable carbon source for growth is glucose,and yeast is the most suitable nitrogen source for growth.4.Baiyan No.2,Bayou No.14,and Neiyan No.5 showed high resistance and stable disease resistance;Bayan No.7(Naked),Bayan No.5(Naked),Bayou No.18,Bayou No.5,Bayou No.3,and Mengsiyan No.1 showed moderate resistance.Among them,Bayou No.14,Bayan No.7(Naked),Bayou No.3,and Mengsiyan No.1 have higher yields.The ones that show high sensitivity are Qinghai Tian,Qinghai 444,and Dingyou No.4.5.Planting in the surrounding areas of Hohhot in mid to late May will reduce the occurrence of anthrax and result in higher yields;The treatment with a sowing row spacing of 20 cm resulted in a lighter incidence of disease and the highest yield.6.Carbendazim 50% WP,tebuconazole 43% SC,difenoconazole 10% WG,prochloraz 45% EW and azoxystrobin 25% SC had strong inhibitory effects on mycelial growth;azoxystrobin 25% SC,carbendazim 50% WP,dimethoxy-propiconazole 19%ME and mancozeb 80% WP had strong inhibitory effects on spore germination of C.cereale.The better effects of fungicide seed dressing on controlling anthracnose are tebuconazole,difenoconazole,and prochloraz;The effective fungicides for controlling anthracnose by foliar spraying include prochloraz,tebuconazole,and difenoconazole.The control effect of foliar spraying with fungicides is higher than that of seed dressing.Spraying tebuconazole and prochloraz on the leaves has the best net benefits.Spraying tebuconazole and prochloraz on the leaves during the booting stage of oats has good effects and significant benefits in preventing and controlling oat anthracnose.