Effects Of Fungicides And Plant Elicitors On Pathogens Of Anthracnose In Camellia Oleifera

Colletotrichum gloeosporioides is is the causal agent of Camellia anthracnose.It mainly harms the leaves and fruits of Camellia oleifera,seriously affects the healthy growth of C.oleifera,and causes significant economic losses.The activity of plant activators and fungicides against C.anthracnose was studied in the study,in order to provide theoretical support for green control of C.anthracnose,and provide a method for "reducing drugs and increasing efficiency" in pest control.The results are as follows.1.According to the sequence analysis of ribosomal transcription spacer ITS,the Camellia oleifera planting base in Shiwuli Village,Changshan County,Quzhou City,Zhejiang Province was preliminarily identified.The pathogenic bacteria of C.oleifera anthrax were two kinds of bacteria,specifically including gloeosporioides f.sp.Camelliae and C.fructicola.2.C.gloeosporioides f.sp.Camelliae was selected as the test pathogen in vitro leaf method was used,and the induced activity of five plant disease resistance activators(salicylic acid,brassinolide,methyl jasmonate,jinggangmycin and benzothiadiazole)against the pathogen of C.oleifera anthracnose was determined.Salicylic acid has the best inducing effect,and the best concentration is 150 mg/L.The induced resistance of salicylic acid to the pathogenic bacteria of C.anthracnose can last for 15-20 days,and the induced resistance effect is the highest at 59.55% on the 6th day after salicylic acid treatment.The conidia of C.gloeosporioides were inoculated on the C.oleifera plant without injury on the second day after salicylic acid was sprayed on the C.oleifera slices.The electron microscope observation showed that the conidia of the pathogenic bacteria germinated abnormally 24 hours later.3.The leaves of C.oleifera seedlings were treated with 150 mg/L salicylic acid spray for 1,2,4,6,10,15 and 20 days,and the changes of various physiological indexes in the leaves were treated.Soluble protein,superoxide dismutase and peroxidase in leaves increased over a period of time.At the peak,the content of soluble protein was1.87 times of CK,the activity of peroxidase dismutase was 1.93 times of CK,and the activity of peroxidase was 4.64 times of CK,all of which showed a downward trend.During the test period,the activities of soluble protein,superoxide dismutase and peroxidase in salicylic acid treatment group were significantly higher than those in CK4.The effects of 7 fungicides on C.gloeosporioides toxicity of C.gloeosporioides f.sp.Camelliae were measured by mycelium growth inhibition method and spore germination inhibition method.Among them,prochloraz has the strongest inhibitory activity on mycelial growth,and EC50 is 0.129 mg/L.Prochloraz had the highest inhibitory activity on spore germination,and EC50 was 43.852 mg/L.Salicylic acid and prochloraz were synergistically compounded.When the ratio of salicylic acid and prochloraz was 1:2,the inhibition rate on the growth of the mycelia of C.oleifera anthracnose was 68.41%,and the synergetic ratio was 1.32,showing obvious synergism.The induced disease resistance of five plant disease resistance activators to C.oleifera was studied.It was found that salicylic acid had the strongest induction activity at 150 mg/L.Soluble protein,superoxide dismutase and peroxidase of oil tea leaves increased after salicylic acid treatment.The combination of salicylic acid and prochloraz has significant synergistic effect.This study provides a basis for green control of C.anthracnose.