Identification And Chemical Control Of Main Pathogens Of Atractylodes Chinensis And Polygonatum Sibiricum

Rhizoma Atractylodis and Rhizoma Polygonati are common Chinese herbal medicines in China.The medicinal components of Rhizoma Atractylodis are volatile oil,polysaccharide,volatile oil,atractylodin,etc.,which are often used to eliminate rheumatism such as dampness.The medicinal components of Rhizoma Polygonati are mainly alkaloids,saponins,polysaccharides and flavonoids,which have the effects of tonifying qi and nourishing yin and nourishing the body.At present,there are many pharmacological studies and chemical components of Atractylodes lancea and Polygonatum sibiricum.There are few experiments related to the disease prevention and control of Atractylodes lancea and Polygonatum sibiricum.There are few related studies on the identification of pathogen bacteria of Atractylodes lancea and Polygonatum sibiricum and the research on chemical control.The relationship between pathogen bacteria and Atractylodes lancea and Polygonatum sibiricum is used to explore the causes and control methods of diseases.The relationship between the development of diseases and environmental factors provides reliable technical support for the leaf diseases of Atractylodes lancea and the root diseases of Polygonatum sibiricum in the process of planting,early prevention,diagnosis and control of diseases,so as to achieve standardized production and control of drug quality.The main results of this study are as follows:1.Collection of pathogen bacteria.From 2020 to 2022,a total of 314 strains were isolated from the diseased leaves with typical black spot symptoms of A.chinensis collected from the producing areas of Jilin Province and Liaoning Province,and 286 strains were pathogen by pathogenicity test.Morphological identification combined with molecular biological identification,using the method of multi-gene sequence analysis,a total of 2 species of Alternaria.spp were identified:91 strains of Alternaria tenuissima and 195 strains of Alternaria alternata,accounting for 31.82%and 68.18%respectively.The separation frequency of Alternaria alternate was the highest.It was first reported that A.tenuissima could cause black spot disease of A.chinensis.From 2019 to 2022,a total of 24 Fusarium.spp strains were isolated from the diseased rhizomes with typical root rot symptoms collected from the Polygonatum sibiricum production area of Jilin Province.Through morphological and molecular biological identification,multi-gene sequence analysis was carried out.A total of 2 Fusarium species were identified,including 16 strains of Fusarium solani and 8 strains of Fusarium oxysporum,accounting for 66.67%and 33.33%,respectively.2.Study on the effects of different biological characteristics on the number of spores and mycelial growth of Alternaria spp.and root rot of Atractylodes chinensis.Study on the mycelial growth of two kinds of Atractylodes chinensis.The results showed that Alternaria can grow in the range of p H 4～11,Fusarium can grow in the range of p H 4～11.Alternaria grew fastest under alternating light and dark conditions,and Fusarium grew fastest under light conditions.Alternaria can grow at 10～35°C,and Fusarium can grow at 10～35°C.The lethal temperatures of A.alternata and A.tenuissima were 48°C and 52°C,respectively.The lethal temperatures of F.solani and F.oxysporum were 58°C and 61°C,respectively.The growth rate of Alternaria was the fastest when mannitol and lactose were used as carbon sources,and the growth rate of Fusarium was the fastest when lactose and starch were used as carbon sources.Alternaria grew fastest when potassium nitrate and sodium nitrate were used as nitrogen sources,and Fusarium grew fastest when glycine and potassium nitrate were used as nitrogen sources.Alternaria grew fastest on PDA and V8 medium,and Fusarium grew fastest on PCA and OA medium.The effects of different physical and chemical conditions on the sporulation of black spot disease:the sporulation was the highest in light and dark alternation,the sporulation was the highest in potassium nitrate,the sporulation was the highest in glucose,the sporulation was the highest in V8 medium,and the sporulation was the highest at p H 7.3.Indoor toxicity determination of bacteriostatic effect and inhibition of spore germination.The results of indoor bacteriostatic test showed that for A.alternata AC6-1,the EC₅₀ value of tebuconazole was 0.0003μg·m L^-1,and the EC₉₀ value was 0.0027μg·m L^-1.A.tenuissima AC6-8,fludioxonil had the best inhibitory effect with EC₅₀ value of 0.0003μg·m L^-1 and EC₉₀ value of 0.0188μg·m L^-1.For F.solani HJH,the EC₅₀ value of diethofencarb was 0.0004μg·m L^-1,and the EC₉₀ value was 5.3241μg·m L^-1.The EC₅₀ value of F.oxysporum HJZ and fludioxonil was 0.0002μg·m L^-1,and the EC₉₀ value was 0.0090μg·m L^-1.The spore germination method showed that the EC₅₀ value of fludioxonil was 0.7889μg·m L^-1 and the EC₉₀ value was 5.8883μg·m L^-1 for A.alternata AC6-1.For A.tenuissima AC6-8,the EC₅₀ value of azoxystrobin was 0.0003μg·m L^-1,and the EC₉₀ value was 0.0188μg·m L^-1.For F.solani HJH,the EC₅₀ value of pyrimethanil was 0.0012μg·m L^-1,and the EC₉₀value was 0.1016μg·m L^-1.The EC₅₀ value of F.oxysporum HJZ and fludioxonil was 0.0146μg·m L^-1,and the EC₉₀ value was 1.9842μg·m L^-1.Mycelial dry weight method:For A.alternata AC6-1,the inhibitory effect of fludioxonil was the best,and the mycelial dry weight was less than 0.5 g under the treatment of 100μg·m L^-1.The inhibitory effect of tebuconazole and azoxystrobin on A.tenuissima AC6-8 was the best,and the dry weight of mycelia was less than 0.5 g under the treatment of 100μg·m L^-1.Under the treatment of Fusarium.spp,the inhibitory effect of tebuconazole was the best,and the dry weight of mycelia was less than 0.5 g under the treatment of 100μg·m L^-1.4.Pot experiment.The results showed that fludioxonil and myclobutanil had the best control effect on black spot of Atractylodes chinensis.When the concentration of fludioxonil was 60 m L/667m² and the concentration of myclobutanil was 100 m L/667m²,the control effect was more than 85%.In addition,these two fungicides had no phytotoxicity and adverse effects on the growth and development of Atractylodes chinensis.The average control effect of fludioxonil and myclobutanil was not significantly different,and the control effect was similar.Both of them could play a good role in pot experiment with high safety,and could be used in the production of Atractylodes chinensis.