Identification And Pharmaceutical Screening Of Sooty Blotch Pathogen On Gardenia Jasminoides Eills

Gardenia jasminoides Ellis is a kind of dried and ripe fruit of Ruacbieae.Gardenia having a long history of use,which is recorded in all dynasties of herbs and pharmacopoeia.Gardenia has the effect of clearing away heat,anti-inflammatory,anti-oxidation,anti-tumor,lowering blood lipid,enhancing immunity and so on.It is often used in clinical clearing away trouble,diuretic drenching,anti-inflammatory,detumescence,clearing heat,promoting gallbladder,external treatment for torsion and contusion pain.Due to its rich pharmacological activity and effective application value,it is now widely welcomed in the market and becomes a research hotpot.With the increasing demand of market,clinical and scientific researchers for gardenia,wild gardenia fruit resources have been seriously deficient.China has established a large area of Chinese herbal medicine gardenia planting base in many provinces and cities,but the large-scale artificial concentrated planting of gardenia has aggravated the occurrence of diseases and insect pests.As one of the main fungal diseases of gardenia,sooty blotch is prone to produce disease spots on leaves and twigs.Its cause is unknown and its incidence range is wide.Through morphology observation,microscopic identification,the study is made of normal tissue separation after determination of pathogenic and Koch's rule validation,technical analysis,using the modern molecular biology of gardenia sooty blotch symptoms and pathogen of systematic identification,for understanding the biological characteristics of pathogen,and indoor screening,bacteriostatic agent for gardenia sooty blotch prevention and control to provide scientific theoretical basis and effective method.The results are as follows:After 24-36 h on PDA medium,the strain began to grow sparse white hyphae,and the colonies presented nearly round or oval shape.After 3 d,the bacteria gradually changed from the center to the surrounding dark green.After culture for about 21 d,air generated hyphae was generated at the edge of the colony,and oily translucent liquid began to be generated in the center of the colony,and 1-2 ring marks with irregular boundaries were generated on the surface of the colony.Under microscopic identification,the mycelium wall was thin and transparent,with small curvature,few branches,slender and fascicular,with obvious separation.Conidia oblong,a few gourd-shaped,more transparent,ascus long,a few lanceolate,slightly curved,containing several spores.Strains of DNA as template,the specificity of the strain amplification received 539 bp fragments,with known in NCBI gene sequence similarity comparison,the results showed that the homology of the highest strain is Glomerella septospora?every other bacteria spore plexus shell?,similarity was 99%,ultimately determine the pathogen of ascomycetes small clump shell small clump shell genera spore bundle insulation shell bacteria?Glomerella septospora?.The results of host range experiment showed that only a few plants showed infection after 3 d inoculation,namely Michelia crassipes Law,Maesa japonica?Thunb.?Moritzi.,Platycodon grandiflorus?Jacq.?A.DC.and Cynanchum atratum Bunge.Michelia crassipes Law,the most serious one,has an incidence of up to 80%,followed by Maesa japonica?Thunb.?Moritzi.,Platycodon grandiflorus?Jacq.?A.DC.and Cynanchum atratum Bunge.with an incidence of 70%,60%and 60%respectively.Other plants have no incidence,considering that coal smudge may have a certain specificity.Biological characteristics experimental study showed that coal sludge gardenia disease pathogen hypha growth optimal condition is 25?,pH of 7,the best carbon and nitrogen source respectively,sucrose and potassium nitrate,illumination had no significant effect on mycelial growth;Fruiting body germination optimum conditions for 30?,pH of 7,the best carbon and nitrogen source respectively,sugar and yeast extract,light subsidiary entities had no effect on germination;Fruiting body and mycelium of the lethal temperature 65?.The relationship between pH and germination of fruiting bodies was similar to that of mycelial growth.The indoor toxicity test results of antibacterial agents showed that pentazolol had the best bactericidal effect on sooty blotch pathogen,and the linear regression equation was Y=0.4953X+6.1091(r=0.991,EC₅₀=0.11).The regression equations were Y=0.3336X+4.9171(r=0.991,EC₅₀=1.28),Y=0.3827X+4.2926(r=0.970,EC₅₀=6.63),and Y=0.5762X+3.6644(r=0.827,EC₅₀=10.16).The experimental results showed that 70%methyl thionol-43%pentazolol,70%methyl thionol-80%mancozeb,80%mancozeb,80%mancozeb,80%mancozeb,43%pentazolol and 43%pentazol-60%mancozeb all showed good synergistic effects at different volume.Among them,the mixture of 70%methyl thionol-43%pentazolol and 43%pentazol-60%phenyl ether metronidazole had significant antibacterial effect,and the toxicity ratio of each group was greater than 1.1.The results showed that most of the tested herbs had some inhibitory effect on sooty blotch pathogen.Among them,the alcohol extracts of phellodendron chinensis,Clematis chinensis,Coptis chinensis,rhizoma atractylodis,radix sophorae flavescentis,rhizoma anemarrhenae,dandelion had better bacteriostatic effect on the bacteria isolated from the spore cluster,and the bacteriostatic rate was higher than that of the control group.Among them,the extract of 40 mg/ml of cortex phellodendron chinensis had the best effect in inhibiting the growth of mycelia.After 7 days,the diameter of the bacterial colony of the isolated spore cluster was only 16.45±5.59 mm,and the bacteriostasis rate was as high as 83.47%,which was 30.84%higher than that of the control group using the chemical agent bactericide.Smilax glabra rhizome and seed of Asiatic plantain promoted the growth of mycelia instead,and the inhibition rate was negative,so it was not recommended for the development of biological control.