Diagnoses, Identification And Control Of Cylindrocladium Leaf Spot Disease On Blueberry

Our research is about blueberry leaf spot disease in Dalian, Liaoning province of China.Based on disease investigation, tolerances of major planting blueberry (Vaccinium spp.)species were compared. Pathogen were separated and identification. The relationshipsbetween isolate and other Cylindrocladium were investigated by using phylogeny of derivedITS andβ-tubulin sequences. Pathogen mycelium growth inhibition were tested usingfungicide, plant resource extract and microbe resource.Based on investigation of disease index and rate to 5 major planting species, lowbushBlomidon has high disease rate which belongs to impressionable species, as well as highbushBlue crop is sustainable species with no disease. Other species shows distinct differences ofdisease index. Collecting infected leaves from blueberry nursery located the East of LiaoningProvince where has been undergone serious leaf spot disease. Separated and purificated onestrain fungi from lesions of leaf and Koch's postulates were fulfilled. With morphologicalobservation, ITS andβ-tubulin sequences' identification, we got a result as the blueberry leafspot disease' pathogen was Cylindrocladium colhounii Peerally in Liaoning Province.Fungicides like Chlorothalonil were used to pathogen conidia bourgeoning inhibiton and getwonderful effect with inhibition rate 100%. Ginkgo testa, leaves and Aloe leaves kinds ofextracts show different effect on pathogen mycelium growth. Testa extract show betterinhibition effect than all other plant resourced which MIC and MBC were determined.MIC/MBC were 293.25/345,172.5/276,86.25/86.25 mg/ml. 14 strains of microbes whichexhibit good inhibition effect were separated. Pathogen growth inhibition curves of B7, B6and C1 whom were better effect were draw also. Strain B7 was chose to L₁₆(4⁵) orthogonalexperiment. Optimization conditions are C source (glucose), N source (peptone), roomtemperature, without mineral and pH 6.4. C source and temperature are the most importantones in 5 factors chosing for experiment, at the same time, pH affects less. With 16S rDNAsequence identification, we get a result as B7 is Bacillus subtilis.