| Eggplant(Solanum melongena L.)is a kind of vegetable widely cultivated all over the world,which plays an important role in vegetable production.Eggplant had been found a variety of diseases,if not prevented and controled in time,would lead to serious reduction.With the eggplant planting area increased year by year and a number of new varieties of planting,eggplant diseases increasingly prominent,especially in Liaoning area,eggplant planting area occupied a large proportion of greenhouse vegetable cultivation,so it is.necessary for us to strengthen the prevention and control of eggplant diseases and solving measures.In July 2016,a flower rot of eggplant was found in greenhouse in Liaoning caused by Fusarium proliferatum and the field survey found that the incidence rate of 10%-20%.The related literature at home and abroad,in recent years,by the layer of Fusarium infection of new crop disease had a rising trend,such as garlic(Allium sativum L.)stem rot(Glycine max),soybean root rot,grape fruit rot(Vitis vinifera),blueberry(Vaccinium corymbosum L.)root rot disease.Corn sheath rot,corn ear rot,a new disease layer of Fusarium infection as pathogenic bacteria occurs due to gradually become a problem could not be ignored in the production.The study of the identification of eggplant layer pathogen Fusarium rot flower at the same time,the biological characteristics of the pathogen host resistance enzyme response and chemical control of related research,aimed to lay the theoretical foundation for the diagnosis and identification of eggplant layer field control Fusarium rot of flowers.1.The damage occurrence and pathogen identification of Fusarium proliferatum causing blossom blight of eggplantA new disease was discovered and was infected with Fusarium,resulted in July 2016 in the Beizhen area of our province's Greenhouse Eggplant in greenhouse,the eggplant flower were mainly infected,the flower was infected with brown spots,hygrophanous appeared.With the development of disease,eggplant fruit was furtherly infected with pathogenic bacteria,eggplant fruit and flower could show the same symptom,with hygrophanous brown spots.In the condition of high humidity,a layer of white gray mold was found on eggplant flower and young fruit.When the onset of severe,gray mold layer would be full of flower and young fruit.A field investigation was carried out on eggplant shed with disease,and the incidence of the disease was found to be 10-20%.Based on the pathogenic bacteria colony morphology,pigment color and shape were observed,and ITS sequences of pathogenic bacteria were analyzed.The phylogenetic tree was constructed,using molecular techniques to identify the pathogen of Fusarium layer(Fusarium proliferatum).2.The pathogen biology research of Fusarium proliferatum causing blossom blight of eggplantThe pathogen was isolated from eggplant flower rot on eggplant Fusarium layer was studied the biological characteristics of the system.The mycelial growth and spore germination rate of pathogens in different media,temperature,pH,carbon source,nitrogen source land illumination were measured.The biological characteristics of the pathogen were studied by using different physiological indexes such as culture medium,temperature,pH,carbon and nitrogen sources.The results of preliminary study on eggplant layer Fusarium pathogen flower rot pathogen biological characteristics showed that the strain growth optimum culture medium was PSA,the optimum temperature was 25 ?,the optimum pH value was 7,the optimum carbon source was maltose,the best nitrogen source was ammonium sulfate.Colony lethal temperature of 55?min;conidia germination optimum temperature of 25? C,the optimum pH value was 7,the optimum carbon source was 1%dextran solution,the optimum nitrogen source was 1%ammonium chloride solution,the lethal temperature was 54? 10 min.Light have more influence on colony growth,for there is no significant difference among the spore germination.3.The host resistance response of enzymes in the process of the pathogen infectA series of resistance reactions had been occured when the plants were infected with pathogens,and the reaction mainly depended on the generation of some resistant enzymes.These enzymes including PPO,POD,CAT,PAL and SOD enzymes.In order to study the eggplant layer of Fusarium flower rot pathogenic bacteria in infection of eggplant,the above five kinds of numerical and enzyme activity in different time after inoculation of the activity,we carried out the relevant test.The test results showed that the test sample of PPO activity was8.95 U·mol-1·mg-1;POD activity was 17.27 U·mol-1·mg-1;CAT activity was 1.86 U·mol-1·mg-1;PAL activity was3.58 U·mol-1·mg-1;SOD activity was 10.97 U·mol-1·mg-1.The pathogen in inoculated leaves after infection,five kinds of enzyme activity variation trend showed increased first and then decreased.Five kinds of enzymes in different time after inoculation had reached a peak,and all have different rate of decline after reaching the peak value,were different in different time,the activity of the five enzymes,so that all kinds of enzymes in different content in plants,and in response to pathogen infections,changes of enzyme activity occurred a series of active reaction caused by the values were not the same,but also indirectly reflects all kinds of resistance to the coordinating role of different enzyme in leaf tissue.4.The field agents screening and determination of Fusarium proliferatum causing blossom blight of eggplantFusarium mycelium growth were to emerge the virulence of the determination results showed that different fungicides on fusarium mycelium growth had significant differences in inhibition rate.Fusarium of phenyl ether which were the most sensitive and the EC50 values of 0.3574 ?g/mL,was not sensitive to its mould amine most,the EC50 values of 36.5412?g/mL.13 kinds of drugs according to their chemical structure and mechanism,fusarium mycelium growth to emerge the virulence of the size of ergosterol biosynthesis inhibitors fungicides>succinate dehydrogenase inhibitor fungicides>methoxyl acrylic ester fungicide>aromatic fungicide phenyl pyrrole fungicides>benzene and imidazoles fungicide>biological pesticide>aniline pyrimidine class bactericide.Were to emerge the conidium germination of fusarium oxysporum toxicity measurement results show that different fungicide inhibition rate of germination of fusarium spores have significant differences.Fusarium conidium,emerge of pyrazole ether ester is the most sensitive and the EC50 values of 0.9987 ?g/mL,is not sensitive to its mould amine most,the EC50 values of 106.5779 ?g/mL.The eggplant flower rot were in the field of fusarium oxysporum controlresults showed that different reagents on the eggplant with flower rot fusarium oxysporum had different field control effect,among them,720 grams/liter chlorothalonil 1000 times liquid,250 grams/liter its bacteria ester 1500 times liquid,50%ether ester liquid and 25%pyrazole ether ester 3000 times liquid of control effect were more than 90%,showed good control effect.Base and aniline pyrimidine class bactericide and benzene and its mould amine imidazoles fungicide carbendazim in fusarium mycelium were growth inhibition,sporegermination inhibition and poor performance in the field control. |
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