Study The Species Of Quinoa Diseases And The Pathogen Of Its Black Stalk Disease

In recent years,as people gradually realizing the abundant nutritional value of quinoa,the planting area of quinoa has been expanded year by year.The occurrence of quinoa diseases is rapidly increasing in its main planting region,Jingle County Shanxi Province,which is known as the optimum planting region of quinoa in China.Therefore,studying the related diseases of quinoa is of great significance to protect its yield and quality.In this study,based on the investigation of the occurrence of quinoa diseases in Jingle County in 2015 and 2016,the morphological and molecular biology methods were used to isolate and identify pathogens causing quinoa black stalk disease,and the back infestation test was further carried out.Meanwhile,the biological characteristics and the 14 kinds of fungicides' laboratory inhibition test of the pathogen were studied.The results showed that there were three kinds of quinoa diseases in Shanxi province,which were downy mildew,leaf spot and black rod disease.Combining the morphological characteristics of the culture traits,conidia,pycnidia and rDNA-ITS sequence analysis,the pathogen of quinoa black stalk disease in Shanxi Province was confirmed as the genus Phoma.The symptom of the back infestation test was the same as that of the original diseased plant,and the same pathogen was isolated from the inoculated plants.For this tested strain,the optimum growth temperature is 25 ?,and the optimum pH is 7.All of the tested fungicides had inhibitory effect on quinoa black stalk disease,and the control effect of 0.5%metalaxyl + 2.5%hymexazol(AS),60%difenoconazole + 40%kresoxim-methyl(SC),10%flusilazole(EW)were the best,whereas,the control effect of kasugamycin(WP)was not satisfied.