Identification Of Foot Rot On Tomato And Screening Of Tomato Germplasm Sources Resistance To Foot Rot

Tomato foot rot caused by Ecapsici and P. parasitica is a fungal disease and happens frequentlynot only in open fields but also in protected ground. Because of the appearance and severity of footrot in the production of Chinese tomatoes cultivated in protected regions, we must find an effectivemethod to solve this problem. Disease-resistant breeding is up to now the most effective and directmethod to deal with such disease. The study began with the isolation and idenfication of thepathogen and then the biological characteristics of the pathogen, were studied; whereafter, aconvenient and simple method of screening the resistance of tomato seedlings to foot rot was found;with this method, the resistance to foot rot at seedling stage of 64 breeds which were from theTomato Breeding Institute of Horticulture College in Northeast Agricultural University wereauthenticated. The results were as follows:First, after the isolation,purification and identification of pathogen samples from differentregions in Heilongjiang province,the pathogens obtained were all P.capsici, which is one of thepathogenic fungi of tomato foot rot; Pathogentic ability of the nine isolated pathogens had somedifferences.Secondly, the culture medium suitable for the growth of the pathogen is oats culturemedium, and CA culture medium is suitable for the growth of spore; 28℃is the most appropriatetemperature both for the growth of the pathogen and the spore; the optimal pH value for the growthof pathogen is 7 and 6 for the spore; darkness can accelerate the growth of pathogen,whereas thelight can accelerate the growth of spore; sucrose is the ideal Carbon resource for the growth of thepathogen and the spore.Thirdly, the identification technology for the tomato resistance to foot rot at seedling stage wasstudied through the method of replicated orthogonal design. The result shows that the optimalcombination of identification of tomato resistance to foot rot was immersing—root inoculationmethod at 2—leaf age wih 10~7 per milliliter inoculation concentration.Finally, 64 varieties of tomato seedlings were inoculated by the above combination. The resultsof screening disease—resistant tomato materials were that there was only one medial-resistantmaterial—s.lycopersicoids Dun, others were susceptible or high susceptible materials.