Pathogen Research And Resistance Analysis On Bulb Rot Of Lilium Oriental

Lilium Oriental often suffered various kinds of pathogens in the production andcultivation, and one of the most serious diseases was named bulb rot because of itssymptoms occurred mainly in the bulb. At present, many studies had emphasized on lilybulb rot at home and abroad. However, the existing research on Lilium Orientalpathogenesis and resistance was not detailed and deepgoing, and many key operations andsubtle technologies had not been reported. Here, we carried out the study of the pathogenand disease resistance base on Lilium oriental materials in Zhuzhou Hunan. The maincontents and results were as follows:1. The pathogen which caused Lilium Orienta bulb rot in the area of Zhuzhou Hunanwas Fusarium oxysporum, that was confirmed by morphological observation,pathogenicity test and ITS sequence analysis.2. Biological characteristics of the pathogen showed that the mycelial growth, sporeproduction and spore germination all had good performances at20~30℃, especially30℃was optimum. The conditions of neutral and alkaline were benefical to mycelial growth,whereas the acid environment was more suitable for spore production and sporegermination., which under pH6.0for the largest spore production, pH4.0for the highestspore germination rate. With different carbon source, the mycelial grow fastest when usingglycerol, spore production was the largest when using soluble starch, spore germinationrate was the highest when using mannitol. Overall, organic nitrogen source was moreconducive to mycelial growth, spore production and spore germination of the pathogenthan inorganic nitrogen source, which the mycelial grow fastest when using glycerol, sporeproduction was the largest and spore germination rate was the highest when using peptone.Light conditions had little effect on the pathogen, showed no significant difference in thetest indicators. The conidia lethal temperature was60℃for5min3. The results of fungicides toxicity through indoor determination suggested thatcarbendazim (Thompson) and chlorothalonil had good inhibition on mycelial growth, thatthe EC50of carbendazim (Thompson) was only3.17mg/L. By contrast, carbendazim(Welch) and fenaminosulf had a general inhibition on mycelial growth, and agriculturalstreptomycin with the EC50reached up to841.72mg/L showed the worst inhibition effect.4. Compared with the effect of seven inoculation methods, we found that theinoculation method of stabbing and soaking seeding was suitable for resistanceidentification of Lilium Oriental bulb rot. Furthermore, the results of resistanceidentification of30Lilium Oriental materials showed that the resistance of Lilium Orientalwas generally not high, mostly in the medium resistant and susceptible levels.5. With the analysis results of chromosomes parameters and karyotype, we inferred that the satellite on the top of chromosomes may be positive correlation with diseaseresistance, and the longer the chromosome relative length was, the worse the diseaseresistance may be.6. We found that total saponin content in Lilium Oriental materials with differentresistance levels were different in the determination test of total saponin content. Therewas also significant correlation between saponin content and resistance index(r=0.819).Additionally, the results of mixed liquid plate culture method indicated that saponinextracting solution had a certain inhibiting effect on pathogen’s mycelial growth and sporeproduction.