Establishing The Inoculation System Of Phomopsis Vexans In Eggplant (Solanum Melongena L.) And Identification Of Resistance Resources

Phomopsis vexans is one of the main diseases of eggplant that has caused serious economic loss in the production of eggplant.The inoculation methods of Phomopsis vexansin eggplant was not perfect still,germplasm resources of eggplant were very scarce.In this study,germplasm resources were identified in the field preliminary.And a set of artificial inoculation method of Phomopsis vexans was established in eggplant,including the artificial inoculation methods of pathogen and its toxins of Phomopsis vexans.On the basis of this,the identification of resistant germplasm resources was carried out by the method of artificial inoculation in laboratory.In addition,the enzyme activit ies inthe resistant and susceptible materials were analyzed.The results were the following:(1)The inoculation effect on different inoculation concentrations were different,the results showed that 1×10~6spores/mL treatment was the best,which got disease quicker,eggplants began to get disease in the 9 days after inoculation,and it could distinguish the resistance level of the susceptible material in the 18 days.Therefore,the following experiments decided to adopt 1×10~6spores/mL to inoculate.Compared three methods of inoculation,including daub,acupuncture and spray,their inoculation effect were different.The results showed that after the inoculation by acupuncture,the incubation period of Phomopsis vexans was short and the disease index was high,which showed that the efficiency of the resistant identification was higher.And it could distinguish the resistance of susceptible materials in14daysafter inoculation.It found that the acupuncture method could distinguishthe different resistant materials quicklyafter using the resistant and susceptible materials.In the results of the seedling stage,it found that this three methods could distinguish the resistance of different resistant materials,and the effect of acupuncture was the best,which got disease was quickest,and it could distinguish the different materials in 12 days after inoculation.(2)Establishing the inoculation methods of toxins of Phomopsis vexans.In the artificial inoculation method of toxins,it found that toxins could inhibit the growth of eggplant.In the radicle elongation inhibition method,the greater the concentration of toxin,the greater the inhibitory effect on the elongation of the radicle and hypocotyl.The radicle length began to show significant difference under 25?g/mL treatment while the hypocotyl length began from 10?g/mL.In vitro identification method,the results showed that organs of eggplant seedling had different sensitivity to the toxins,and the hypocotyls were the most sensitive,the lateral roots were the second,a nd the main roots were the weakest.Considering all the factors,25?g/mL treatment was used as the screening concentration of toxins in vitro method.In the method of toxins soaking roots,the results showed that the symptoms of the leaves of eggplant seed lings were similar to Phomopsis vexans.3days,9days and 15days after transplanting could distinguish the resistance of the susceptible materials in the treatment of 40?g/mL,25?g/mLand 20?g/mL,respectively.Considering all the factors,the investigation method of the toxin soaking roots was that 25?g/mL soaked roots for 72h,and the disease index was investigated in the 9th day after transplanting.In the toxins soaked leaf disc method,the results showed that the symptoms of leaf discs such as water-like rot and turning yellow appeared after soaking with toxins.And different toxins concentration caused different varying degrees of lesions.The bigger the concentration of toxins,the higher disease index on the leaves,the greater the toxic effect on the leaves.And susceptible materials could be distinguished starting from10?g/mL.(3)In the field identification of 66 eggplant materials,the results showed that 15materials were resistant to Phomopsis vexans,including E038-1,E038-2,E10-1,E10-2-3,E125-1,E138-P1-1,E138-P2-1,E141-1,E185,E257,E260,E276,E330,E334,Qiuqie,in which E10-1,E330 and E334 did not get any diseases.In the laboratory artificial identification of eggplant ma terials,a resistant material,E330,and two middle resistant materials were identified after acupuncture inoculating in seedling stage.One high resistant material,E330,and two resistant materials,including E10-1 and E334,and four middle resistant materials were identified in fruit inoculation.E330 showed high resistance toPhomopsis vexansin the field,laboratory identification of seedling stage and fruit inoculation,which was the best material in this identification.(4)The results of enzyme activity showed that the activity of CAT in both ofthe resistant and susceptible materials decreased after inoculation,while the activities of SOD and SOD increase.The CAT activity of the resistant material was higher than that of the susceptible material at 0-12h after inoculation,but was less than that of susceptible material after 12h.The POD activity of the resistant material was higher than that of the susceptible material,and the peak value of POD activity reached at 24h after inoculation.The POD activity of susceptible increased in the preliminary stage,reaching the peak value at 12h.And the SOD activity of resistant and susceptible materials reached the peak value at 24h after inoculation,but the peak value of resistant material was higher than that of susceptible material.