| Apple anthracnose caused by Colletotrichum gloeosporioides has been an important disease of postharvest apple, which caused fruit rot during storage. In this paper, after used the hypo virulence strains invade the host organization to induce the plant to produce disease-resistant, may reduce the occurrence of the plant disease. Screening hypo virulence strains through ion implantation and the magnetic field, carries on the determination to it on the apple protective function, obtained hypo virulence, and the comparison to the strain biology characteristic between the the hypo virulence strains and virulence strain, then comparison the enzymes live change after inoculate on the apple. The experimental results were summarized as follows:1. Screening hypo virulence strains and control effect1.1. Screening hypo virulence strainsScreening hypo virulence strains through ion implantation and the magnetic field ,and research the mycelium strain growth situation and sickness spotsize which occurs on the apple, obtains hypo virulence, discovered ion implantation C100-2-5 is hypo virulence and the magnetic field processes C0.25-1-2 hypo virulence to have the better protective function to the apple.1.2 The control effect of hypo virulence strain inoculated to appleThe test result indicated that, The hypo virulence strain obtains which through ion implantation the control effect is better to the apple. In controls effect by the different proportion simultaneous inoculation, the effect virulence strain and hypo virulence strain by 1: 2 proportions vaccinates is better.2. Research on biology characteristic of hypo virulence strains and virulence strainHad studied the influence of temperature, the PH value and the carbon, N sources to virulence the strain and the hypo virulence strain growth, the spore ,the spore germinstion and sporulation.2.1 Effects of temperature on mycelial growth, spore germination and sporulation of Colletotrichum gloeosporioidesThe result indicated that, the mycelium growth temperature range from10 to 35℃, the optimum temperature is 28℃, but hypo virulence strain C100-2-5 growth speed quicker under a lower temperature, the temperature of product the spore and spore germination is from 15 to 35℃, hypo virulence strain spore sprouting rate is higher at lower temperature. 2.2 Effects of pH on mycelial growth, spore germination and sporulation of Colletotrichum gloeosporioidesThe mycelium growth most suitable pH value basic is same, can grow in the pH 3～10 scope and sporulation, the most suitable pH value is 4, and spore sprouting is 4-5, but produces the spore quantity after ion implantation hypo virulence strain C100-2-5 ,actually continuously is lower than under the different pH value and the temperature after magnetic field processing C0.25-1-2 and the virulence strain.2.3 Effects of carbon sources on mycelial growth, spore germination,sporulation of Colletotrichum gloeosporioides.The result indicated that, in 7 kinds carbon sources center, the mycelium growth quickest is in apple fruit juice, growth on the mannite culture medium is slowly, but hypo virulence strains produces the spore quantity many is the maltose, virulence strains produces the spore quantity in the glucose. Take apple fruit juice as carbon sources when the mycelium growth is good, But is disadvantageous to the spore production.On the apple fruit juice culture medium spore sprouting rate is higher,the hypo virulence strain in the D- fructose and mannite sprouting rate is lower.2.4 Effects of N sources on mycelial growth, spore germination,sporulation of Colletotrichum gloeosporioidesThe virulence strain and the hypo virulence strain all in the proteinpeptone culture medium grow well, also spore sprouting rate is highest, achieves the remarkable difference with other culture medium, but theC100-2-5 strain does not have good on the protein peptone culture medium which the CO.25-1-2 strain and virulence strain grows, the virulence strain produces the sporequantity on the urea in a big way, both two hypo virulence strains are produce the spore quantity on NH4NO3 to be biggest,on the NH4SO4 is the smallest2.5 Virulence strain and hypo virulence strain lethal temperatureThe spore lethal temperature is 47℃15min or 50℃5min. But mycelium the lethal temperature is actually different, the virulence strain is60℃20min, C0.25-1-2 is 60℃25min, C100-2-5 is 60℃30min or 65℃5min.2.6 Heredity stability of Hypo virulence strainsThrough chases the generation to raise the hypo virulence strain,then separately vaccinates on the apple fruit, determination sickness spot occurs the size, the result indicated: Each generation of between sickness spot diameter had not achieved the difference is remarkable, showed the hypo virulence strain has the relative hereditystability.3. Study on the Pathogenesis of Virulence strain and hypo virulence strainThe application spectrophoto metric method the cell wall which the hypo virulence strains and the virulence strain produces to the living specimen inside and outside degrades the enzyme to carry on the active analysis,the result as follow:3.1 Change in the enzyme activity produces the cell wall degrades living specimens betweenthe hypo virulence strains and the virulence strainThe findings indicated that, between the virulence strain and the hypo virulence strain not the remarkable difference, but between various strains secretes PMG and the CX activeness all achieved the difference is remarkable. gathers the methyl galacturonic acid enzyme along with the raise number of days increaseapple anthrax secretion (PMG) activeness all has a peak value in 5thdays, after the carboxy methylcellulose enzyme (CX) activeness firstrises to fall, after 5th days achieved the peak value namely starts to drop, appears a time of peak after ninth days activeness to reduce.3.2 Change in living specimens the cell wall degrades the enzyme activityAfter the apple fruit is invaded dyes, the PMG and the Cx all activeness remarkably advances, the virulence strain and the hypo virulence strain first appear the PMG active peak, latter appears the Cx active peak. the virulence strain is vaccinating the 5th day enzyme exactly to achieve the high point, while the hypo virulence strain at 4th day. C100-2-5 and the C0.25-1-2 change tendency is similar.the virulence strain in the strain PMG active overall is lower than the hypo virulence strain, but vaccinates the virulence strain Cx active is higher than vaccinates the hypo virulence strain, also the vaccination the virulence strain and the hypo virulence strain Cx activeness all achieves the peak in 7th days.4 Research on main enzymeAfter the apple fruit inoculate the virulence strain and the hypo virulence strains, the apple fruit inβ-1,3- glucosan enzyme and several Ding nature enzyme activity all is in the trend of escalation, inoculate the virulence strain enzyme exactly is lower than the hypo virulence strain the CK in vivo enzyme activity basically to be at the steady condition, also activeness is very lowAfter studied the POD, PPO and PAL active change. The result indicated that, Three kind of enzymes activeness all achieve the high point in 4th days, but after activeness assumes the drop tendency. Vaccinates the hypo virulence strain on apple fruit, before three days and at 6th days all POD enzyme is higher than the virulence strain, but actually is lower than the virulence strain atthe 4-5th day; But vaccinates the hypo virulence strain apple fruit PPO enzyme to live continuously is lower than the virulence strain. The PAL active change is vaccinates the the hypo virulence strain enzyme to live in previous 5 days is lower than the virulence strain, after 6th days then is opposite. Different is the strain toxicity is different,causes the fruit in vivo enzyme active change also slightly to have the difference. In comparison apple also have these three kind of enzymes, but activeness is very low.Through the determination sugar content, has analyzed the soluble total sugar change. The search indicated that, in the vaccination the virulence strain strain apple fruit sugar content whole is lower than vaccinates the the hypo virulence strain content, but all higher than comparison.
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