| Trichoderma is a kind of important biocontrol fungus,widely distributed in soil,marine and plant body on various substrates.Many species of Trichoderma distributing in the soil have good inhibitory effect on soil borne diseases.In this study,we isolated Trichoderma strains from the soil,using Rhizoctonia cerealis and 3 strains of wheat root rot fungi as target fungus to screen and investigate its growth promoting effect on wheat of Trichoderma strain,the main results are as follows: 1.Antagonistic effect screening of Trichoderma strainsDuring 2012-2013,70 Trichoderma strains were obtained by the method of separate dilution plate from the soil that was collected from Jinnan,Dezhou,Liaocheng,Heze,Tai'an,Zibo,Binzhou,Weifang,etc in Shandong Province.Using Rhizoctonia cerealis WK-207 as target fungi for the first screening,4 strains were screened from 80 Trichoderma strains including 10 strains of Trichoderma saved previously in our laboratory.Rhizoctonia cerealis WK-207,Fusarium culmorum WF-25,Fusarium proliferatum JM-4 and Fusarium oxysporum WF-51 was used for the second screening.Meanwhile,seven species were tested character,including growth rate,inhibition rate,temperature resistance,acid and alkali resistance,sporulation,volatility and so on.The best of Trichoderma strains were comprehensively evaluated by The Grey Relational Degree Analysis,which results is that H18-1-1 strain's score was 0.7751,followed with TF28 that was 0.7727.H18-1-1 and TF28 were screened out to be the better Trichoderma strains.2.Identification of H18-1-1 and TF28Using of morphological taxonomy and 5.8SrDNA-ITS sequence analysis,TF28 and H18-1-1 were similar with Trichoderma HQ229943 similarity of 100%.H18-1-1 and TF28 were identified to be Trichoderma atroviride.3.Biocontrol effective and enzyme activity of wheat defense enzymes when using TF28 andH18-1-1 strains in greenhouseThe biocontrol efficacy of Trichoderma was tested in greenhouse after inoculating Rhizoctonia for 21 days.The results show that the biocontrol efficacy is 63.63% and 54.45%when Inoculating H18-1-1 and TF28 respectively.it turned out that compared to control,the activities of SOD,POD and CAT related to anti-disease-substance synthesis is higher in the leaves of wheat treated by H18-1-1 and TF28.4.The growth-promoting effection to wheat seedling of Trichoderma in sand cultureWheat root was dipped by spore suspension of TF28 and H18-1-1 after the wheat growth in hydroponic for 3 days,then turn the wheat in to sand culture for 35 days.The results show that the root vigor was 378.76 ug /(g.h)after inoculation of H18-1-1 and TF28,which was visibly higher than control.5.Diseases prevention and growth-promoting effects of different Trichoderma strains inoculating to wheatTF28,H18-1-1,T10 strain was used to the field of wheat for the testing of growth-promoting and disease controlling.Some index were detected to estimate the growth-promoting effection of H18-1-1 to the wheat,including plant height,root length,root number,fresh weight,dry weight and other indicators at early tillering stages and early jointing stages.The results showed that the growth of wheat was promoted significantly by inoculating H18-1-1.The biocontrol effect of the treatment inoculated by H18-1-1was 27.66%,followed by the treatment of T10 and TF28 which was 25.53% and 17.02% respectively.The disease index of wheat sharp display in the late grain filling,H18-1-1 treatment control effect reached 65.86%.We can conclude through comprehensive analysis of the experimental results in the field that H18-1-1 is the best strain for growth promotion and diseases control. |
PDF Full Text Request