Biodiversity Of The Genus Hypocrea/ Trichoderma In Different Grassland And Forest Ecosystems Of Inner Mongolia,Northern China

Trichoderma spp.are genus of common fungus and they widely are distributing around the world,displays a remarkable economic value in industry and agriculture.Trichoderma spp.were isolated from soil sample collected from grassland and forest ecosystem of Inner Mongolia,Northern China during 2014 to 2016.Trichoderma species identification,region distribution,biodiversity analysis,potential biocontrol and lytic enzyme evaluations were carried out.The main results were as follows: 1.Diversity of Trichoderma in Inner Mongolia.A total of 711 soil samples were collected within three consecutive years and a total of 6975 fungal colonies were isolated from which 417 were identified as Trichoderma strains,which give as 6% relative isolation rates.Trichoderma were isolated from 304 soil samples which give as an isolation rate 43.18% from the total soil samples.Trichoderma strains were identified based on molecular and morphological approaches.The identified Trichoderma strains were under 21 known species of: T.cf.harzianum(205),T.longibrachiatum(112),T.afroharzianum(27),T.koningiopsis(16),T.asperelloides(13),T.hamatum(9),T.rossicum(7),T.citrinoviride(7),T.alni(3),T.harzianum(3),T.konilangbra(2),,T.crassum(2),T.velutinum(2),T.gamsii(2),T.saturnisporum(1),T.guizhouense(1),T.sinuosum(1),T.atroviridis(1),T.koningii(1),T.virens(1)and T.polysporum(1).Of which T.cf.harzianum,T.longibrachiatum,T.afroharzianum,and T.koningiopsis were identified as the dominant species with dominance(Y)values of 0.1095,0.0476,0.00276,and 0.00058 respectively.The species amount,isolate numbers and the dominant species of Trichoderma varied between the regions.Xilingol and Hulunbuir have shown the highest diversity.The number of species distribution were varied at different altitudes and we have recorded the highest number of species isolates at an altitudes of 1000 – 1500 m.a.s.l with the highest species(15 species).T.cf.harzianum was recorded at every ecosystem with higher isolates number.Moreover,according to the phylogenetic analysis based on the three region combined(ITS+RPB+TEF-1?),isolates of CTCCSJ-G-HB41038,CTCCSJ-G-QT40324,XZ N236-3,CTCCSJ-G-HB40405,CTCCSJ-G-HB40039 and CTCCSJ-G-HB40101 indicated the new species or middle species should be existed.2.Diversity of antagonism of Trichoderma spp.In the present study,380 isolates of 21 Trichoderma species were screened for their antagonistic and antibiosis efficacy against Fusarium oxysporum(FO),Rhizoctonia solani(RS)and Botrytis cinerea(BC)in vitro.The result indicated that the antagonistic potential of 380 isolates of Trichoderma strains against FO,RS and BC were varied,which inhibited FO ranged 10.12-70.70%,BC44.18-82.98% and RS35.07-88.07% respectively.Among isolates of Trichoderma,195 isolates shew strong antagonistic potential which inhibited >50% mycelial growth of FO,319 and 377 Trichoderma isolates inhibited >50% mycelial growth of RS and BC respectively.In addition to this,we have investigated the antagonistic potential of the dominant isolated strain of T.cf.harzianum and we have found that the inhabitation to FO,BC and RS as well as the evolutionary relationship had no relevance.3.Diversity of biological control of Trichoderma spp.the efficacy of Trichoderma strains isolated to promote cucumber growth and to control Fusarium wilt disease with test seedlings were investigated.The results showed that the overall control effect of Trichoderma strains on cucumber was promising,417 strains were tested against Fusarium wilt and we have recorded a disease incidence ranged from 0-100%.From which 90 strains has shown control effect above 50%,186 strains above zero but below 50%,and 29 strains control effect were zero and 112 isolates control effects below zero.From the 90 Trichoderma isolates which were better control effect of T.cf.harzianumT1,T2,T3,T4,T5,T6,T7,T8,T10,T11 and T.atroviride(T9)exhibited the least disease incidence(by 0%)also the same strains shew 100% of Relative control effect.4.Diversity of hydrolytic enzymes of Trichoderma.Based on the in vitro testes performance we have selected 30 Trichoderma strains to study the hydrolytic enzymes.All Trichoderma isolates used in the present study produced cell wall-degrading enzymes(chitinase,?-1,3 glucanase and Cellulase).Based on the measured OD values,the enzyme activity of the Trichoderma strain was quite different.Based on our results of the in vitro experiment,at least one of the degrading enzymes has shown direct relationships to the antagonism of Trichoderma spp.The strains which has high inhibition rates has also recorded high clearance zone in chitinase activity,CTCCSJ-F-KY40053(T.afroharzianum)were also high antagonistic effects on the different pathogens tested for FO(70.70%),BS(81.09%)and RS(67.44)respectively and the same was true for ?-1,3-glucanase and cellulase activity,for instance,CTCCSJ-G-QT40113(T.longibrachiatum)and CTCCSJ-G-HB40457(T.guizhouense)with high inhibition rates of RS(71.20%),BC(78.31%)and 54.41% of FO and RS(66.17%),BC(66.54%)and 43.20% of FO respectively,which have shown the diversities on the hydrolytic enzymes.