Collection,Identification And Multifunctional Evaluation Of Trichoderma Resources In Farmland Of Huang Huai Hai Region

In this paper,we studied the diversity of Trichoderma from the farmland soils in the Huang-Huai-Hai area,and carried out research on promoting growth,antagonism,enzyme activity and colonization ecology.The results are as follows:(1)276 soil samples were collected from Hebei,Henan,Shandong,Tianjin and Beijingin in two seasons.418 Trichoderma strains were isolated from soils by using soil dilution plating method.With the combination of morphological analysis and molecule method,12 species were identified as followed: T.harzianum(249 isolates),T.atroviride(61),T.longibrachiatum(37),T.brevicompactum(31),T.asperellum(12),T.koningiopsis(9),T.aureoviride(5),T.ctrinoviride(4),T.virens(4),T.pleuroticola(3),T.konigii(2),T.aggressivum(1).(2)Through the diversity analysis,it was found that the first dominant species were T.harzianum,and the second dominant species began to distinguish,such as T.atroviride was the dominant species in Hebei province,T.brevicompactum was the dominant species in Henan Province,T.atroviride was the dominant species of Shandong Province.Besides,The dominant species of wheat and maize were T.longibrachiatum and T.atroviride.The spring dominant species was T.longibrachiatum and T.atroviride was the dominant species in summer.(3)The results of niche analysis showed that T.harzianum had the largest niche breadth,belonged to the dominant population in the area.In addition,There is a high niche overlap between different Trichoderma species such as T.longibrachiatum and T.harzianum,T.harzianum and T.atroviride,T.atroviride and T.Longibrachiatum.(4)418 strains of Trichoderma were tested for growth promotion and antagonistic activity.76 strains of Trichoderma were screened out for promotion.164 strains of Trichoderma were resistant to 50% of the 5 pathogens,which reached 60%of a total of 34 strains.The rate of inhibition of Fusarium oxysporum.sp.cucumebrium Owen was 70.86%,Fusarium oxysporum.sp.fragariae was 69.35%,Pythium aphanidermatum was 81.66%,Lettuce sclerotiorum was 87.84% and Rhizotonia cerealis was 82.69%.(5)Combined with the above experiment,15 strains of Trichoderma were selected for pot experiment.The results showed that the promotion effect ofTrichoderma had a difference.Specifically,237-1P2 strain had obvious effect on the whole plant.158-2M1 and 223-2M1 had obvious effect on the aerial part of the plant,among which 223-2M1 promoted the elongation of fine roots,176-1M1 had obvious effect on the elongation of underground roots,and 210-2P1 strain promoted the elongation of coarse roots.(6)The quantitative determination of cellulase,chitinase,?-1,3-glucanase and protease were carried out on the selected 15 strains of Trichoderma.The results showed that the largest strain of chitinase was 176-1M1,the largest strain of dextranase was 219-1P1,the largest strain of protease was 199-2P3,and the cellulase activity was 223-2M1.According to the Pearson correlation test,there was a certain correlation between chitinase activity was associated with Rhizotonia cerealis(r=0.669)and Pythium aphanidermatum(r=0.553),cellulase activity and Rhizotonia cerealis(r=0.839)and Pythium aphanidermatum(r=0.651),protease activity and Fusarium oxysporum.sp.cucumebrium Owen(r=0.694)and Pythium aphanidermatum(r=0.639)at p <0.05.In addition,there was no correlation between dextranase activity and the inhibitory rate.(7)Based on the screening results,a highly effective functional strain T.harzianum 237-1P2 was selected to study its ecological distribution in soil.The results showed that Trichoderma was inoculated in soil at 5-10 cm to maximize the colonization effect and could spread to 15-20 cm and 25-30 cm on the 7th day,and could form effective colonization.Then the amount of Trichoderma was the highest at the 14 th day,and the 2-4cm and 6-8cm of the plants were 2.15 and 2.59 times higher than the initial values,respectively.The 2-4cm and 6-8cm of the plants were 3.04 and2.74 times higher than the initial values.The amount of microbial bacteria in the soil increased with the increase of Trichoderma,the changes of fungi and Trichoderma changes in the opposite trend,the changes of actinomycetes are basically 15-20 cm and 25-30 cm soil layer higher than the upper layer.