Key Laboratory of Grassland Ecosystems

Lanzhou, China

Key Laboratory of Grassland Ecosystems

Lanzhou, China
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Zhang S.,Gansu Agricultural University | Zhang S.,Key Laboratory of Grassland Ecosystems | Zhang S.,Pratacultural Engineering Laboratory of Gansu Province | Zhang S.,Sino Us Centers For Grazingland Ecosystems Sustainability | And 6 more authors.
BioControl | Year: 2014

Trichoderma longibrachiatum can be used for the control of Heterodera avenae in crops, but the effectiveness and possible mechanisms are unknown. Here we determined the efficacy and the mechanism responsible for the nematode control in spring wheat (Triticum aestivum L.). Wheat seedlings inoculated with T. longibrachiatum at the concentrations from 1.5 × 104 to 1.5 × 108 spores ml-1 significantly increased plant height, root length, and plant biomass; decreased H. avenae infection in both rhizospheric soil and roots; and enhanced chlorophyll content, root activity, and the specific activities of resistance-related enzymes (peroxidase, polyphenol oxidase and phenylalanine ammonia lyase), compared to the control. Those reactions occurred soon after T. longibrachiatum inoculation and the effect reached the maximum 7-9 days after inoculation. Promoting competitive plant growth and inducing enzyme-trigged resistance serve as the main mechanism responsible for T. longibrachiatum against H. avenae. T. longibrachiatum can be considered an effective biocontrol agent against H. avenae in wheat. © 2014 International Organization for Biological Control (IOBC).


Zhang S.,Gansu Agricultural University | Zhang S.,Key Laboratory of Grassland Ecosystems | Zhang S.,Pratacultural Engineering Laboratory of Gansu Province | Zhang S.,Sino Us Centers For Grazingland Ecosystems Sustainability | And 10 more authors.
Biological Control | Year: 2014

Heterodera avenae is a devastating plant pathogen that causes significant yield losses in many crops, but there is a lack of scientific information whether this pathogen can be controlled effectively using biocontrol agents. Here we determined the parasitic and lethal effects of Trichoderma longibrachiatum against H. avenae and the possible mechanism involved in this action. Both in vitro and greenhouse experiments were conducted. In vitro, T. longibrachiatum at the concentrations of 1.5×104 to 1.5×108spores per ml had a strong parasitic and lethal effect on the cysts of H. avenae, with the concentration of 1.5×108spores per ml having >90% parasitism 18days after treatments. In greenhouse, T. longibrachiatum inoculation decreased H. avenae infection in wheat (Triticum aestivum) significantly. Observations with microscopes revealed that after mutual recognition with cysts, the spore of T. longibrachiatum germinated with a large number of hyphae, and reproduced rapidly on the surface of cysts. Meanwhile, the cysts surface became uneven, with some cysts producing vacuoles, and the others splitting. Finally the cysts were dissolved by the metabolite of T. longibrachiatum. Chitinase activity increased in the culture filtrates of T. longibrachiatum and reached the maximum 4days after inoculation in the medium supplemented with colloidal chitin (1.02U/minperml) and nematode cysts (0.78U/minperml). The parasitism and inhibition of cysts through the increased extracellular chitinase activity serves as the main mechanism with which T. longibrachiatum against H. avenae. In conclusion, T. longibrachiatum has a great potential to be used as a biocontrol agent against H. avenae. © 2014 Elsevier Inc.


Zhang S.,Gansu Agricultural University | Zhang S.,Key Laboratory of Grassland Ecosystems | Zhang S.,Sino Us Centers For Grazingland Ecosystems Sustainability | Gan Y.,Gansu Agricultural University | And 3 more authors.
Frontiers in Plant Science | Year: 2016

Soil salinity is a serious problem worldwide that reduces agricultural productivity. Trichoderma longibrachiatum T6 (T6) has been shown to promote wheat growth and induce plant resistance to parasitic nematodes, but whether the plant-growth-promoting fungi T6 can enhance plant tolerance to salt stress is unknown. Here, we determined the effect of plant-growth-promoting fungi T6 on wheat seedlings’ growth and development under salt stress, and investigated the role of T6 in inducing the resistance to NaCl stress at physiological, biochemical, and molecular levels. Wheat seedlings were inoculated with the strain of T6 and then compared with non-inoculated controls. Shoot height, root length, and shoot and root weights were measured on 15 days old wheat seedlings grown either under 150 mM NaCl or in a controlled setting without any NaCl. A number of colonies were re-isolated from the roots of wheat seedlings under salt stress. The relative water content in the leaves and roots, chlorophyll content, and root activity were significantly increased, and the accumulation of proline content in leaves was markedly accelerated with the plant growth parameters, but the content of leaf malondialdehyde under saline condition was significantly decreased. The antioxidant enzymes-superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in wheat seedlings were increased by 29, 39, and 19%, respectively, with the application of the strain of T6 under salt stress; the relative expression of SOD, POD, and CAT genes in these wheat seedlings were significantly up-regulated. Our results indicated that the strain of T6 ameliorated the adverse effects significantly, protecting the seedlings from salt stress during their growth period. The possible mechanisms by which T6 suppresses the negative effect of NaCl stress on wheat seedling growth may be due to the improvement of the antioxidative defense system and gene expression in the stressed wheat plants. © 2016 Zhang, Gan and Xu.


Zhang S.,Gansu Agricultural University | Zhang S.,Key Laboratory of Grassland Ecosystems | Zhang S.,Pratacultural Engineering Laboratory of Gansu Province | Zhang S.,Sino Us Centers For Grazingland Ecosystems Sustainability | And 5 more authors.
Applied Soil Ecology | Year: 2015

Meloidogyne incognita is one of the most important soil-borne and plant parasitic pathogens in cucumber worldwide. An ideal strategy is to develop and use effective and environmentally-friendly bio-control agents to control the plant parasitic pathogen M. incognita. This study determined the biocontrol efficacy of Trichoderma longibrachiatum, a fungal species native to China, against M. incognita. In vitro, T. longibrachiatum at the concentrations of 1.5×105 to 1.5×107 conidiaml-1 had a strong lethal and parasitic effect on the second stage juveniles of M. incognita, with the concentration of 1.5×107 conidiaml-1 inhibited and parasitized the second stage juveniles >88% 14 days after treatments. Microscope observations revealed that after the mutual recognition with the second stage juveniles, the conidia of T. longibrachiatum adhered or parasitized on the surface of second stage juveniles, germinated with a large number of hyphae and penetrated the integument, and was reproduced on the surface of second stage juveniles. Meanwhile, the surface of second stage juveniles became deformed and some were completely dissolved by the metabolite of T. longibrachiatum. The maximum protease activity of T. longibrachiatum was 3.35Umin-1ml-1 at the 5th day after the treatment of second stage juveniles. In greenhouse experiments, the concentrations of T. longibrachiatum ranging from 1.5×105 to 1.5×107 conidiaml-1 all decreased M. incognita infection and increased plant height, root length, shoot and root fresh weights in cucumber significantly compared to the control. T. longibrachiatum can be considered to be a promising bio-control agent against M. incognita with a high efficacy. © 2015.

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