The Identification, Biological Characteristics And Inhibitive Effect Of Soil-bome Pathogenic Fungi Of Three Kinds Of Trichoderma Spp.and The Growth- Promoting On Impatients Balsamina

The isolation, screening, identification, biological characteristics and inhibitive effect of soil-bome pathogenic fungi of three kinds of Trichoderma spp. were subjected to a systematic study, the growth promoting and disease control for Impatients balsamina were also carried out. Optimal conditions of Trichoderma spp. in growth and sporulation were determined, which providing a basis for the production and application of Trichoderma immune-inducer-like bio-fertilizer. Biocontrol Trichoderma strains with the growth promoting effect of garden plants Impatients balsamina were obtained to lay the foundation for the Trichoderma spp. applications in the field of agriculture and forestry and environmental protection.1.73 Trichoderma strains were isolated from 64 soil samples which collected from the eight species of garden plant rhizosphere soil of seven plots in Harbin and Qiqihar City of Heilongjiang Province. Three Trichoderma strains were screened with rapid mycelial growth and sporulation and they could produce a large amount conidia within a short time by plate culture and microscopic observation of its morphological characteristics. The results of morphological and molecular biological identification analysis showed that the three kinds of Trichoderma were T. harzianum, T. brevicompactum and T. longibrachiatum, which named as Th-81, Tb-50 and T1-70, respectively.2. The dual culture between each kind of Trichoderma and soil-bome pathogenic fungi and each kind of soil-bome pathogenic fungi cultured on the PDA with Trichoderma fermentation broth were carried out. The results displayed that the three kinds of Trichoderma had different degrees of antagonism on the five kinds of pathogens. The inhibitive effect of Th-81 was the best and its inhibition rates was significantly higher than that of Tb-50 and Tl-70 in the dual culture. On the other hand, the inhibitive effect on pathogens of Tb-50 and Tl-70 were better than that of Th-81 in the test of the culture on the PDA with Trichoderma fermentation broth.3. Impatients balsamina was a plant with both ornamental and medicinal value, and its seeds and stems were called as Jixingzi and Fengxiantougucao in Chinese traditional medicine, respectively. At present, Jixinzi had a large market demand. Using conidia solution of Trichoderma poured on the roots of Impatients balsamina, the results showed that all strains of Trichoderma could promote the growth of Impatients balsamina. The T. brevicompactum, Tb-50 had the best effect, which can extend as much as possible the flowering, increase the amount of flowering, the yield of stems and seeds of Impatients balsamina. Not only increasing the ornamental value of Impatients balsamina, but also Jixingzi yield, which play a positive role for income. Moreover, the results in the study also showed that the three konds of Trichoderma including Th-81, Tb-50 and T1-70 have some degrees inhibition on powdery mildew of Impatients balsamina, and the inhibitive effect of Tb-50 was the best.4. The result of biological characteristics analysis on Tb-50 showed that PDA medium was the best one suited mycelical growth and sporulation of Tb-50; the optimal light condition for Tb-50 was alternation of light and dark (brightness ratio of 1:1); the optimal temperature for Tb-50 was 25-30 ℃; the optimal PH for Tb-50 was 6-7.