The internal transcribed spacer （ITS） region （ITS1, ITS2 and 5.8S rDNA） of the nuclear ribosomal DNA （nrDNA） was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the commo...The internal transcribed spacer （ITS） region （ITS1, ITS2 and 5.8S rDNA） of the nuclear ribosomal DNA （nrDNA） was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the common primers of the ITS of fungi. Around 800 bp- 1,000 bp fragments were obtained based on the DL2000 marker and the sequences of the PCR products were tested. Taking isolate USA as outgroup, the phylogenetic tree was constructed by means of maximum parsimony analysis, and the genetic evolution among isolates was analyzed. The results showed that there is a great difference between the base constitution of ITS 1 and ITS2 among various isolates. The seventeen isolates are classified into three groups, and the isolates from the same region belong to the same group, which shows the variation in geography.展开更多
In order to explore whether the endophytic Trichoderma strain P3.9 of loquat has an adverse effect on indigenous fungi in loquat rhizosphere soil, the quantitative change of aboriginal fungi is determined by dish dilu...In order to explore whether the endophytic Trichoderma strain P3.9 of loquat has an adverse effect on indigenous fungi in loquat rhizosphere soil, the quantitative change of aboriginal fungi is determined by dish dilution and plate colony-counting method with time changing in one season. The results showed that after the inoculation of endophytic Trichoderma strain P3.9, the total number of indigenous fungi in loquat rhizosphere soil had an obviously downward trend in contrast with the control which was without inoculation. For treatment groups, 5~60 d after inoculation, the number of indigenous fungi showed a cyclic upward-downward trend at a 10-d interval except for the insignificant changes from 35 to 40 d;60~90 d after inoculation, the upward-downward trend repeated at a 30-d interval. For the control group, the number of indigenous fungi first presented a downward-upward trend every 15 d during the period of 5~50 d, and then an upward-downward trend from the period of 50~70 d and the 75~85 d, and lastly continuous growth from 85 to 90 d;particularly, it did not vary greatly from 70 to 75 d. In general, the quantity of indigenous fungi is unstable in the control group which fluctuates more significantly than in the treatment group. The number of indigenous fungi in the treatment group was significantly lower than that in the control group. The Trichoderma strain P3.9 can inhibit indigenous fungi in loquat rhizosphere soil effectively.展开更多
Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola...Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola and Fusarium moniliforme were the main cucumber root rot pathogens. The isolation trials from the rhizosphere of healthy cucumber plants revealed that two fungal isolates and four bacterial isolates had antagonistic effects against cucumber root rot fungi. All the tested biocontrol agents reduced the radial growth of all the tested root rots fungi in dual cultures. However, all culture filtrates of the tested biocontrol agent significantly reduced radial growth of all the tested pathogenic fungi, except that T. harzianum. Under field conditions, soil treatment with any of T. harzianum and B. subtilis BI and BF, significantly reduced percentages of infected plants and significantly increased percentages of survived plants and fruit yield compared with the control. Application of the commercial product Harpin protein （Messenger）~ product, as a resistance inducer at 0.3, 0.5 and l g/L significantly reduced the percentage of infected plants under greenhouse and field conditions. Field experiments indicated that the average percentage of infected plants after 90 days significantly decreased. The percentage of the survived plants as well as fruit yield increased by using integrated disease management （IDM） package, including the most effective treatments： tolerant cultivar, Trichoderma harzianum granules formula as soil treatment, Purging cassia plant extract, Harpin protein, and a half dose of Vitavax/thiram comparing with the treatment recommended by the Ministry of Agricultural or applied treatments individually.展开更多
基金This work was supported by National Natural Science Fundation of China (No.30400285, 30671317), Postdoctoral Grant from Ag-riculture Sciences Academy of Heilongjiang Province (No. LRB06-010), China Postdoctoral Grant, Item for Teachers from Heilongjiang University (No. 140022), Young People’s Science Fund of Heilongjiang Province (No. QC06C012), 973(No. 2004CB117203-4), the Opening Fund of Key Opening Laboratory of Physiology and Ecology of Crop in Cold Terra of Agriculture Ministry "the Cloning and Mapping of cDNA Sequence from Related Gene Resistant to Phytophthora sojae and International Tech-nology Cooperation Item (No. 2005DFA30340).
文摘The internal transcribed spacer （ITS） region （ITS1, ITS2 and 5.8S rDNA） of the nuclear ribosomal DNA （nrDNA） was amplified via the PCR method in seventeen different isolates of Phytophthora sojae using the common primers of the ITS of fungi. Around 800 bp- 1,000 bp fragments were obtained based on the DL2000 marker and the sequences of the PCR products were tested. Taking isolate USA as outgroup, the phylogenetic tree was constructed by means of maximum parsimony analysis, and the genetic evolution among isolates was analyzed. The results showed that there is a great difference between the base constitution of ITS 1 and ITS2 among various isolates. The seventeen isolates are classified into three groups, and the isolates from the same region belong to the same group, which shows the variation in geography.
文摘In order to explore whether the endophytic Trichoderma strain P3.9 of loquat has an adverse effect on indigenous fungi in loquat rhizosphere soil, the quantitative change of aboriginal fungi is determined by dish dilution and plate colony-counting method with time changing in one season. The results showed that after the inoculation of endophytic Trichoderma strain P3.9, the total number of indigenous fungi in loquat rhizosphere soil had an obviously downward trend in contrast with the control which was without inoculation. For treatment groups, 5~60 d after inoculation, the number of indigenous fungi showed a cyclic upward-downward trend at a 10-d interval except for the insignificant changes from 35 to 40 d;60~90 d after inoculation, the upward-downward trend repeated at a 30-d interval. For the control group, the number of indigenous fungi first presented a downward-upward trend every 15 d during the period of 5~50 d, and then an upward-downward trend from the period of 50~70 d and the 75~85 d, and lastly continuous growth from 85 to 90 d;particularly, it did not vary greatly from 70 to 75 d. In general, the quantity of indigenous fungi is unstable in the control group which fluctuates more significantly than in the treatment group. The number of indigenous fungi in the treatment group was significantly lower than that in the control group. The Trichoderma strain P3.9 can inhibit indigenous fungi in loquat rhizosphere soil effectively.
文摘Over the few last years, cucumber （Cucumis sativus L） root rot disease became common and inflicted marked losses to yield in Fayoum. Isolation trails from infected cucumber roots revealed that Thielaviopsis basicola and Fusarium moniliforme were the main cucumber root rot pathogens. The isolation trials from the rhizosphere of healthy cucumber plants revealed that two fungal isolates and four bacterial isolates had antagonistic effects against cucumber root rot fungi. All the tested biocontrol agents reduced the radial growth of all the tested root rots fungi in dual cultures. However, all culture filtrates of the tested biocontrol agent significantly reduced radial growth of all the tested pathogenic fungi, except that T. harzianum. Under field conditions, soil treatment with any of T. harzianum and B. subtilis BI and BF, significantly reduced percentages of infected plants and significantly increased percentages of survived plants and fruit yield compared with the control. Application of the commercial product Harpin protein （Messenger）~ product, as a resistance inducer at 0.3, 0.5 and l g/L significantly reduced the percentage of infected plants under greenhouse and field conditions. Field experiments indicated that the average percentage of infected plants after 90 days significantly decreased. The percentage of the survived plants as well as fruit yield increased by using integrated disease management （IDM） package, including the most effective treatments： tolerant cultivar, Trichoderma harzianum granules formula as soil treatment, Purging cassia plant extract, Harpin protein, and a half dose of Vitavax/thiram comparing with the treatment recommended by the Ministry of Agricultural or applied treatments individually.
