Take-all is a serious disease found in wheat across the world. Haynaldia villosa is considered to be resistant to take-all at a high level. TH3 was an amphiploid （2n =42, AABBVV） between Triticum durum and Haynaldia...Take-all is a serious disease found in wheat across the world. Haynaldia villosa is considered to be resistant to take-all at a high level. TH3 was an amphiploid （2n =42, AABBVV） between Triticum durum and Haynaldia viUosa with significant resistance to take-all fungus isolated from China. In greenhouse experiment, the derivatives of the hybrid between wheat and TH3 showed better resistance to take-all than that of the wheat control. One of the derivatives named HW918-5 was selected for further analysis. Cytological and genomic in situ hybridization （GISH） analysis indicated that a monotelosome originated from H. villosa existed in the genome of the offspring of the line HW918-5. The monotelosome with promising resistant gene for take-all was located on the 3V chromosome of H. villosa in the further PCR-based molecular analysis.展开更多
Fifty six endophytic bacteria strains were isolated from the roots of wheat,and one strain named G-32 was screened with antagonism on pathogenic fungi of Gaeumannomyces graminis var.tritici.Preliminary characterizatio...Fifty six endophytic bacteria strains were isolated from the roots of wheat,and one strain named G-32 was screened with antagonism on pathogenic fungi of Gaeumannomyces graminis var.tritici.Preliminary characterization indicated that G-32 was belonged to Bacillus cereus.The inhibitory action to the fungi was assayed in lab by using the fermentable extracts of antagonistic endophytic bacteria.The results showed that mycelium of G.graminis var.tritici growed slowly and the biomass reduced 89% compared with the control 6 d after inoculation.The hyphae were deformative which broke into pieces.Colonization was studied with dual-resistant label which suggested that the endophytic bacteria strain could colonize in the root systems of wheat.The control efficacy with G-32 strain against the disease of the wheat take-all in pot tests was better than that of common used chemical fungicide Diniconazole.展开更多
Evaluation with the pot assay at seedling stage in greenhouse showed that oat (Arena saliva) was highly resistant to take-all disease to which, however, wheat (Triticum aestivum) was extremely susceptible. The oat roo...Evaluation with the pot assay at seedling stage in greenhouse showed that oat (Arena saliva) was highly resistant to take-all disease to which, however, wheat (Triticum aestivum) was extremely susceptible. The oat roots were shown to be inhibitory to the invasion and spread of take-all causing fungus G. graminis var. tritici by the following criteria: (i) less infection sites were observed (about 1/7 of those in wheat); (ii) the ectotrophic growth of G. graminis var. tritici on oat roots was much slower than that on those of wheat, and the runner hyphae appeared as kidney- or fork-shaped hyphopodia on the surface of oat roots which could not be discerned on that of wheat roots; (iii) the period from inoculation to penetration into the epidermis of oat roots was about 2.9 times as long as that of wheat; (iv) the infection hyphae were hindered substantially when it was about to penetrate into the epidermis of oat roots with the mycelium deformed; and (v) the cortical layer of oat roots was revealed to be展开更多
文摘Take-all is a serious disease found in wheat across the world. Haynaldia villosa is considered to be resistant to take-all at a high level. TH3 was an amphiploid （2n =42, AABBVV） between Triticum durum and Haynaldia viUosa with significant resistance to take-all fungus isolated from China. In greenhouse experiment, the derivatives of the hybrid between wheat and TH3 showed better resistance to take-all than that of the wheat control. One of the derivatives named HW918-5 was selected for further analysis. Cytological and genomic in situ hybridization （GISH） analysis indicated that a monotelosome originated from H. villosa existed in the genome of the offspring of the line HW918-5. The monotelosome with promising resistant gene for take-all was located on the 3V chromosome of H. villosa in the further PCR-based molecular analysis.
文摘Fifty six endophytic bacteria strains were isolated from the roots of wheat,and one strain named G-32 was screened with antagonism on pathogenic fungi of Gaeumannomyces graminis var.tritici.Preliminary characterization indicated that G-32 was belonged to Bacillus cereus.The inhibitory action to the fungi was assayed in lab by using the fermentable extracts of antagonistic endophytic bacteria.The results showed that mycelium of G.graminis var.tritici growed slowly and the biomass reduced 89% compared with the control 6 d after inoculation.The hyphae were deformative which broke into pieces.Colonization was studied with dual-resistant label which suggested that the endophytic bacteria strain could colonize in the root systems of wheat.The control efficacy with G-32 strain against the disease of the wheat take-all in pot tests was better than that of common used chemical fungicide Diniconazole.
基金This work was supported by theShaanxi Provincial Scientific Research Project (Grant No. 39725033) and the Postdoctoral Science Foundation of China (Grant No. 0208171304) and the Subject Constructional Foundation of Nanjing University (Grant No. 020
文摘Evaluation with the pot assay at seedling stage in greenhouse showed that oat (Arena saliva) was highly resistant to take-all disease to which, however, wheat (Triticum aestivum) was extremely susceptible. The oat roots were shown to be inhibitory to the invasion and spread of take-all causing fungus G. graminis var. tritici by the following criteria: (i) less infection sites were observed (about 1/7 of those in wheat); (ii) the ectotrophic growth of G. graminis var. tritici on oat roots was much slower than that on those of wheat, and the runner hyphae appeared as kidney- or fork-shaped hyphopodia on the surface of oat roots which could not be discerned on that of wheat roots; (iii) the period from inoculation to penetration into the epidermis of oat roots was about 2.9 times as long as that of wheat; (iv) the infection hyphae were hindered substantially when it was about to penetrate into the epidermis of oat roots with the mycelium deformed; and (v) the cortical layer of oat roots was revealed to be
