Fusarium wilt, caused by Fusarium oxyporum f. sp. cubense(Foc), is the most serious disease affecting banana production.To clarify the distribution of the Foc races in Fujian Province of China, 79 soil samples were co...Fusarium wilt, caused by Fusarium oxyporum f. sp. cubense(Foc), is the most serious disease affecting banana production.To clarify the distribution of the Foc races in Fujian Province of China, 79 soil samples were collected from four regions of Zhangzhou City, the primary banana production area in Fujian. We isolated and identified 12 Foc strains based on internal transcribed spacer(ITS) sequence analysis, PCR amplification by using Foc-specific primers and pathogenicity assays.Our analysis indicated that 11 isolates belong to Foc race 1, and 1 isolate belongs to the Foc tropical species race 4(TR4).Although TR4 has previously been reported to occur in primary banana-producing provinces, such as Hainan, Guangxi,and Guangdong of China, this is the first report of TR4 isolated from the soil in Fujian Province. Monitoring the presence of Foc, in particular, the TR4 strains in the soil, is the basic strategy to prevent and control Fusarium wilt.展开更多
Endophytic bacteria colonizing the shoot-tips of banana cv. Grand Naine were isolated and tested for the antagonistic activity against the Panama wilt pathogen Fusarium oxysporum f. sp. cubense (Foc). Pre-isolation, t...Endophytic bacteria colonizing the shoot-tips of banana cv. Grand Naine were isolated and tested for the antagonistic activity against the Panama wilt pathogen Fusarium oxysporum f. sp. cubense (Foc). Pre-isolation, the suckers were given extensive disinfection treatments and the homogenate from the excised shoot-tip portion was plated on nutrient agar (NA) and trypticase soy agar (TSA). This yielded altogether 47 isolates: 26 on NA and 21 on TSA, respectively, from the 10 suckers collected during August to February. The number of bacterial isolates obtained per sucker varied from one to 15 based on colony characteristics registering up to 10 distinct species per shoot-tip based on 16S rRNA sequence analysis. The 47 isolates belonged to 19 genera and 25 species under the phylogenetic classes of Actinobacteria, α- and γ-Proteobacteria and Firmicutes. Actinobacteria constituted the predominant phylum (55% isolates) with the constituent genera of Arthrobacter, Brevibacterium, Corynebacterium, Curtobacterium, Kocuria, Kytococcus, Micrococcus, Naumanella, Rothia and Tessaracoccus spp. and an unidentified isolate belonging to the family Frankiaceae. Proteobacteria constituted the second major phylum (Brevundimonas, Enterobacter, Klebsiella, Pseudomonas, Serratia and Sphingomonas spp.) followed by Firmicutes (Bacillus and Staphylococcus spp.). Antagonistic activity of the endophytes against Foc was tested through agar plate assays (pit and spot applications on fungal lawn) employing potato dextrose agar and NA. Endophytic Pseudomonas aeruginosa (isolate GNS.13.2a) which was associated with a single sucker showed significant growth inhibition effect on Foc while Klebsiella variicola (GNS.13.3a) and Enterobacter cloacae (GNS13.4a) exhibited moderate inhibition. The study brings out considerable sucker to sucker variation in the associated cultivable endophytic bacteria in “Grand Naine” banana and identifies a few bacterial endophytes with biocontrol potential against the devastating Foc pathogen.展开更多
Fusarium wilt of banana, which is caused by Fusarium oxysporum f. sp. cubense tropical race 4 （Foc TR4）, is a serious soil-borne fungal disease. Now, the epigenetic molecular pathogenic basis is elusive. In this stu...Fusarium wilt of banana, which is caused by Fusarium oxysporum f. sp. cubense tropical race 4 （Foc TR4）, is a serious soil-borne fungal disease. Now, the epigenetic molecular pathogenic basis is elusive. In this study, with methylation-sensitive amplification polymorphism （MSAP） technique, DNA methylation was compared between the leaves inoculated with Foc TR4 and the mock-inoculated leaves at different pathogenic stages. With 25 pairs of primers, 1 144 and 1 255 fragments were amplified from the infected and mock-inoculated leaves, respectively. DNA methylation was both changed and the average methylated CCGG sequences were 34.81 and 29.26% for the infected and the mock-inoculated leaves. And DNA hypermethylation and hypomethylation were induced by pathogen infection during all pathogenic stages. Further, 69 polymorphic fragments were sequenced and 29 of them showed sequence similarity to genes with known functions. And RT-PCR results of four genes indicated that their expression patterns were consistent with their methylation patterns. Our results suggest that DNA methylation plays important roles in pathogenic response to Foc TR4 for banana.展开更多
Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense tropic race 4(Foc TR4), is a typical vascular and soil-borne disease which has significantly threatened the sustainable development of banana indust...Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense tropic race 4(Foc TR4), is a typical vascular and soil-borne disease which has significantly threatened the sustainable development of banana industry. In order to reveal the infection process and pathogenesis of Foc TR4, the young mycelia(66.7 mg/ml) of wild-type strain of Foc TR4(WT-Foc TR4) cultured for 18-20 h were lysed with enzyme mixture for protoplast formation, which consisted of 25 mg/ml driselase, 0.4 mg/ml chitinase, 15 mg/ml lysing enzyme and 1.2 mol/L potassium chloride. The resulted protoplasts of 2×10~7 cells/ml were used to test the efficiency of transformation mediated by polyethylene glycol, and up to 9 transformants per microgram of DNA were obtained. AmCyan, RFP and YFP genes were stably transferred into the WT-Foc TR4, separately, using the protoplast transformation system. The gene FoOCH1 encoding α-1, 6-mannosyltransferase in the WT-Foc TR4 was knocked out using the split-marker recombination technology. The genetic transformation and gene knockout system in this pathogen lays a foundation for the study of functional genomics and plant-pathogen interactions.展开更多
[Objective]The paper was to understand the field resistance performance of different banana varieties and the prevention and control ef-fect of different fertilizers,so as to provide technical reference for the preven...[Objective]The paper was to understand the field resistance performance of different banana varieties and the prevention and control ef-fect of different fertilizers,so as to provide technical reference for the prevention and control of Fusarium wilt.[Method]Field trials were set up with three treatments:shrimp peptide organic fertilizer+shrimp peptide special protection+shrimp peptide fruit Yekang(simplified as shrimp peptide organic fertilizer treatment),conventional organic fertilizer+microbial preparations(simplified as microbial treatment),and conventional or-ganic fertilizer(simplified as control).Four different banana varieties of Brazilian banana,Guijiao No.1,Nantianhuang,and Yunjiao No.1 were se-lected for the field trial.The disease incidence of Fusarium wilt and the control effects of three fertilizers were investigated during four time periods.[Result]The disease incidence of four varieties in three treatments varied.The disease incidence of Nantianhuang and Yunjiao No.1 were signifi-cantly lower than that of other two varieties.There was also significant difference in disease incidence of three treatments.The disease incidence from high to low was control>shrimp peptide organic fertilizer treatment>microbial treatment.The average monthly TR4 pathogen content in heavily infected banana plantation was more than 2000 copies,while the highest one reached 15148.9 copies.[Conclusion]Microbial agents reduced the disease incidence of Fusarium wilt to some content.Nantianhuang and Yunjiao No.1 showed the highest disease resistance compared with other varieties.However,their resistance needs to be further improved before practical application.展开更多
A biocontrol strain HJX1,which had good inhibitory effect against Fusarium oxysporum f. sp. cubense,was identified as Bacillus subtilis based on traditional morphology,16 S rRNA gene sequence and fatty acid profiles. ...A biocontrol strain HJX1,which had good inhibitory effect against Fusarium oxysporum f. sp. cubense,was identified as Bacillus subtilis based on traditional morphology,16 S rRNA gene sequence and fatty acid profiles. The sequence of 16 S rRNA gene had 99% homology to B. subtilis according to the DNA fragment of 1 521 bp amplified with a pair of universal primers,P0 and P6,of bacteria. Confront culture with pathogenic fungi showed that this strain had good inhibitory effect against 10 pathogenic fungi.展开更多
Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude prote...Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude protein from fermentation broth of the strain HJX1 through ammonium sulfate precipitation, and prelimina- rily studied fungistatic activities at different conditions. The results showed that the crude protein was insensitive to protease K, trypsin or ultraviolet radiation. The fungistatic activity was unchanged when treated in water batch at 40 ℃, 60 ℃, 80 ℃ or 100 ℃ for 30 min, and the fungistatic activity maintained 60% when trea- ted at 121℃ for 30 min.展开更多
基金supported by the National Natural Science Foundation of China (31601583)the Natural Science Foundation of Fujian Province, China (2016J01113)+1 种基金the Young Teacher Education Research Project of Fujian Province, China (JAT160178)the Fujian Agriculture and Forestry University Outstanding Youth Scientific Research Project, China (xjq201625)
文摘Fusarium wilt, caused by Fusarium oxyporum f. sp. cubense(Foc), is the most serious disease affecting banana production.To clarify the distribution of the Foc races in Fujian Province of China, 79 soil samples were collected from four regions of Zhangzhou City, the primary banana production area in Fujian. We isolated and identified 12 Foc strains based on internal transcribed spacer(ITS) sequence analysis, PCR amplification by using Foc-specific primers and pathogenicity assays.Our analysis indicated that 11 isolates belong to Foc race 1, and 1 isolate belongs to the Foc tropical species race 4(TR4).Although TR4 has previously been reported to occur in primary banana-producing provinces, such as Hainan, Guangxi,and Guangdong of China, this is the first report of TR4 isolated from the soil in Fujian Province. Monitoring the presence of Foc, in particular, the TR4 strains in the soil, is the basic strategy to prevent and control Fusarium wilt.
文摘Endophytic bacteria colonizing the shoot-tips of banana cv. Grand Naine were isolated and tested for the antagonistic activity against the Panama wilt pathogen Fusarium oxysporum f. sp. cubense (Foc). Pre-isolation, the suckers were given extensive disinfection treatments and the homogenate from the excised shoot-tip portion was plated on nutrient agar (NA) and trypticase soy agar (TSA). This yielded altogether 47 isolates: 26 on NA and 21 on TSA, respectively, from the 10 suckers collected during August to February. The number of bacterial isolates obtained per sucker varied from one to 15 based on colony characteristics registering up to 10 distinct species per shoot-tip based on 16S rRNA sequence analysis. The 47 isolates belonged to 19 genera and 25 species under the phylogenetic classes of Actinobacteria, α- and γ-Proteobacteria and Firmicutes. Actinobacteria constituted the predominant phylum (55% isolates) with the constituent genera of Arthrobacter, Brevibacterium, Corynebacterium, Curtobacterium, Kocuria, Kytococcus, Micrococcus, Naumanella, Rothia and Tessaracoccus spp. and an unidentified isolate belonging to the family Frankiaceae. Proteobacteria constituted the second major phylum (Brevundimonas, Enterobacter, Klebsiella, Pseudomonas, Serratia and Sphingomonas spp.) followed by Firmicutes (Bacillus and Staphylococcus spp.). Antagonistic activity of the endophytes against Foc was tested through agar plate assays (pit and spot applications on fungal lawn) employing potato dextrose agar and NA. Endophytic Pseudomonas aeruginosa (isolate GNS.13.2a) which was associated with a single sucker showed significant growth inhibition effect on Foc while Klebsiella variicola (GNS.13.3a) and Enterobacter cloacae (GNS13.4a) exhibited moderate inhibition. The study brings out considerable sucker to sucker variation in the associated cultivable endophytic bacteria in “Grand Naine” banana and identifies a few bacterial endophytes with biocontrol potential against the devastating Foc pathogen.
基金supported by the National Natural Science Foundation of China (30860149 and 31360364)the Joint Support Program from Tropical Crop Breeding Engineering Center of Ministry of Education of China+1 种基金the Crop Science National Key Disciplines of China (lhxm-2012-2)the Key Scientific Research Program from Hainan Province,China (ZDZX2013023)
文摘Fusarium wilt of banana, which is caused by Fusarium oxysporum f. sp. cubense tropical race 4 （Foc TR4）, is a serious soil-borne fungal disease. Now, the epigenetic molecular pathogenic basis is elusive. In this study, with methylation-sensitive amplification polymorphism （MSAP） technique, DNA methylation was compared between the leaves inoculated with Foc TR4 and the mock-inoculated leaves at different pathogenic stages. With 25 pairs of primers, 1 144 and 1 255 fragments were amplified from the infected and mock-inoculated leaves, respectively. DNA methylation was both changed and the average methylated CCGG sequences were 34.81 and 29.26% for the infected and the mock-inoculated leaves. And DNA hypermethylation and hypomethylation were induced by pathogen infection during all pathogenic stages. Further, 69 polymorphic fragments were sequenced and 29 of them showed sequence similarity to genes with known functions. And RT-PCR results of four genes indicated that their expression patterns were consistent with their methylation patterns. Our results suggest that DNA methylation plays important roles in pathogenic response to Foc TR4 for banana.
基金Supported by Yunnan Science and Technology Innovation Talent Program(2015HA034)National Natural Science Foundation of China(NSFC31560505)
文摘Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense tropic race 4(Foc TR4), is a typical vascular and soil-borne disease which has significantly threatened the sustainable development of banana industry. In order to reveal the infection process and pathogenesis of Foc TR4, the young mycelia(66.7 mg/ml) of wild-type strain of Foc TR4(WT-Foc TR4) cultured for 18-20 h were lysed with enzyme mixture for protoplast formation, which consisted of 25 mg/ml driselase, 0.4 mg/ml chitinase, 15 mg/ml lysing enzyme and 1.2 mol/L potassium chloride. The resulted protoplasts of 2×10~7 cells/ml were used to test the efficiency of transformation mediated by polyethylene glycol, and up to 9 transformants per microgram of DNA were obtained. AmCyan, RFP and YFP genes were stably transferred into the WT-Foc TR4, separately, using the protoplast transformation system. The gene FoOCH1 encoding α-1, 6-mannosyltransferase in the WT-Foc TR4 was knocked out using the split-marker recombination technology. The genetic transformation and gene knockout system in this pathogen lays a foundation for the study of functional genomics and plant-pathogen interactions.
基金Supported by Major Crop Pests Monitoring,Disaster Regulation and Prevention and Control Mecha-nism Project in Yunnan Province(2018BB016)Yunling Scholar Programme of Yunnan Provincial Government,Science and Technology Innovation Talents Program in Yunnan Province(2015HA034)+1 种基金Special Project of National Banana Industry Technical System(CARS-31-08)Key Laboratory of Green Prevention and Control of Agricultural Transboundary Pests of Yunnan Province&the CGIAR Research Program on Roots,Tubers and Bananas(RTB)。
文摘[Objective]The paper was to understand the field resistance performance of different banana varieties and the prevention and control ef-fect of different fertilizers,so as to provide technical reference for the prevention and control of Fusarium wilt.[Method]Field trials were set up with three treatments:shrimp peptide organic fertilizer+shrimp peptide special protection+shrimp peptide fruit Yekang(simplified as shrimp peptide organic fertilizer treatment),conventional organic fertilizer+microbial preparations(simplified as microbial treatment),and conventional or-ganic fertilizer(simplified as control).Four different banana varieties of Brazilian banana,Guijiao No.1,Nantianhuang,and Yunjiao No.1 were se-lected for the field trial.The disease incidence of Fusarium wilt and the control effects of three fertilizers were investigated during four time periods.[Result]The disease incidence of four varieties in three treatments varied.The disease incidence of Nantianhuang and Yunjiao No.1 were signifi-cantly lower than that of other two varieties.There was also significant difference in disease incidence of three treatments.The disease incidence from high to low was control>shrimp peptide organic fertilizer treatment>microbial treatment.The average monthly TR4 pathogen content in heavily infected banana plantation was more than 2000 copies,while the highest one reached 15148.9 copies.[Conclusion]Microbial agents reduced the disease incidence of Fusarium wilt to some content.Nantianhuang and Yunjiao No.1 showed the highest disease resistance compared with other varieties.However,their resistance needs to be further improved before practical application.
基金Supported by Culture Fund of Hainan Medical College for Scientific Researchin 2013(HY2013-22)
文摘A biocontrol strain HJX1,which had good inhibitory effect against Fusarium oxysporum f. sp. cubense,was identified as Bacillus subtilis based on traditional morphology,16 S rRNA gene sequence and fatty acid profiles. The sequence of 16 S rRNA gene had 99% homology to B. subtilis according to the DNA fragment of 1 521 bp amplified with a pair of universal primers,P0 and P6,of bacteria. Confront culture with pathogenic fungi showed that this strain had good inhibitory effect against 10 pathogenic fungi.
基金Supported by the natural science foundation of Hainan Province in 2015(20158304)
文摘Bacillus subtilis HJX1, a biocontrol strain of Fusarium oxysporum f. sp. cubense, could inhibit growth of several plant pathogenic fungi in vitro. To un- derstand its mechanism of fungistasis, we extracted crude protein from fermentation broth of the strain HJX1 through ammonium sulfate precipitation, and prelimina- rily studied fungistatic activities at different conditions. The results showed that the crude protein was insensitive to protease K, trypsin or ultraviolet radiation. The fungistatic activity was unchanged when treated in water batch at 40 ℃, 60 ℃, 80 ℃ or 100 ℃ for 30 min, and the fungistatic activity maintained 60% when trea- ted at 121℃ for 30 min.
