对分离自玉米植株的内生细菌R-4进行鉴定,测试其对玉米南方锈病(SCR)的防病增产效果。用盆栽方法测定菌株R-4对玉米植株的促生效果,根据16S r DNA序列对菌株R-4进行鉴定,采用自然发病方式测试其对SCR的防病增产效果。结果表明,菌株R-4...对分离自玉米植株的内生细菌R-4进行鉴定,测试其对玉米南方锈病(SCR)的防病增产效果。用盆栽方法测定菌株R-4对玉米植株的促生效果,根据16S r DNA序列对菌株R-4进行鉴定,采用自然发病方式测试其对SCR的防病增产效果。结果表明,菌株R-4处理玉米的发芽率、播种后18 d株高、播种后28 d株高、植株地上部干重及根干重比对照分别增加17.19%、32.03%、41.80%、92.53%和37.03%。通过16S r DNA序列分析,将菌株R-4鉴定为蜡样芽孢杆菌(Bacillus cereus)。菌株R-4在先玉335、银糯1号、浚单20上对SCR的防效达39.2%~92.1%(平均为65.7%),经该菌处理后玉米增产2.58%~9.02%(平均为6.66%)。展开更多
以道地产地高良姜为材料,对该药用植物内生细菌种群组成、组织分布及其促生潜力进行了研究。采用组织块分离法,从高良姜根、根茎、茎和叶4个组织共计分离得到细菌136株,分属于16个16S r DNA基因型、12个细菌属、15个细菌种,其中,芽孢杆...以道地产地高良姜为材料,对该药用植物内生细菌种群组成、组织分布及其促生潜力进行了研究。采用组织块分离法,从高良姜根、根茎、茎和叶4个组织共计分离得到细菌136株,分属于16个16S r DNA基因型、12个细菌属、15个细菌种,其中,芽孢杆菌、甲基杆菌分别为其最、次优势种群。各种群分离比随组织不同而异;采用Hha I消化的末端限制性片段多态性(TRFLP)免培养方法,从高良姜4个组织共计检测到36个不同的末端限制性酶切片段(T-RFs)。种群对应分析表明其免培养内生细菌群体主要包括芽孢杆菌、甲基杆菌等高抗性细菌,海洋螺菌、红杆菌、交替假单胞菌等海洋细菌及热带根瘤菌、沼泽考克氏菌等热带相关细菌,说明高良姜内生细菌群体与其宿主植物生长环境密切相关。不同组织其总T-RFs数目、优势T-RFs及其对应细菌种群明显不同;在所分离的细菌菌株中,36.36%、51.52%、54.55%和27.27%的菌株分别显示了胞外几丁质酶、β-葡聚糖酶,生长素及其1-氨基环丙烷-1-羧酸(ACC)脱氨酶产生能力。其中,泛菌L-2、芽孢杆菌S-16所测4个指标均为阳性,热带根瘤菌菌株R-1和R-3显示了较高的ACC脱氨酶及生长素产生能力,这些菌株是促生菌剂的良好候选。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
文摘对分离自玉米植株的内生细菌R-4进行鉴定,测试其对玉米南方锈病(SCR)的防病增产效果。用盆栽方法测定菌株R-4对玉米植株的促生效果,根据16S r DNA序列对菌株R-4进行鉴定,采用自然发病方式测试其对SCR的防病增产效果。结果表明,菌株R-4处理玉米的发芽率、播种后18 d株高、播种后28 d株高、植株地上部干重及根干重比对照分别增加17.19%、32.03%、41.80%、92.53%和37.03%。通过16S r DNA序列分析,将菌株R-4鉴定为蜡样芽孢杆菌(Bacillus cereus)。菌株R-4在先玉335、银糯1号、浚单20上对SCR的防效达39.2%~92.1%(平均为65.7%),经该菌处理后玉米增产2.58%~9.02%(平均为6.66%)。
文摘以道地产地高良姜为材料,对该药用植物内生细菌种群组成、组织分布及其促生潜力进行了研究。采用组织块分离法,从高良姜根、根茎、茎和叶4个组织共计分离得到细菌136株,分属于16个16S r DNA基因型、12个细菌属、15个细菌种,其中,芽孢杆菌、甲基杆菌分别为其最、次优势种群。各种群分离比随组织不同而异;采用Hha I消化的末端限制性片段多态性(TRFLP)免培养方法,从高良姜4个组织共计检测到36个不同的末端限制性酶切片段(T-RFs)。种群对应分析表明其免培养内生细菌群体主要包括芽孢杆菌、甲基杆菌等高抗性细菌,海洋螺菌、红杆菌、交替假单胞菌等海洋细菌及热带根瘤菌、沼泽考克氏菌等热带相关细菌,说明高良姜内生细菌群体与其宿主植物生长环境密切相关。不同组织其总T-RFs数目、优势T-RFs及其对应细菌种群明显不同;在所分离的细菌菌株中,36.36%、51.52%、54.55%和27.27%的菌株分别显示了胞外几丁质酶、β-葡聚糖酶,生长素及其1-氨基环丙烷-1-羧酸(ACC)脱氨酶产生能力。其中,泛菌L-2、芽孢杆菌S-16所测4个指标均为阳性,热带根瘤菌菌株R-1和R-3显示了较高的ACC脱氨酶及生长素产生能力,这些菌株是促生菌剂的良好候选。
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.
