Chemical potassium(K)fertilizer is commonly used in apple(Malus domestica L.Borkh)production but K is easily fixed by soil,resulting in reduced K ferilizer utilization and wasted resources.K-solubilizing bacteria(KSB)...Chemical potassium(K)fertilizer is commonly used in apple(Malus domestica L.Borkh)production but K is easily fixed by soil,resulting in reduced K ferilizer utilization and wasted resources.K-solubilizing bacteria(KSB)can cost-effectively increase the soluble K content in rhizosphere soil.Therefore,the objectives were to select high-efficiency KSB from apple orchards under various soil management models and evaluate their effects on apple seedling growth.Maize(Zea maysL.)straw mulching(MSM)increased the total carbon(TC),total nitrogen(TN)and available potassium(AK)in the rhizosphere and improved fruit quality.The number of KSB in the rhizosphere soil of MSM was 9.5×10×CFU g1 soil,which was considerably higher than that in the other mulching models.Fourteen KSB strains were isolated with relative K solubilizing ability ranging from 17 to 30%,and five strains increased the dry weight per apple seedling.The most eficient strain was identified as Paenibacillus mucilaginosus through morphological observation and sequence analysis of 16S rDNA,named JGK.After inoculation,the colonization of JGK in soil decreased from 4.0 to 1.5×10×CFU g^-1 soil within 28 d.The growth of the apple seedlings and the K accumulation in apple plants were promoted by irigation with 50 mL JGK bacterial solution(1×10^9 CFU mL^-1),but there was no significant increase in the AK content of rhizosphere soil.High-performance liquid phase analysis(HPLC)data showed that the JGK metabolites contained phytohormones and organic acids.Hence,the JGK strain promoted the growth of two-month-old apple seedlings by stimulating function of the produced phytohormones and enhanced K solubility by acidification for apple seedling uptake.This study enriches the understanding of KSB and provides an effective means to increase the K utilization efficiency of apple production.展开更多
[Objectives]The paper was to identify growth-promoting strains within the culturable bacterial flora of areca palm.[Methods]Culturable bacteria were isolated and identified from areca palm using samples obtained from ...[Objectives]The paper was to identify growth-promoting strains within the culturable bacterial flora of areca palm.[Methods]Culturable bacteria were isolated and identified from areca palm using samples obtained from both healthy and yellowing disease-affected plants within the same orchard.Strains that exhibited significant differences between healthy and affected samples,or that were unique to the healthy samples,were subsequently screened for their growth-promoting effects.[Results]Three bacterial strains demonstrated robust and consistent capacity for auxin production,specifically Paenibacillus,Pseudomonas aeruginosa,and Bacillus amyloliquefaciens,each yielding approximately 50μg of IAA per mL of bacterial solution.The strain Alcaligenes faecalis exhibited the highest efficacy in siderophore production,achieving 21.15%of active units.Additionally,A.faecalis,Bacillus velezensis,and P.aeruginosa were noted for their potassium-solubilizing capabilities,as evidenced by the presence of distinct potassium-solubilizing zones.[Conclusions]The evaluation of the aforementioned growth-promoting strains may offer valuable insights for the development of growth-promoting strains specifically for areca palm.展开更多
基金Supported by the National Key R&D Program ot China(2016YFD0201100)the National Natural Science Foundation of China(31701902)the earmarked fund for China Agriculture Research System(CARS-27).
文摘Chemical potassium(K)fertilizer is commonly used in apple(Malus domestica L.Borkh)production but K is easily fixed by soil,resulting in reduced K ferilizer utilization and wasted resources.K-solubilizing bacteria(KSB)can cost-effectively increase the soluble K content in rhizosphere soil.Therefore,the objectives were to select high-efficiency KSB from apple orchards under various soil management models and evaluate their effects on apple seedling growth.Maize(Zea maysL.)straw mulching(MSM)increased the total carbon(TC),total nitrogen(TN)and available potassium(AK)in the rhizosphere and improved fruit quality.The number of KSB in the rhizosphere soil of MSM was 9.5×10×CFU g1 soil,which was considerably higher than that in the other mulching models.Fourteen KSB strains were isolated with relative K solubilizing ability ranging from 17 to 30%,and five strains increased the dry weight per apple seedling.The most eficient strain was identified as Paenibacillus mucilaginosus through morphological observation and sequence analysis of 16S rDNA,named JGK.After inoculation,the colonization of JGK in soil decreased from 4.0 to 1.5×10×CFU g^-1 soil within 28 d.The growth of the apple seedlings and the K accumulation in apple plants were promoted by irigation with 50 mL JGK bacterial solution(1×10^9 CFU mL^-1),but there was no significant increase in the AK content of rhizosphere soil.High-performance liquid phase analysis(HPLC)data showed that the JGK metabolites contained phytohormones and organic acids.Hence,the JGK strain promoted the growth of two-month-old apple seedlings by stimulating function of the produced phytohormones and enhanced K solubility by acidification for apple seedling uptake.This study enriches the understanding of KSB and provides an effective means to increase the K utilization efficiency of apple production.
基金Supported by Specific Research Fund of the Innovation Platform for Academicians of Hainan Province(YSPTZX202151).
文摘[Objectives]The paper was to identify growth-promoting strains within the culturable bacterial flora of areca palm.[Methods]Culturable bacteria were isolated and identified from areca palm using samples obtained from both healthy and yellowing disease-affected plants within the same orchard.Strains that exhibited significant differences between healthy and affected samples,or that were unique to the healthy samples,were subsequently screened for their growth-promoting effects.[Results]Three bacterial strains demonstrated robust and consistent capacity for auxin production,specifically Paenibacillus,Pseudomonas aeruginosa,and Bacillus amyloliquefaciens,each yielding approximately 50μg of IAA per mL of bacterial solution.The strain Alcaligenes faecalis exhibited the highest efficacy in siderophore production,achieving 21.15%of active units.Additionally,A.faecalis,Bacillus velezensis,and P.aeruginosa were noted for their potassium-solubilizing capabilities,as evidenced by the presence of distinct potassium-solubilizing zones.[Conclusions]The evaluation of the aforementioned growth-promoting strains may offer valuable insights for the development of growth-promoting strains specifically for areca palm.
