ObjectiveThis study aimed to investigate the promoting effect of mycorrhizal fungi inoculation on growth of Pinus bungeana. MethodPinus bungeana young trees and ancient trees were inoculated with different doses of Pi...ObjectiveThis study aimed to investigate the promoting effect of mycorrhizal fungi inoculation on growth of Pinus bungeana. MethodPinus bungeana young trees and ancient trees were inoculated with different doses of Pisolithus tinctorius, to investigate the effect on Pinus bungeana growth. ResultAfter inoculated with Pisolithus tinctorius, the mycorrhizal infection rate in roots of Pinus bungeana young trees and ancient trees increased significantly; mycorrhizal infection rate of Pinus bungeana young trees was enhanced with the increasing dose of Pisolithus tinctorius; mycorrhizal fungi inoculation could significantly promote the growth of Pinus bungeana ancient trees, which also had significant promoting effect on the plant height of Pinus bungeana young trees but had no significant effect on the diameter at breast height; in addition, mycorrhizal fungi inoculation could promote the absorption of nitrogen and phosphorus by Pinus bungeana young trees. ConclusionThis study provided technical support for the cultivation of Pinus bungeana in the south of China.展开更多
Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soi...Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi (AMF) are universal and ubiquitous rhizosphere mi-croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal (HM) contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial bio-technology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation.展开更多
Application of plant growth-promoting rhizobacteria （PGPR） has been shown to increase legume growth and development under field and controlled environmental conditions. The present study was conducted to isolate pla...Application of plant growth-promoting rhizobacteria （PGPR） has been shown to increase legume growth and development under field and controlled environmental conditions. The present study was conducted to isolate plant growth-promoting rhizobacteria （PGPR） from the root nodules of lentil （Lens culinaris Medik.） grown in arid/semi-arid region of Punjab, Pakistan and examined their plant growth-promoting abilities. Five bacterial isolates were isolated, screened in vitro for plant growth-promoting （PGP） characteristics and their effects on the growth of lentil were assessed under in vitro, hydroponic and greenhouse （pot experiment） conditions. All the isolates were Gram negative, rod-shaped and circular in form and exhibited the plant growth-promoting attributes of phosphate solubilization and auxin （indole acetic acid, IAA） production. The IAA production capacity ranged in 0.5-11.0μg mL-1 and P solubilization ranged in 3-16 mg L-1. When tested for their effects on plant growth, the isolated strains had a stimulatory effect on growth, nodulation and nitrogen （N） and phosphorus （P） uptake in plants on nutrient-deficient soil. In the greenhouse pot experiment, application of PGPR significantly increased shoot length, fresh weight and dry weight by 65%, 43% and 63% and the increases in root length, fresh weight and dry weight were 74%, 54% and 92%, respectively, as compared with the uninoculated control. The relative increases in growth characteristics under in vitro and hydroponic conditions were even higher. PGPR also increased the number of pods per plant, 1 000-grain weight, dry matter yield and grain yield by 50%, 13%, 2870 and 29%, respectively, over the control. The number of nodules and nodule dry mass increased by 170% and 136%, respectively. After inoculation with effective bacterial strains, the shoot, root and seed N and P contents increased, thereby increasing both N and P uptake in plants. The root elongation showed a positive correlation （R2 = 0.67） with the IAA production and seed yield exhibited a positive correlation （R2 = 0.82） with root nodulation. These indicated that the isolated PGPR rhizobial strains can be best utilized as potential agents or biofertilizers for stimulating the growth and nutrient accumulation of lentil.展开更多
Plant growth-promoting rhizobacteria （PGPR） have been widely recognized as an important agent, especially as a biofertilizer, in agricultural systems. The objectives of this study were to select effective PGPR for C...Plant growth-promoting rhizobacteria （PGPR） have been widely recognized as an important agent, especially as a biofertilizer, in agricultural systems. The objectives of this study were to select effective PGPR for Chinese kale （Brassica oleracea var. alboglabra） cultivation and to investigate the effect of their inoculation on indigenous microbial community structure. The Bacillus sp. SUT1 and Pseudomonas sp. SUT19 were selected for determining the efficiency in promoting Chinese kale growth in both pot and field experiments. In the field experiment, PGPR amended with compost gave the highest yields among all treatments. The Chinese kale growth promotion may be directly affected by PGPR inoculation. The changes of microbial community structure in the rhizosphere of Chinese kale following PGPR inoculation were examined by denaturing gradient gel electrophoresis （DGGE） and principal coordinate analysis. The DGGE fingerprints of 16S rDNA amplified from total community DNA in the rhizosphere confirmed that our isolates were established in the rhizosphere throughout this study. The microbial community structures were slightly different among all the treatments, and the major changes depended on stages of plant growth. DNA sequencing of excised DGGE bands showed that the dominant species in microbial community structure in the rhizosphere were not mainly interfered by PGPR, but strongly influenced by plant development. The microbial diversity as revealed by diversity indices was not different between the PGPR-inoculated and uninoculated treatments. In addition, the rhizosphere soil had more influence on eubacterial diversity, whereas it did not affect archaebacterial and fungal diversities.展开更多
Plants are frequently exposed to adverse environments during their life span.Among them drought stress is one of the major threats to agricultural productivity.In order to survive in such unstable environment,plants h...Plants are frequently exposed to adverse environments during their life span.Among them drought stress is one of the major threats to agricultural productivity.In order to survive in such unstable environment,plants have developed mechanisms through which they recognize the severity of the stress based on the incoming environmental stimuli.To combat the detrimental effects of drought,the plants have evolved various strategies to modulate their physio-hormonal attributes.These strategies that can be modulated by shade and microbes contribute to enhancing tolerance to drought and reducing yield loss.Plant hormones,such as abscisic acid,auxin and ethylene have a major role in the shade-and microbe-associated improvement of drought tolerance through their effects on various metabolic pathways.In this process,the CLAVATA3/EMBRYOSURROUNDING REGION-RELATED 25 peptide has a major role due to its effect on ABA synthesis as shown in our regulatory model.展开更多
基金Supported by Project of Shanghai Municipal Agricultural Commission[HNKTZ(2008)NO.6-1]~~
文摘ObjectiveThis study aimed to investigate the promoting effect of mycorrhizal fungi inoculation on growth of Pinus bungeana. MethodPinus bungeana young trees and ancient trees were inoculated with different doses of Pisolithus tinctorius, to investigate the effect on Pinus bungeana growth. ResultAfter inoculated with Pisolithus tinctorius, the mycorrhizal infection rate in roots of Pinus bungeana young trees and ancient trees increased significantly; mycorrhizal infection rate of Pinus bungeana young trees was enhanced with the increasing dose of Pisolithus tinctorius; mycorrhizal fungi inoculation could significantly promote the growth of Pinus bungeana ancient trees, which also had significant promoting effect on the plant height of Pinus bungeana young trees but had no significant effect on the diameter at breast height; in addition, mycorrhizal fungi inoculation could promote the absorption of nitrogen and phosphorus by Pinus bungeana young trees. ConclusionThis study provided technical support for the cultivation of Pinus bungeana in the south of China.
文摘Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi (AMF) are universal and ubiquitous rhizosphere mi-croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal (HM) contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial bio-technology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation.
基金Supported by the University of Azad Jammu and Kashmir, Pakistan and the Pakistan Agriculture Research Council, Pakistan (No. ALP NR-27)
文摘Application of plant growth-promoting rhizobacteria （PGPR） has been shown to increase legume growth and development under field and controlled environmental conditions. The present study was conducted to isolate plant growth-promoting rhizobacteria （PGPR） from the root nodules of lentil （Lens culinaris Medik.） grown in arid/semi-arid region of Punjab, Pakistan and examined their plant growth-promoting abilities. Five bacterial isolates were isolated, screened in vitro for plant growth-promoting （PGP） characteristics and their effects on the growth of lentil were assessed under in vitro, hydroponic and greenhouse （pot experiment） conditions. All the isolates were Gram negative, rod-shaped and circular in form and exhibited the plant growth-promoting attributes of phosphate solubilization and auxin （indole acetic acid, IAA） production. The IAA production capacity ranged in 0.5-11.0μg mL-1 and P solubilization ranged in 3-16 mg L-1. When tested for their effects on plant growth, the isolated strains had a stimulatory effect on growth, nodulation and nitrogen （N） and phosphorus （P） uptake in plants on nutrient-deficient soil. In the greenhouse pot experiment, application of PGPR significantly increased shoot length, fresh weight and dry weight by 65%, 43% and 63% and the increases in root length, fresh weight and dry weight were 74%, 54% and 92%, respectively, as compared with the uninoculated control. The relative increases in growth characteristics under in vitro and hydroponic conditions were even higher. PGPR also increased the number of pods per plant, 1 000-grain weight, dry matter yield and grain yield by 50%, 13%, 2870 and 29%, respectively, over the control. The number of nodules and nodule dry mass increased by 170% and 136%, respectively. After inoculation with effective bacterial strains, the shoot, root and seed N and P contents increased, thereby increasing both N and P uptake in plants. The root elongation showed a positive correlation （R2 = 0.67） with the IAA production and seed yield exhibited a positive correlation （R2 = 0.82） with root nodulation. These indicated that the isolated PGPR rhizobial strains can be best utilized as potential agents or biofertilizers for stimulating the growth and nutrient accumulation of lentil.
基金Supported by the Suranaree University of Technology and the Higher Education Research Promotionthe National Research University Project of Thailand,Office of the Higher Education Commission
文摘Plant growth-promoting rhizobacteria （PGPR） have been widely recognized as an important agent, especially as a biofertilizer, in agricultural systems. The objectives of this study were to select effective PGPR for Chinese kale （Brassica oleracea var. alboglabra） cultivation and to investigate the effect of their inoculation on indigenous microbial community structure. The Bacillus sp. SUT1 and Pseudomonas sp. SUT19 were selected for determining the efficiency in promoting Chinese kale growth in both pot and field experiments. In the field experiment, PGPR amended with compost gave the highest yields among all treatments. The Chinese kale growth promotion may be directly affected by PGPR inoculation. The changes of microbial community structure in the rhizosphere of Chinese kale following PGPR inoculation were examined by denaturing gradient gel electrophoresis （DGGE） and principal coordinate analysis. The DGGE fingerprints of 16S rDNA amplified from total community DNA in the rhizosphere confirmed that our isolates were established in the rhizosphere throughout this study. The microbial community structures were slightly different among all the treatments, and the major changes depended on stages of plant growth. DNA sequencing of excised DGGE bands showed that the dominant species in microbial community structure in the rhizosphere were not mainly interfered by PGPR, but strongly influenced by plant development. The microbial diversity as revealed by diversity indices was not different between the PGPR-inoculated and uninoculated treatments. In addition, the rhizosphere soil had more influence on eubacterial diversity, whereas it did not affect archaebacterial and fungal diversities.
基金This work was supported by the National Research,Development and Innovation Office(grant no.K131638)National Natural Science Foundation of China(grant nos.31871552,31671445)Sichuan Science and Technology Program(grant no.2018HH0108).
文摘Plants are frequently exposed to adverse environments during their life span.Among them drought stress is one of the major threats to agricultural productivity.In order to survive in such unstable environment,plants have developed mechanisms through which they recognize the severity of the stress based on the incoming environmental stimuli.To combat the detrimental effects of drought,the plants have evolved various strategies to modulate their physio-hormonal attributes.These strategies that can be modulated by shade and microbes contribute to enhancing tolerance to drought and reducing yield loss.Plant hormones,such as abscisic acid,auxin and ethylene have a major role in the shade-and microbe-associated improvement of drought tolerance through their effects on various metabolic pathways.In this process,the CLAVATA3/EMBRYOSURROUNDING REGION-RELATED 25 peptide has a major role due to its effect on ABA synthesis as shown in our regulatory model.
