Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with t...Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with the plants.These bacteria viz.,Agrobacterium,Arthobacter,Azospirillum,Bacillus,Burkholderia,Flavobacterium,Pseudomonas,Rhizobium,etc.,play important role in plant growth promotion.In addition,such symbiotic associations of PGPRs in the rhizospheric region also confer protection against several diseases caused by bacterial,fungal and viral pathogens.The biocontrol mechanism utilized by PGPR includes direct and indirect mechanisms direct PGPR mechanisms include the production of antibiotic,siderophore,and hydrolytic enzymes,competition for space and nutrients,and quorum sensing whereas,indirect mechanisms include rhizomicrobiome regulation via.secretion of root exudates,phytostimulation through the release of phytohormones viz.,auxin,cytokinin,gibberellic acid,1-aminocyclopropane-1-carboxylate and induction of systemic resistance through expression of antioxidant defense enzymes viz.,phenylalanine ammonia lyase(PAL),peroxidase(PO),polyphenyloxidases(PPO),superoxide dismutase(SOD),chitinase andβ-glucanases.For the suppression of plant diseases potent bio inoculants can be developed by modulating the rhizomicrobiome through rhizospheric engineering.In addition,understandings of different strategies to improve PGPR strains,their competence,colonization efficiency,persistence and its future implications should also be taken into consideration.展开更多
Climate change has remarkably intensified the occurrence offloods around the globe.Flooding causes loss of life and property.Flood frequency analysis(FFA)is an important investigation and plays a key role inflood-rela...Climate change has remarkably intensified the occurrence offloods around the globe.Flooding causes loss of life and property.Flood frequency analysis(FFA)is an important investigation and plays a key role inflood-related studies.Geographically,the study area is confined in the lower Brahmaputrafloodplains,flat slope,and rivers are braided in nature.Because of Heavy rainfall,major rivers in the area carry huge influxes of surged water during the summer period.Hence,disastrousflooding can be seen every year in the study region.The present study aims to modelflood frequency using the hydrological data to understand the effects within the area.FFA approaches like Gumbel,Log Pearson type 3(LP-3),and Log-Normal(LN)were used,and comparative analyses were done using water level data for the Manas,Aie,and Brahmaputra Rivers.Moreover,remote sensing and the geographic information system(GIS)environment were used to generate FFA-basedflood predictive inundation map at 5,10,50,100,and 200 years of return periods.Here,Gumbel's distribution has found the bestfit for all the rivers among the three.The distribution reveals that at a 200-year return period,the highest water level would be increased by 1.45,2.41,and 4 m for the Manas,Aie,and Brahmaputra Rivers,respectively.The study shows that almost 493.54 and 673.72 km^(2) of areas are expected to be submerged at 5 and 200-year return periods according to Gumbel's distribution;LP-3 distribution predicted 493.01 and 555.66 km^(2),and the log-normal distribution method predicted 432.51 and 555.74 km^(2) offlood-sensitive areas at 5 and 200-year return periods,respectively.The FFA highlighted spatio-temporal effects on the expansion of submerged areas.We hope that thefindings of the present study will aid in the differentflood hazard management strategies for future endeavors.展开更多
For establishing the favourable media for growth of Phaeoacremonium parasiticum, the fungus was inoculated in five different media (Potato Dextrose Broth (PDB), Host Extract (50%) + PDB (50%) (HE + PDB), and the solid...For establishing the favourable media for growth of Phaeoacremonium parasiticum, the fungus was inoculated in five different media (Potato Dextrose Broth (PDB), Host Extract (50%) + PDB (50%) (HE + PDB), and the solid media viz., Rice Bran (RB), Maize Meal (MM) and Wheat Bran (WB)) at pH of 6.5 and incubated at a temperature of 30℃± 1℃. The solid media were added with water at the rate of 70 ml/100g of solid substrate. After 30 days of inoculation, conidial population of P. parasiticum in liquid media was lower compared to conidial population in solid media. In solid media, MM media showed the highest conidial population (9.56 log·cfu/g) followed by WB (9.50 log·cfu/g) and RB (9.38 log·cfu/g). Hence, Maize Meal media (MM: Water = 100 g:70 ml) at pH of 6.5, incubation temperature: 30℃± 1℃for 30 days would be the standard technique for mass production of P. parasiticum.展开更多
文摘Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with the plants.These bacteria viz.,Agrobacterium,Arthobacter,Azospirillum,Bacillus,Burkholderia,Flavobacterium,Pseudomonas,Rhizobium,etc.,play important role in plant growth promotion.In addition,such symbiotic associations of PGPRs in the rhizospheric region also confer protection against several diseases caused by bacterial,fungal and viral pathogens.The biocontrol mechanism utilized by PGPR includes direct and indirect mechanisms direct PGPR mechanisms include the production of antibiotic,siderophore,and hydrolytic enzymes,competition for space and nutrients,and quorum sensing whereas,indirect mechanisms include rhizomicrobiome regulation via.secretion of root exudates,phytostimulation through the release of phytohormones viz.,auxin,cytokinin,gibberellic acid,1-aminocyclopropane-1-carboxylate and induction of systemic resistance through expression of antioxidant defense enzymes viz.,phenylalanine ammonia lyase(PAL),peroxidase(PO),polyphenyloxidases(PPO),superoxide dismutase(SOD),chitinase andβ-glucanases.For the suppression of plant diseases potent bio inoculants can be developed by modulating the rhizomicrobiome through rhizospheric engineering.In addition,understandings of different strategies to improve PGPR strains,their competence,colonization efficiency,persistence and its future implications should also be taken into consideration.
文摘Climate change has remarkably intensified the occurrence offloods around the globe.Flooding causes loss of life and property.Flood frequency analysis(FFA)is an important investigation and plays a key role inflood-related studies.Geographically,the study area is confined in the lower Brahmaputrafloodplains,flat slope,and rivers are braided in nature.Because of Heavy rainfall,major rivers in the area carry huge influxes of surged water during the summer period.Hence,disastrousflooding can be seen every year in the study region.The present study aims to modelflood frequency using the hydrological data to understand the effects within the area.FFA approaches like Gumbel,Log Pearson type 3(LP-3),and Log-Normal(LN)were used,and comparative analyses were done using water level data for the Manas,Aie,and Brahmaputra Rivers.Moreover,remote sensing and the geographic information system(GIS)environment were used to generate FFA-basedflood predictive inundation map at 5,10,50,100,and 200 years of return periods.Here,Gumbel's distribution has found the bestfit for all the rivers among the three.The distribution reveals that at a 200-year return period,the highest water level would be increased by 1.45,2.41,and 4 m for the Manas,Aie,and Brahmaputra Rivers,respectively.The study shows that almost 493.54 and 673.72 km^(2) of areas are expected to be submerged at 5 and 200-year return periods according to Gumbel's distribution;LP-3 distribution predicted 493.01 and 555.66 km^(2),and the log-normal distribution method predicted 432.51 and 555.74 km^(2) offlood-sensitive areas at 5 and 200-year return periods,respectively.The FFA highlighted spatio-temporal effects on the expansion of submerged areas.We hope that thefindings of the present study will aid in the differentflood hazard management strategies for future endeavors.
文摘For establishing the favourable media for growth of Phaeoacremonium parasiticum, the fungus was inoculated in five different media (Potato Dextrose Broth (PDB), Host Extract (50%) + PDB (50%) (HE + PDB), and the solid media viz., Rice Bran (RB), Maize Meal (MM) and Wheat Bran (WB)) at pH of 6.5 and incubated at a temperature of 30℃± 1℃. The solid media were added with water at the rate of 70 ml/100g of solid substrate. After 30 days of inoculation, conidial population of P. parasiticum in liquid media was lower compared to conidial population in solid media. In solid media, MM media showed the highest conidial population (9.56 log·cfu/g) followed by WB (9.50 log·cfu/g) and RB (9.38 log·cfu/g). Hence, Maize Meal media (MM: Water = 100 g:70 ml) at pH of 6.5, incubation temperature: 30℃± 1℃for 30 days would be the standard technique for mass production of P. parasiticum.
