The present study deals with colonization potential of plant growth promoting bacterial strains (Ochrobactrum intermedium, Bacillus cereus and Brevibacterium sp.) on Vigna radiata roots. The roots were heavily coloniz...The present study deals with colonization potential of plant growth promoting bacterial strains (Ochrobactrum intermedium, Bacillus cereus and Brevibacterium sp.) on Vigna radiata roots. The roots were heavily colonized with O. intermedium and B. cereus as compared to Brevibacterium sp. O. intermedium mainly colonized rhizoplane while B. cereus occurred both on the rhizoplane and near root zone. O. intermedium and B. cereus were found to be present both on the rhizoplane and near root zone, while Brevibacterium only in the rhizosphere in the form of groups. The cells of B. cereus were found more in the sites where root exudates were existed. From the above results it was observed that the number of O. intermedium cells were large at root exudate site. Fig 2, Tab 1, Ref展开更多
In Pakistan, particularly in Punjab Province, it is difficult for agrofarmers to combine their indigenous knowledge and modern scientific methods to evaluate existing traditional farming systems and forestry practices...In Pakistan, particularly in Punjab Province, it is difficult for agrofarmers to combine their indigenous knowledge and modern scientific methods to evaluate existing traditional farming systems and forestry practices. This requires an evaluation of indigenous soil classification in simple terms along with knowledge of the local flora, especially trees. This study focuses on land suitability classification for trees in the Attock District of Punjab, Pakistan. A survey was conducted which included interviews of local agrofarmers as well as standard soil analyses including both chemical and physical determinations of local soil types. An evaluation of soil types for cultivation of various crops was carried out given its total extent, component soil series and their proportions, spotting characteristics of each soil series and their major limitations/hazards for trees/crops. These would lead to the identification of various tree species according to soil characteristics. Then, according to the soil types and species, a land suitability map was obtained for the choice of tree species by using geographic information system （GIS） software. Land suitability classification will help local agroforesters/agrofarmers in matching suitable agricultural trees/crops properly for different soils in the area.展开更多
The screening of plant growth promoting rhizobacteria is a crucial step for their utilization as beneficial input in improving the crop productivity. This study was carried out to screen and evaluate the auxin produci...The screening of plant growth promoting rhizobacteria is a crucial step for their utilization as beneficial input in improving the crop productivity. This study was carried out to screen and evaluate the auxin producing rhizospheric isolated Pseudomonas strains for their potential to improve growth of Triticum aestivum (wheat) plant under laboratory and natural conditions. Three strains PNS-4, PNS-6 and PNS-15 were evaluated for auxin production by Salkowski’s method and further confirmed by high performance liquid chromatography (HPLC). The PNS-4, PNS-6 and PNS-15 strains were identified by I6S rRNA gene sequencing that showed maximum resemblance with Pseudomonas mendocina (99%), Pseudomonas alcaliphila (99%) and Pseudomonas sp. (99%) respectively. Selected strains were found to produce auxin with and without the amendment of exogenously applied L-tryptophan, a major precursor for auxin biosynthesis and an important constituent of plant root exudates. Efficacy of these strains on wheat plant growth was checked under laboratory and field conditions. All Pseudomonas species were found to improve the % seed germination and growth parameters (shoot length, root length, fresh weight and dry weight) of the wheat seedlings significantly (P = 0.05) as compared to the un-inoculated seedlings under laboratory condition. The biochemical parameters (total soluble protein content and endogenous auxin content) of the bacterial inoculated wheat seedling were also increased significantly than that of uninoculated ones. Under natural condition, seed bacterization also showed the significant effect (P = 0.05) on yield parameters (shoot length, number of tillers, spike length and weight of seeds in grams) of the wheat plants when compared with non-inoculated plants. Our results reported the three most promising Pseudomonas candidates and revealed the fact that experiments under laboratory and natural conditions may be helpful in selecting the best candidates as bio fertilizers for future agricultural practices.展开更多
BACKGROUND： Microbes affect the growth of plants. In this study, the diversity and plant growth-supporting activities of wheat rhizospheric bacteria were examined. METHODS： Sampling was performed thrice at different...BACKGROUND： Microbes affect the growth of plants. In this study, the diversity and plant growth-supporting activities of wheat rhizospheric bacteria were examined. METHODS： Sampling was performed thrice at different phases of plant growth. Microbes associated with the rhizoplane of three wheat varieties （Seher, Lasani, and Faisalabad） were cultured and assessed for their plant growth-promoting abilities based on auxin production, hydrogen cyanide production, phosphate solubilization, and nitrogen fixation. RESULTS： Bacterial load （CFU/mL） declined, and the succession of bacterial diversity occurred as the plants aged. Most auxin-producing bacteria and the highest concentrations of auxin （77 ~tg/mL） were observed during the second sampling point at the filleting stage. The Seher variety harbored the most auxin-producing as well as phosphate-solubilizing bacteria. Most of the bacteria belonged to Bacillus and Pseudomonas. Planomicrobium, Serratia, Rhizobium, Brevundimonas, Stenotropho- monas, and Exiguobacterium sp. were also found. CONCLUSIONS： These results suggest that the rhizoplane microbiota associated with higher-yield plant varieties have better plant growth-promoting abilities as compared to the microbiota associated with lower-yield plant varieties.展开更多
文摘The present study deals with colonization potential of plant growth promoting bacterial strains (Ochrobactrum intermedium, Bacillus cereus and Brevibacterium sp.) on Vigna radiata roots. The roots were heavily colonized with O. intermedium and B. cereus as compared to Brevibacterium sp. O. intermedium mainly colonized rhizoplane while B. cereus occurred both on the rhizoplane and near root zone. O. intermedium and B. cereus were found to be present both on the rhizoplane and near root zone, while Brevibacterium only in the rhizosphere in the form of groups. The cells of B. cereus were found more in the sites where root exudates were existed. From the above results it was observed that the number of O. intermedium cells were large at root exudate site. Fig 2, Tab 1, Ref
文摘In Pakistan, particularly in Punjab Province, it is difficult for agrofarmers to combine their indigenous knowledge and modern scientific methods to evaluate existing traditional farming systems and forestry practices. This requires an evaluation of indigenous soil classification in simple terms along with knowledge of the local flora, especially trees. This study focuses on land suitability classification for trees in the Attock District of Punjab, Pakistan. A survey was conducted which included interviews of local agrofarmers as well as standard soil analyses including both chemical and physical determinations of local soil types. An evaluation of soil types for cultivation of various crops was carried out given its total extent, component soil series and their proportions, spotting characteristics of each soil series and their major limitations/hazards for trees/crops. These would lead to the identification of various tree species according to soil characteristics. Then, according to the soil types and species, a land suitability map was obtained for the choice of tree species by using geographic information system （GIS） software. Land suitability classification will help local agroforesters/agrofarmers in matching suitable agricultural trees/crops properly for different soils in the area.
文摘The screening of plant growth promoting rhizobacteria is a crucial step for their utilization as beneficial input in improving the crop productivity. This study was carried out to screen and evaluate the auxin producing rhizospheric isolated Pseudomonas strains for their potential to improve growth of Triticum aestivum (wheat) plant under laboratory and natural conditions. Three strains PNS-4, PNS-6 and PNS-15 were evaluated for auxin production by Salkowski’s method and further confirmed by high performance liquid chromatography (HPLC). The PNS-4, PNS-6 and PNS-15 strains were identified by I6S rRNA gene sequencing that showed maximum resemblance with Pseudomonas mendocina (99%), Pseudomonas alcaliphila (99%) and Pseudomonas sp. (99%) respectively. Selected strains were found to produce auxin with and without the amendment of exogenously applied L-tryptophan, a major precursor for auxin biosynthesis and an important constituent of plant root exudates. Efficacy of these strains on wheat plant growth was checked under laboratory and field conditions. All Pseudomonas species were found to improve the % seed germination and growth parameters (shoot length, root length, fresh weight and dry weight) of the wheat seedlings significantly (P = 0.05) as compared to the un-inoculated seedlings under laboratory condition. The biochemical parameters (total soluble protein content and endogenous auxin content) of the bacterial inoculated wheat seedling were also increased significantly than that of uninoculated ones. Under natural condition, seed bacterization also showed the significant effect (P = 0.05) on yield parameters (shoot length, number of tillers, spike length and weight of seeds in grams) of the wheat plants when compared with non-inoculated plants. Our results reported the three most promising Pseudomonas candidates and revealed the fact that experiments under laboratory and natural conditions may be helpful in selecting the best candidates as bio fertilizers for future agricultural practices.
文摘BACKGROUND： Microbes affect the growth of plants. In this study, the diversity and plant growth-supporting activities of wheat rhizospheric bacteria were examined. METHODS： Sampling was performed thrice at different phases of plant growth. Microbes associated with the rhizoplane of three wheat varieties （Seher, Lasani, and Faisalabad） were cultured and assessed for their plant growth-promoting abilities based on auxin production, hydrogen cyanide production, phosphate solubilization, and nitrogen fixation. RESULTS： Bacterial load （CFU/mL） declined, and the succession of bacterial diversity occurred as the plants aged. Most auxin-producing bacteria and the highest concentrations of auxin （77 ~tg/mL） were observed during the second sampling point at the filleting stage. The Seher variety harbored the most auxin-producing as well as phosphate-solubilizing bacteria. Most of the bacteria belonged to Bacillus and Pseudomonas. Planomicrobium, Serratia, Rhizobium, Brevundimonas, Stenotropho- monas, and Exiguobacterium sp. were also found. CONCLUSIONS： These results suggest that the rhizoplane microbiota associated with higher-yield plant varieties have better plant growth-promoting abilities as compared to the microbiota associated with lower-yield plant varieties.
