Bacillus subtilis （B. subtilis） and Pseudomonas fluorescens （P. fluorescens） are two of the most important plant growth promoting rhizobacteria （PGPR） in agriculture. An in situ trial was conducted on greenhouse...Bacillus subtilis （B. subtilis） and Pseudomonas fluorescens （P. fluorescens） are two of the most important plant growth promoting rhizobacteria （PGPR） in agriculture. An in situ trial was conducted on greenhouse tomato （Lycopersicum esculentum Mill.） to examine the effect of two bacterial strains, Bacillus subtilis （CGMCC 1.3343） and Pseudomonas fluorescens （CGMCC 1.1802）, on tomato growth, gray mold disease control, catabolic and genetic microbial features of indigenous rhizosphere bacteria under lownitrogen conditions. A commercial inoculant （ETS） was also tested as a comparison. Both B. subtilis and P. fluorescens promoted growth and biomass of seedlings, while only B. subtilis was efficient in reducing gray mold incidence in greenhouse tomato. The two bacterial strains could colonization in tomato rhizosphere soil at the end of experiment （10 days after the last inoculation）. Different AWCD trends and DGGE patterns were got in different bacterial treatments; however, analyses of microbial diversities showed that indigenous soil microbes did not seem to have significant differences at either the catabolic or genetic level among treatments. ETS, as a commercial microbial agent, promoted plant growth and gave a higher microbial diversity in rhizosphere soil.展开更多
A field experiment was conducted to elucidate the regulation mechanism of different irrigation schedules on population photosynthetic of winter wheat. The experiment included five irrigation schedules, such as no irri...A field experiment was conducted to elucidate the regulation mechanism of different irrigation schedules on population photosynthetic of winter wheat. The experiment included five irrigation schedules, such as no irrigation （W0）, irrigation once at jointing （W1j） or at booting （W1b）, irrigation twice at jointing and booting （W2）, and irrigation three times at jointing, booting and grain-filling （W3） and three planting densities, such as 180 （D1）, 300 （D2） and 450 （D3） seedlings per square meter. The results indicated that irrigation significantly improved population photosynthesis. The relationship between population photosynthesis and irrigation time/volume was to some extent parabolic. Improvements in population photosynthesis （resulting from more irrigation time/volume） were mainly related to increase in leaf area index and population light interception. Population photosynthesis exhibited a significantly negative correlation with canopy light transmittance. Population photosynthesis at grain filling stage was significantly positively correlated with dry matter accumulation at post-anthesis and grain yield. Main effects and partial correlation analysis showed that population photosynthesis of W0, W1j, W1b and W3 were regulated by canopy light transmittance and leaf area. On the other hand, population photosynthesis of W2 was mainly influenced by flag leaf photosynthetic rate. On this basis, planting 300 seedlings per square meter was the optimum combination. The combination of W2D2 increased population photosynthesis during mid-late growth stages and extended high population photosynthesis duration, which ultimately increased grain yield.展开更多
基金Supported by the National High-tech Research and Development Program of China(2013AA102903)
文摘Bacillus subtilis （B. subtilis） and Pseudomonas fluorescens （P. fluorescens） are two of the most important plant growth promoting rhizobacteria （PGPR） in agriculture. An in situ trial was conducted on greenhouse tomato （Lycopersicum esculentum Mill.） to examine the effect of two bacterial strains, Bacillus subtilis （CGMCC 1.3343） and Pseudomonas fluorescens （CGMCC 1.1802）, on tomato growth, gray mold disease control, catabolic and genetic microbial features of indigenous rhizosphere bacteria under lownitrogen conditions. A commercial inoculant （ETS） was also tested as a comparison. Both B. subtilis and P. fluorescens promoted growth and biomass of seedlings, while only B. subtilis was efficient in reducing gray mold incidence in greenhouse tomato. The two bacterial strains could colonization in tomato rhizosphere soil at the end of experiment （10 days after the last inoculation）. Different AWCD trends and DGGE patterns were got in different bacterial treatments; however, analyses of microbial diversities showed that indigenous soil microbes did not seem to have significant differences at either the catabolic or genetic level among treatments. ETS, as a commercial microbial agent, promoted plant growth and gave a higher microbial diversity in rhizosphere soil.
基金Supported by China and CAS Main Direction Program of Knowledge Innovation (KSCX2-EW-B-1)China and CAS Knowledge Innovation Project(KSCX1-YW-09-06)
文摘A field experiment was conducted to elucidate the regulation mechanism of different irrigation schedules on population photosynthetic of winter wheat. The experiment included five irrigation schedules, such as no irrigation （W0）, irrigation once at jointing （W1j） or at booting （W1b）, irrigation twice at jointing and booting （W2）, and irrigation three times at jointing, booting and grain-filling （W3） and three planting densities, such as 180 （D1）, 300 （D2） and 450 （D3） seedlings per square meter. The results indicated that irrigation significantly improved population photosynthesis. The relationship between population photosynthesis and irrigation time/volume was to some extent parabolic. Improvements in population photosynthesis （resulting from more irrigation time/volume） were mainly related to increase in leaf area index and population light interception. Population photosynthesis exhibited a significantly negative correlation with canopy light transmittance. Population photosynthesis at grain filling stage was significantly positively correlated with dry matter accumulation at post-anthesis and grain yield. Main effects and partial correlation analysis showed that population photosynthesis of W0, W1j, W1b and W3 were regulated by canopy light transmittance and leaf area. On the other hand, population photosynthesis of W2 was mainly influenced by flag leaf photosynthetic rate. On this basis, planting 300 seedlings per square meter was the optimum combination. The combination of W2D2 increased population photosynthesis during mid-late growth stages and extended high population photosynthesis duration, which ultimately increased grain yield.
