Effect of Long-term Fertilizers Application on Rhizosphere Fluorescent Pseudomonas

• Main Authors: Chen-Ying Chang, 張臻潁
• Other Authors: 施養信
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/37337605434787115961

博士 === 國立中興大學 === 土壤環境科學系所 === 96 === The genetic and functional diversities of rhizosphere fluorescent Pseudomonas were both assayed to detect the effect of long-term fertilizer application. Soil samples were collected from an expermental field in Taichung County that had been applied hog-dung compost or chemical fertilizers for six years, and soil that without any applicaiton was also collected as the control treatment. Soil samples were used for the pot culture for maize or rice in labortory. Each plant was cultured with three different treatments of compost, chemical fertilizer and control, and four replicates were set for each treatment. After compost application for six years, the soil pH, organic content and the organic carbon content were significant higher (P<0.05) than the control soil. After the long-term chemical fertilizer applicaiton, few maize rhizosphere fluorescent Pseudomonas isolates revealed different Biolog GN plates substrate utilization patterns from isolates of the other two treatments. This indicated that the substrate utilization patterns of fluorescent Pseudomonas isolates were shifted after long-term chemical fertilizer application. After the long-term compost application, the fluorescent Pseudomonas community in maize rhizosphere consisted of Pseudomonas putida (61%) and Pseudomonas hibiscicola (30%), while that in control treatment was mostly consisted of P. putida (80%). This indicated the long-term compost application effect on fluorescent Pseudomonas community structure. P. putida isolates of compost treatment revealed similar carbohydrateds utilization ability to P. putida isolate of control treatment. However, P. putida of compost treatment revealed significant higher (P<0.05) utilization ability of i-erythritol and L-rhamnose than P. putida isolates of control treament. P. putida isolates of control treatment revealed significant (P<0.05) higher utilization ability of carboxylic acids, such as cis-aconitic acid, citric acid and formic acid, than P. putida isolates of compost treatment. This indicated different metabolic patterns between same species isolates after long-term compost application. The result of pot culture of rice plant found that some isolates of compost treatment revealed same 16S rDNA RFLP patterns with some isolates of chemical fertilizers, however, different metabolic patterns were found among isolates. Few isolates of chemical fertilizer treatment revealed similar metabolic patterns of isolates of control treatment, however, different genetic patterns were revealed among those isolates. This indicated that the effect of long-term chemical fertilizer applicaiton on metabolic pattern of fluorescent Pseudomonas in rice rhizosphere was similiar to that of control treatment. And long-term compost application resulted in a shift of metabolic patterns of fluorescent Pseudomonas in rice rhiosphere. 16S-23S rDNA RFLP method was used for analysis of 11 fluorescent Pseudomonas isolates of maize rhizosphere in this study. Different patterns were revealed among isolates that belong to different sub-species. This indicated that 16S-23S rDNA RFLP method was able to identify rhizosphere fluorescent Pseudomonas in a high resolution level, and this method was sutible to be used for the fast analysis of rhizosphere fluorescent Pseudomonas isolates.