• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The study of soil bacterial communities between organic The study of soil bacterial communities between organic and conventional farming in a banana field conventional farming in a banana field

Liu, Liang-yin 01 January 2013 (has links)
Abstract Based on maintaining healthy soil for sustainable agriculture and enhancing banana disease resistance, Taiwan Banana Research Institute began to conduct organic cultivation on a trial basis in 1998. It had been proved that the morbidity of banana Fusarial wilt disease at organic cultivation plots was significantly lower than that of conventional farming. In order to study the differences of soil microbiota between the organic cultivation plots and the conventional farming areas, physical and chemical properties of the rhizosphere and non- rhizosphere soil samples were assayed during the period of Aug. 2010 to May 2011. The bacterial diversity was analyzed by molecular biology methods, including PCR-DGGE to separate the 16S rDNA V6 ~ V8 region of various bacteria and the recombinant DNA technology by using pGEM-T Easy Vector System to separate and sequence the DNA fragments. The results showed that organic plots was loam soil, but the conventional farming soil was sandy loam with higher sand content. The soil pH in 13 years organic area was mildly alkaline, but in conventional farming area was mildly acidic to slightly acidic. The content of various nutrients in organic 13-year area soil was not necessarily higher than the conventional farming area soil. The available nutrient contents in organic areas trend to be more stable than that in the conventional areas. Fertilization may affect the content of available nutrients in the soil. No bacterial DNA could be extracted from the organic fertilizer. The bacterial microbiota in soil was very stable, and was not related to the sampling seasons. The Banana strains had little effect on soil bacterial microbiota. There was no difference on the bacterial microbiota between the rhizosphere and non-rhizosphere soil samples. It is not sure whether there were any differences on the bacterial microbiota between the nearby soil of banana Fusarial wilt plants and the nearby soil of the healthy plants. By analyzing the DNA fragment clone library, 43 strains correspond to known category, of which 28 belonged to the Proteobacteria, and 34 were uncultured strains. The role of these microbial strains might involve in various element cycles, such as N cycles, C cycles, and S cycles (including some photosynthetic bacteria). The systematic cladogram showed that organic 13-year areas, organic 3-year areas and conventional farming areas represented three major categaries. The organic 13-year area and conventional area possessed the highest difference on the microbiota composition.

Page generated in 0.0856 seconds