The Impact of Wheat Rhizosphere on the Distribution of Burkholderia spp and Soil Bacteria

الملخص

This study was conducted on the effect of the wheat rhizosphere on the distribution of Burkholderia spp. and soil bacteria communities during wheat plant growth by the enumeration on plates of rhizosphere and non rhizosphere soil communities in different type of soils, which were collected from different fields, Wadi Elrabie and Janzour (East and west) of Tripoli, Libya. The results showed that the gram negative species of soil bacteria exceeded the remaining bacterial population in the rhizosphere on contrast with non-rhizosphere which dominance of gram-positive cocci, endospore and forming rods. There was no difference in the total bacterial population with plant age , but the types of colony growth were reversed between the rhizosphere and non-rhizosphere soil in 5 week (seedling stage) and 20 weeks (maturity stage).The genus of Burkholderia prevail in the rhizosphere of the wheat particularly in the early stages of plant growth (seedling stage). The changes in the trend of the calculated ratio of gram-negative bacteria in the rhizosphere to that of the non-rhizosphere soil cannot be generalized to all species. Results obtained with Burkholderia population in this experiment showed different picture.