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Rhizosphere |
Rhizosphere
Rhizosphere is the region outside the root where microbial activity is usually high.
The rhizosphere is the actual root surface. Microbial
numbers are always higher in the rhizosphere and rhizoplane than in region of
soil devoid of roots. Here moisture is less variable, nutrient concentration is
high and microbial communities are the most diverse and abundant. These roots
excrete significant amount of sugars, amino acids and hormones, vitamins.
Bacteria and fungi often form microcolonies on the root
surface.
Rhizosphere
Effect
Within the rhizosphere plant roots have a direct
influence on the composition and density of the soil microbial communities.
Rhizosphere
Microflora
The interactions of plant roots and rhizosphere
microorganisms are based largely on interactive modifications of soil
environment methods.
There is a higher proportion of Gram negative rod shaped bacteria
and a lower proportion of Gram positive rods, cocci and pleomorphic forms in
the rhizosphere than in root free soil.
There is also motile, rapidly growing bacteria, Pseudomonus.
The microaerophilic Azospirillum
and the aerobic Azotobacter paspali are nitrogen fixing soil
bacteria associated with the tropical grasses of Digitaria, Panicum and
paspalum genera.
These bacteria use root exudates as the energy source to
support nitrogen fixation.
The rhizosphere of eel grass and turtle grass in the
site of high nitrogen fixation activity by Desulfovibrio,
Clostridium and other anaerobes.
Rhizosphere
Written By
Sadia Akhtar
Student of Department of Microbiology
Jagannath University.
Email- sadiabd810@yahoo.com
Student of Department of Microbiology
Jagannath University.
Email- sadiabd810@yahoo.com
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