01418naa a2200265 a 450000100080000000500110000800800410001910000210006024500540008126000090013552007570014465000180090165000160091965000150093565000140095065000110096465300150097565300170099065300270100765300260103465300150106065300150107565300120109077300500110220144152015-04-27       1968    bl ---       0--  u    #d1 aGERDEMANN, J. W.  aVesicular-arbuscular mycorrhiza and plant growth.  c1968  aA region of intense microbial activity exists in the soil surrounding plant roots. Large numbers of saprophytic soil-inhabiting microorganisms in the rhizosphere interact with the plant, and more specialized parasitic organisms infect living roots and utilize them as a source of food. Host tissue becomes disorganized in the process, and plant disease results. In more highly specialized microbial root associations the root becomes infected, and an intimate balanced relationship is established. The morphology of the host tissue may be modified; however, the microorganism obtains food from the host without destroying or adversely affecting the functioning of root tissue, and under some conditions the infection is actually beneficial to the host.  aColonização  aCrescimento  aInfecção  aMicorriza  aPlanta  aMicorrhiza  aMICORRIZA/VA  aMicrobiologia de solos  aMicrobiology of soils  aMORFOLOGIA  aOCORRENCIA  aREVISAO  tAnn. Rev. Phytopathol.gv.6, p.397-418, 1968.