Abstract:
Sunflower plants became mycorrhizal as early as 2 leaves stage in P-deficient soil. The controls were grown in formalin treated, sterilized soil. Endogone free filtrate including only microorganisms from the same soil was added to the controls. There was a correlation between the extent of infections and number of leaves. The VA endophyte responsible for the mycorrhizal infections included white reticulate, honey coloured sessile, red brown laminate and yellow vacuolate type of spores. Mycorrhizal plants at the time of harvest were taller, stouter with more numerous and larger leaves and bore bigger discs producing viable seeds. The controls showed symptoms of P-deficiency and produced smaller discs with about 50-60% non-viable seeds. The greater growth of mycorrhizal plants is attributed to greater uptake of P from the soil. mycorrhizal plants removed more P from the rhizosphere. The external hyphae of the VA endophyte provide the host plant with an additional well-distributed absorbing surface which absorbs phosphate from outside the depletion zone around the root.
Page(s):
189-196
DOI:
DOI not available
Published:
Journal: Biologia, Volume: 23, Issue: 2, Year: 1977