Studies on the Rhizosphere Mycoflora of Celosia Argentea (L) and Hibiscus Esculentus
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University of Lagos
Rhizosphere studies of two local green vegetables, celosia aregentea Linn and Hibiscus esculentus Linn (new name Abelmoschus esculentus) were studies from vegetative stage to senescence. The viable seeds beds made from sandy loam soil. Samples were collected at two-week intervals at 9.00 hrs in the morning. Morphologically, A. esculentus (okra) had 3 leaves with more dense rooting system at 2 weeks than C. argentea (soko) with 6 leaves. Both plants appeared to reach maturity at the 14th week after planting. Both plants encouraged the growth of fungi and bacteria in the vicinity of their roots due to their secretions inti the soil. In the 14 th and 16th weeks of growth however, when the plants fruits were fully developed, fungal and bacteria populations were repressed. Twenty species of fungi belonging to 9 genera were isolated from non-rhizosphere and rhizoplane of okra while 12 and 9 were obtained from the rhizosphere and rhizoplane of soko. Aspergillus was the dorminant genus isolated. Other genra include penicillium, Trichoderma, Fusarium, Curvularia, Rhizoctonia, Gliocladium, Myrothecium, Scolecobasidium, Botryodiplodia and sterilla mycelia. Biochemical studies revealed that no sugars were detected chromatographically from any of the root exudates. Okra exudate was however found tocontain alanine and glycine while ‘soko’ exudate contained aspartic acid, glutamine and an unidentified amino acid. Most of the isolated fungi were found to grow together in petri dishes without any inhibitions. Trichoderma harzianum Rifai however was found to be antagonistic to Rhizoctonia spp. Studies on this activities of some fungicides showed that thiram (arasan) which was most effective in reducing microbial population in the soil persisted in the garden soil for 35 days after application. A few of the isolated fungi were found in nutritional experiments to utilize carboxy methyl cellulose (CMC) as the sole carbon source
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Hibiscus Esculentus , Rhizosphere Mycoflora , Local Vegetables , Fungi
Igbosuah, E. O. (1983). Studies on the Rhizosphere Mycoflora of Celosia Argentea (L) and Hibiscus Esculentus (L). A Thesis Submitted for the Degree of Doctor of Philosophy (Botany) of the University of Lagos.