Molecular Identification of Biodiversity of Fusarium species Isolated from Wilted Oil Palm and Date Palm in Nigeria.

Biodiversity of sixteen Fusarium isolates, isolated from the roots of oil palm and date palm in Nigeria was studied. Ten Fusarium isolates out of the sixteen were obtained from the oil palm while six isolates were from date palm. Random Amplified Polymorphic DNA (RAPD) was used to detect the phylogenetic similarity between them. The unweighted Pair Group Method with Arithmetic average (UPGMA) dendrogram clearly separated these sixteen Fusarium isolates into five groups (clusters). The first at SC values of 100 grouped six Fusarium isolates (5, 2, 13, 9, 8 and 14,) of both oil and date palms. They belonged to F. oxysporum and F. chlamydosporum. The second at SC values of 100 had one Fusarium isolate (16) of date palm. It belonged to F. solani. The third at DC values of 71-100 grouped six isolates (6, 4, 3, 7, 11 and 10) of oil and date palms. They all belonged to F. solani. The fourth at DC value of 76 had one Fusarium isolate (1) of oil palm, it belonged to F. nelsonii. The fifth at SC value of 100 grouped two Fusarium isolates (15,12) of date palm. They belonged to F. nelsonii and chlamydosporum. The sequence alignment technique showed there were similarities between these sixteen Fusarium isolates. The analysis of RAPD showed that the sixteen Fusarium isolates were five groups while sequence alignment technique grouped them into five Fusarium isolates. The slight difference in similarity may be attributed to ecological origin and zone of the Fusarium isolates.

Effect of myoinositol on sporangiospore-yeast transformation of Mucor circinelloides Tieghem cultivated in synthetic broth.

Mucor species exhibit fungal dimorphism in controlled environments. In this work, we examined the effect of myoinositol supplementation on the growth and morphology of Mucor circinelloides. Using sporangiospores as inoculums, diverse morphologies were induced in synthetic broth incubated at pH 4.5, temp. 20 degrees C, ambient. The morphologies included thallic suptypes (holoblastic-, holothallic-, enterothallic conidia as well as vesicular conidial headgroups), which were determinate in growth, and proliferating yeast forms. Analysis of variance, p<0.05, showed that time had significant impact on growth. A separation of means, l.s.d. 14.34, p<0.05, indicated that myoinositol supplementation at 500 microM supported the least growth, but 2.0-3.0 mM levels had the higher values, and this was followed by the control, 300 microM, 1.0, 2.0, 5.0 mM supplementations. Although the predominant morphology, that is, terminal budding yeast cells was not quantitated, observation showed that it was more preponderant, had optimal size and cell shape became more regular at 2.0 mM myoinositol supplementation.