51 females subsequently resulting to lower total nematode densities in the plants.
Other examples of production of toxic metabolites by endophytic fungi have also been reported by Ma et al. 2004 that production of rhizoctonic acid and
momomethylsulochrin, ergosterol and 3 β, 5α, 6β-trihydroxyergosta-7.22-dien by
an endophytic isolate of Rhizoctonia sp. An in vitro experiment was conducted earlier in this research to show the mechanism of antibiosis by the endophytic
fungi against root-knot nematodes as indicated in Table 12.
4.2.4 Effect of Endophytic Fungi on Plant Growth
The results from this study demonstrated that root endophytic fungi from tomato plants effectively promote
d
growth of the host plant. All the endophytic fungi treatments showed high significant effect in increasing plant growth
parameters. Endophytic fungi that significantly increased plant growth included; Nigrospora
sp, isolate XP9, Fusarium oxysporum, Fusarium chlamydosporum, Chrysosporium
sp, Trichoderma hamatum, Trichoderma pseudokoningii, Sterile black 1, Torula sp, Sterile black 2, in relation to this a lot of research has been
conducted on the use of endophytic fungi to stimulate plant growth, for example Fusarium
sp and Trichoderma sp have been found to have effect on plant growth promotion in tomato plants Amin et al. 1997. Although the mechanism
by which the endophytic fungi promote plant growth
was not investigated in this study, the results gave some insight about the endophytic fungi and the host relationship.
The mechanisms by which endophytic fungi stimulate the host growth could be attributed to the production of hormones and phytohormone because
phytohormones are capable of stimulating host plant growth. Many strains from genus of Fusarium and other endopyhtic fungi could produce phytohormone such
as gibberellins, and auxins IAA Chen et al. 1997; Nassar et al. 2005. Production of indole-3-acetic acid IAA and indole-3-acetonitrile has been
demonstrated in vitro in a number of fungal species including Aurebasidium pullulans
De Bary Arnaud, Epiccoccum purpurascens Pugh 1972. Strains of endophytes tested by Bergamin-Strotz 1988 have the ability to produce IAA and
other auxins in vitro, in some cases, the production of cytokinins has also been assessed. Investigations by Bergamin-Strotz 1988 also showed that one
52 endophytic strain Hypoxylon serpens isolated from tobacco stimulated the
flowering process of the host. In this research high plant heights, stem diameters, plant fresh weight,
plant dry weight, root length, number of fruit that developed in the tomato plants was generally increased in endophyte treated plants. All the endophytic fungi
isolates were found to be effective in stimulating growth parameters and their effect in growth stimulation differed significantly at p0.05 according to Duncan
Multiple Range Test.
4.2.5 Antibiosis
