Vesicular arbuscular mycorrhizas (VAM) are extremely successful fungi that form mutualistic symbioses with about two thirds of all plant species (Smith & Read 1997). VAM fungi are of great ecological importance since arbuscular mycorrhizae are the most widespread plant symbiosis that often improves plant productivity (Fedderman et al., 2010). The main advantage of mycorrhizae to the host plants are increased efficiency of mycorrhizal roots versus non mycorrhizal roots caused by the active uptake and transport of nutrients especially immobile minerals like P, Zn and Cu (Phiri et al., 2003; Jamal et al., 2002). This work is achieved by the interconnected networks of external hyphae which act as an additional catchment and absorbing surface in the soil (Sharma, 2004).
Gallaud (1905) described two morpho types of the VAM fungi as the Arum type and Paris type. The Arum-type form extensive intercellular hyphae in air spaces between cortical cells and invaginate the plasma membrane of the cells as short side branches to form arbuscules while the Paris type, the colonization spreads from cell to cell in the cortex thus develop intracellular hyphal coils that frequently have intercalary arbuscules. Most species of plants including grasses, herbs, and tropical trees form Vesicular-arbuscular mycorrhiza (Gerdemann, 1965, 1968). While the VAM fungi are benefited with carbon substrates from plants and shelter in return to the host plant they provide enormous benefits to their host. Among them include improving plant nutrition, (Van der Heijden et al., 1998), help to control pests and fungal pathogens (Pozo et al., 1996, 2010), increase uptake and transport of soil nutrients (Cox et al., 1975; Abbot & Robson, 1984; Newman & Reddel, 1987) enhancing water movement, Auge, 2001), promote positive diversity (Laura et al., 2010) as well as reducing pathogenic infections to their host (Dehne, 1982; Fitter, 1986).
In developed countries VAM fungi have been substantially studied (Cox et al., 1975; Abbot & Robson, 1984; Newman & Reddel, 1987, Laura et al., 2010) due to its importance in forest conservation. Although SNP is hot spot of biodiversity, the studies on the fungi and specifically the VAM fungi has been completely neglected, yet successful conservation efforts in any ecosystems may require understanding of fungi communities in terms of ecology and distribution. Apart from Tibuhwa et al. (2011) and Tibuhwa (2011, 2012) who mainly examined the macro-fungi, no any studied on fungi that have been done in the SNP. This study therefore, examined the VAM fungi and establishes the effect of the land types to the VAM morphotypes, diversity and abundance in the SNP.
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(Author: Salehe Twahir, Donatha Damian Tibuhwa