Abstract

The objectives of this study were to determine the effects of micronutrient deficiency on root colonization by arbuscular mycorrhizal fungi (AMF), and to assess the role of AMF on growth of sorghum and tomato plants in perlite bed culture. In a pot culture experiment with sterile perlite, sorghum (Sorghum bicolor L.) and tomato (Lycopersicon esculentum Mill.) plants were inoculated with either Glomus etunicatum or Glomus intraradices, or left un-inoculated as control, and  three levels of micronutrients (zero, half and full strength) in Rorison’s nutrient solution were applied to the pots during vegetative growth period. In tomato plants, the mycorrhizal symbiosis was not observed. In addition, fungi treatments had no significant effect on dry weights of root and shoot of tomato plants. In sorghum plants, average root colonization for G. etunicatum and G. intraradices were 43 and 37%, respectively. Nevertheless, there were no significant differences in root colonization between G. etunicatum and G. intraradices fungi treatments with supplied levels of nutrient solution. In addition, three levels of supplied nutrient solution did not have significant effect on root colonization percent. Moreover, mycorrhizal symbiosis decreased dry weights of root and shoot of sorghum plants. It seems that, these results related to phosphorus concentration in Rorison's nutrient solution.

Key words: Mycorrhizal fungi, micronutrients, sorghum, tomato, perlite, colonization, dry weight.

Abbreviation

Abbreviations: AMF, Arbuscular mycorrhizal fungi; VAM, vasicular-arbuscular mycorrhizal.