Arbuscular mycorrhiza and their effect on the vegetative development of lemon (Citrus limon L.) rootstocks

Abstract

Citrus fruits are the most economically important fruit crop in the world. In Nicaragua, citrus production generates USD 24.5 million annually. The diseases that can be prevented by inoculating mycorrhizae in rootstocks are root rot caused by Phytophthora sp. and the dry disease of citrus by Fusarium sp. The introduction of disease resistant patterns is a necessity in today's citrus industry. In the last decades, arbuscular mycorrhizal fungi have been used for the beneficial effect they produce on their hosts. The objective of this study was to evaluate the effect of arbuscular mycorrhiza on the vegetative development of Citrange Troyer and Citrange Carrizo rootstock. The inoculated mycorrhizal fungi were isolated from the Félix, Marino and San José citrus farms. The genus identified with the highest percentage was Glomus sp, with 97 % to 99 %, while the genera Scutellospora sp., Gigaspora sp., Septoglomus sp. and Acaulospora sp., represented 1 % respectively. The percentage of root colonization with the Glomus sp. genus was 93 % for the Troyer graft holder and in Carrizo it was 83 % to 100%. The effect of Glomus sp. was evaluated by measuring the variables plant height (cm), number of leaves, stem diameter (mm), root length (cm) and biomass (g). The results of the analysis of variance and separation of means of Tukey (α = 0.05), show significant differences for the Troyer rootstock in the variables stem diameter and root length with the isolate from the San José farm, in the case of the root Carrizo graft the number of leaves, stem diameter and root length showed the highest values with the isolate from the Felix farm.