Arbuscular mycorrhizas and Zn fertilization modify growth and physiological behavior of apricot (Prunus armeniaca L.)

Abstract

This paper describes an experiment on the influence of indigenous arbuscular mycorrhizal fungi (AMF) on growth, biochemical characteristics, mineral nutrient content and its uptake by leaves of apricot seedlings cv. New Castle. Four AM fungal species namely, Glomus fasciculatum (Thaxter) Gerdemann & Trappe, G. mosseae (Nicol. & Gerd.) Gerdemann & Trappe, G. macrocarpum (Tul. & Tul.) and Sclerocystis dussii (Almeida & Schenck) were first isolated, identified and characterized from rhizosphere soils of the local apricot orchards being grown in mid-hill agroclimatic zone conditions of the State of Himachal Pradesh. AM fungal species isolated, were subsequently multiplied and inoculated for the evaluation of their comparative performance in apricot seedlings, at nursery stage singly and in combination with varied Zn fertilization levels viz., 0, 2.5, 5.0, 10.0mgkg−1 to improve plant productivity parameters for sustainable nursery management. The research studies showed that the soil inoculation of G. fasciculatum (Thaxter) resulted in maximum sporulation in rhizosphere, root colonization, improved vegetative growth measurements, biochemical attributes, leaf nutrient content and subsequently its uptake in the seedlings compared to uninoculated control. The results also inferred that the inoculation of G. fasciculatum (Thaxter) at 5.0mgZnkg−1 was the most effective to maximize spore count, root colonization, plant height, stem diameter, shoot dry weight, root dry weight, leaf area, total chlorophylls and total phenolic content in leaves with corresponding values of 218, 6, 196.4, 150.0, 112.4, 170.2, 47.9, 167.6%, respectively. Higher levels of phosphorous (P: 57.9%), iron (Fe: 30.4%), copper (Cu: 75.4%), zinc (Zn: 82.4%), manganese (Mn: 87.5%) in leaf with its corresponding leaf uptake of 180.9, 203.9, 71.3, 85.8 and 291.6% were also recorded with the inoculation of G. fasciculatum (Thaxter) at 5.0mgZnkg−1 soil in the apricot seedlings.