THE INFLUENCE OF ARBUSCULAR MYCORRHIZAL COLONIZATION ON THE GROWTH PARAMETERS OF CAPE GOOSEBERRY (Physalisperuviana L.) PLANTS GROWN IN A SALINE SOIL
With the objective of determining whether arbuscular mycorrhizal (AM) colonization would alleviate salt stress on the growth of cape gooseberry plants, a saline soil (ECs of 5.65 dS m-1, available phosphorous of 48.1 mg kg-1) was inoculated with AM fungi (Mycoral®) (+AM) and compared to a non-inoculated saline soil (-AM). The open-field experiment was conducted over the course of 131 days on the Marengo farm of the Universidad Nacional de Colombia (near Bogotá, 4°42' N, 74°12' W, 2543 m a.s.l., 14°C mean temperature, and 800 mm a-1 precipitation) where the plants were irrigated with water (ECs of 1.65 dS m-1) from the salt-contaminated Bogota river. Mycorrhizal dependence, AM colonization, relative field mycorrhizal dependency (RFMD100), dry matter (DM) accumulation and growth parameters (unit leaf rate [ULR], leaf area ratio [LAR] and specific leaf area [SLA]) were determined. The percentage of AM-colonization was 29.7% in +AM plants, but only 12.5% in -AM plants. The RFMD100 index peaked at day 61 (42.5%) and decreased to 7.8% by day 89. Inoculation with AM fungi increased plant dry matter accumulation by 7%, especially stem DM, compared to -AM plants. Generally, growth rates were higher in the +AM plants; ULR increased more in the second half of the experiment in inoculated plants compared to non-inoculated. The mycorrhizal infection enhanced leaf area growth, which resulted in increased LAR and SLA, especially during the initial phases of the experiment.