INVESTIGADORES
MAESTRI Damian Modesto
congresos y reuniones científicas
Título:
Effects of different water deprivation levels on arbuscular mycorrhizae fungi associated to olive trees
Autor/es:
PIERLUIGI PIERANTOZZI; ALEJANDRA BECERRA; MARIELA TORRES; DAMIÁN MAESTRI; EDUARDO TRENTACOSTE; CARLOS PUERTAS; EDUARDO NOUHRA
Lugar:
San Juan
Reunión:
Simposio; VIIth International Symposium on Olive Growing; 2012
Resumen:
Olive trees have great adaptability
to adverse soil conditions and are typically grown on marginal soils with low
fertility. Water deficit and osmotic imbalance are the most common stresses
affecting crops in arid and semi-arid regions. Tolerance to osmotic stress in
plants is a complex phenomenon and involves many changes at the biochemical and
physiological levels. However, the mechanisms behind the modulation of tissue
water conductivity and osmotic adjustment appear to be affected by mycorrhizae
colonization. The aim of this
study was to evaluate the effect of water availability on mycorrhizal
colonization of olive trees (cv. Arbequina) grown at two different
agro-climatic environments. The experimental design included two water deficit treatments, one at
50% of the estimated crop evapotranspiration (Mendoza province) and another under
natural rainfall (Cordoba province), and a treatment irrigated at 100% of the estimated
crop evapotranspiration at both cultivation sites. The root-associated soil
samples from each individual plant (n=10) were randomly collected at 10 to 20 cm depth. Each sample consisted of
five bulked sub-samples (200 cm3 soil cores). The arbuscular mycorrhizal colonization rate was
higher in treatments with lesser water availability; the average increments
were found to be 42% and 75% for Mendoza and Cordoba, respectively. The same
pattern was found in the number of soil mycorrhizal spores; the average
increments for Mendoza and Córdoba were 42% and 121%, respectively. Irrigation
treatments did not display any change on the dark septate endophytes rate, but significant
differences were observed due to the growing environment (p ≤ 0.01). These
results suggest that water uptake by mycorrhizae hyphae and/or increased water uptake related to
mycorrhizae changes in root morphology or root fineness could conceivably allow
mycorrhizal plants in drying soil to effectively providing roots access to more
of the soil water reservoir.