| Abstract | dc.description.abstract | Aloe barbadensis Miller, known as Aloe Vera, requires limited irrigation depending on the capacity of the
soil to retain humidity, since it is a CAM species and thus naturally adapted to conditions of dryness and
high temperatures. Therefore, we postulated that plants of Aloe Vera plants under conditions of water
deficit should improve their water use efficiency (WUE) by performing osmotic adjustment (OA) with a
temporal correlation betweenWUEand OA. The objective of the investigation was to determine the effect
of water restriction on the WUE and OA of A. barbadensis under different water treatments. 18-month
old Aloe Vera plants were cultivated in pots with a soil substrate that was a mixture of equal parts of
sand and organic matter with 18% of FC and 9% of permanent wilting point. To determine the effects of
the soil humidity on plant WUE and OA, four treatments were arranged in a complete random design
with four repetitions; these were 100%, 75%, 50% and 25% of FC, which correspond to an evatranspiration
of 11.4, 9.6, 4.0 and 1.7 L per plant, respectively. The water treatments were maintained by frequent
irrigation. The following variables were determined: dry matter, leaf water potential, relative water
content (RWC), amount of gel produced, sap flow, proline content, soluble and total sugars and oligo and
polyfructans. Aloe Vera increased WUE with increasing water deficit; the sap flow rate decreased with
water restrictions, and the plants performed osmotic adjustment by increasing the synthesis of proline,
soluble and total sugars as well as the amounts of oligo and polyfructans, mainly polymers of -(2→6)
kestotriose, changing from the inulin type to the neofructan type. The plants most and less irrigated (100%
and 25% of FC) were the groups with lowest WUE. The plants irrigated with 75% of FC presented the best
WUE in terms of dry mass and amount of gel produced by a litre of supplied water. | es_CL |
