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International Conference on

Recent Trends in Environmental Sustainability

ESCON22/SAgri/43

Changes in page tangelo (Citrus reticulate) responses to drought stress and
superabsorbent polymer aquasorb application
Zeinab Rafie Rad1, Ahmad Golchin1, Yahya Tajvar2, Ashir Masroor3*, Javad Fattahi
Moghadam2, Taqi Raza4
1Department of Soil Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.

2Horticultural Science Research Institute, Citrus and Subtropical Fruits Research Center,
Agricultural Research Education and Extension Organization (AREEO), Ramsar, Iran.
3University of Agriculture Faisalabad, Sub-Campus Burewala, Pakistan
4Department of Biosystems Engineering & Soil Science, University of Tennessee, Knoxville
USA
Correspondence: masroorakb@gmail.com

Abstract
Identification of the techniques that increase the drought stress tolerance such as soil water-
retaining polymers and their application in citrus can help to improve the growth, production,
and fruit quality. Thus, this study was carried out to investigate the effects of superabsorbent
polymer aquasorb (SAPA) on physiological and biochemical properties of page tangelo (Citrus
reticulate) under 100, 75, and 50% field capacities (FC). Three different levels of
superabsorbent polymers aquasorb (SAPA) were mixed with the soil, including 0 (SAPA1),
0.25 (SAPA2), and 0.5 (SAPA3) weight percentage of the soil. Results indicated that SAPA3
significantly increased in net photosynthetic rate, stomatal conductance, photosynthetic
pigments, leaf relative water content, and leaf water potential under drought stress conditions.
Furthermore, it was recorded that proline contents also remarkably increased under severe
drought stress conditions. Similarly, it was observed that the accumulation of such metabolites
was rather higher in SAPA1 as compared to other levels of SAPA. However, the enzymic
activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were reduced
with SAPA3 application under severe drought stress, but SAPA led to a decrease in
accumulation of superoxide radical (O2−), hydroxyl radicals (OH−) and hydrogen peroxide
(H2O2). SAPA3 application also decreased total soluble solids (TSS) of fruit under water stress
but increased vitamin C contents and fruit yield under drought stress treatments. An increase
in yield and water use efficiency was also observed in drought-stressed plants. Hence, the
research conducted indicated that the application of SAPA can mitigate the negative effects of
water stress on plant growth and fruit yield through protecting photosynthetic systems,
improving leaf water status, and water use efficiency.
Keywords: Citrus reticulate; Drought stress; Stomatal conductance; Superabsorbent polymer;
Peroxidase; Vitamin C

Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus

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