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EFFECT OF SALINITY
AND SILICON APPLICATION ON OXIDATIVE DAMAGE
OF SORGHUM [SORGHUM
BICOLOR (L.) MOENCH.]
MOHAMMAD KAFI*,
JAFAR NABATI, ALI MASOUMI AND MOHAMMAD ZARE MEHRGERDI
Abstract:
Application of silicon (Si) to soil is considered as an alternative
approach to alleviate salinity stress in crop plants. Therefore, a field
experiment was conducted to investigate the effects of Si application
[control (without Si), 1.44 and 1.92 g.kg-1soil on membrane
stability index (MSI), relative water content (RWC), leaf proline,
soluble sugars, antioxidant activity, total phenols and dry matter
accumulation of two sorghum (Sorghum bicolor)
cultivars under three levels of salinity of irrigation water (5.2,
10.5 and 23.1 dS m-1). The results
showed that leaf proline content, activities of ascorbate peroxidase
(APX) and glutathione reductase (GR), Na+ concentration
significantly increased only at high level of salinity, while, RWC and
dry matter accumulation were significantly decreased at all salinity
levels. Soil application of 1.44 g.kg-1 Si caused an increase
in the activities of APX, catalase (CAT), superoxide dismutase (SOD),
peroxidase (PRO), glutathione reductase (GR), total antioxidant and
total phenol contents and 1.92 g.kg-1soil Si caused an
increase in membrane stability index, soluble sugar and total phenol
contents, CAT, SOD and total antioxidant activity. Soluble sugars, total
phenols, SOD and total antioxidant activity and dry matter accumulation
in cv. Omidbakhsh were higher than those in cv. Sepideh. In conclusion,
alleviation of salinity stress by exogenous application of Si was found
to be associated partly with enhanced antioxidant activity.
Faculty of
Agriculture, Ferdowsi University of Mashhad, Iran
*Corresponding
author’s e-mail:
mkafi36@yahoo.com
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