Journal of Stress Physiology & Biochemistry, Vol. 7, No. 2,
2011, pp. 117- 138. ISSN 1997-0838
Original Text Copyright (cc) 2011 by Farouk
ORIGINAL
ARTICLE
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QueryDate : 2016-12-24
Cites : 16
Osmotic adjustment in wheat flag leaf in relation to
flag leaf area and grain yield per plant
Farouk S. Agric. Botany
Department, Faulty of Agriculture, Mansoura University, Mansoura, Egypt Email:gadalla@mans.edu.eg
Received April 12, 2011
Background Salinity stress causes ion toxicity and osmotic imbalances,
leading to oxidative stress in plants. Antioxidants are considered
ameliorators of saline stress and could develop salinity tolerance in
crop plants. To ascertain the role of antioxidants in inducing osmotic
adjustment in salt stressed wheat flag leaf in terms of compatible
solutes accumulation, water relations parameters and osmotic
adjustment as well as flag leaf area and grain yield per plant,
in addition, flag leaf anatomy were examined.
Results Salt stress up to 11.5 dSm-1 causes a significant
reduction in water potential, osmotic potential, as well as
relative water content, and water content. On the other hand, turgor
potential and osmotic adjustment were significantly increased due to
inducing increasing the higher accumulation of compatible osmolytes
which leads to decreasing flag leaf area and grain yield per plant.
Application of both antioxidants, in particular, ascorbic acid
increased significantly flag leaf area, and grain yield per plant due
to osmotic adjustment and maintaining leaf turgor potential as a
consequence of increasing leaf water potential, water content and
relative water content as compared to control plants. On the
other hand, application of both antioxidants under all salinity levels,
nullify the harmful effects of salinity on flag leaf area and grain
yield per plant due to increasing osmolyte accumulation,
maintaining turgor potential and osmotic adjustment.
Anatomically, increasing salinity levels decreased thickness of leaf
blade at midrib region, thickness of mesophyll tissue, tangential
dimension of midrib vascular bundle, thickness of upper and
lowerepidermis, thickness of big motor cell, and tangential dimension
of big xylem vessel. Treatment with either ascorbic acid or tocopherol
at 100 mg/L and their interactions with salinity increased all the
above mentioned parameters in both nonsalinized and salinized plants.
Ascorbic acid is the most effective in this concern.
Conclusion In conclusion, wheat plants responded to an increased ion influx
in their cells by increasing the osmolytes synthesis and accumulation
under salt stress, which further increased with antioxidants treatment
and helped in maintaining the osmotic balance.
