Journal of Stress Physiology &
Biochemistry, Vol. 9 No. 1
2013, pp. 54-65 ISSN 1997-0838
Original Text Copyright (cc) 2013 by Surekha Rao, Mishra, Gupta and
Rathore
ORIGINAL
ARTICLE
Data source : Google Scholar
QueryDate : 2016-12-24
Cites : 4
Physiological Response to
Salinity and Alkalinity of Rice Genotypes of Varying Salt Tolerance
Grown in Field Lysimeters
P. Surekha Rao1, B. Mishra1,
S.R. Gupta2, A. Rathore3 1 Central Soil Salinity Research Institute,
Karnal-132 001, Haryana, India. 2 Kurukshetra University, Kurukshetra-136119, Haryana, India 3 IISS, Nabibagh, Bhopal-462.38, Madhya Pradesh, India
Phone 91-755-2625547; 91-9329524374
*E-Mail: psurekha_rao@rediffmail.com Received September 19, 2012
Soil salinity and alkalinity
seriously threaten rice production in south Asia. Improving screening
methodologies to identify sources of tolerance for improved breeding
for salt tolerant rice is of continuing importance. Rice genotypes of
varying salt tolerance, such as tolerant (T), semi-tolerant (ST), and
sensitive (S), were grown in field lysimeters in saline soil of ECe 4
and 8 mS cm-1 and alkali soil of pH 9.5 and 9.8 in North
India and analyzed for chlorophyll (Chl), sugar, starch and proline in
leaves. Chlorophyll a and b decreased due to salinity in all the
tolerance groups. However, Chl a was not much affected but chl b
increased with alkalinity. Under high stress both at ECe 8 and pH 9.8
Chl a and b were more in tolerant than in sensitive genotypes. The
ratio of Chl a/b was similar in T, ST and S genotypes under salinity
stress. Sugar accumulation was higher in T compared to S under normal
conditions but under salinity or alkalinity stress the differences were
not significant. Leaf starch was highest in T, intermediate in ST and
lowest in S genotypes in normal as well as under salinity and
alkalinity stress. There was decrease in starch with salinity and
alkalinity stress only in T group but not in ST and S group. Proline
increased significantly in all the tolerance groups even at low
salinity of ECe 4 mS cm -1 or pH 9.5. The salt tolerant
genotypes of rice maintained higher levels of Chl a and b, starch and
proline under high salinity and alkalinity stress and are the robust
criteria for tolerating high salinity and alkalinity.
Key
words: Chlorophyll, Osmolytes, Proline, Salt
stress, Starch, Sugar
