Morphophysiological studies for salinity tolerance in oat (Avena sativa L.)
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Date
2013
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
The present investigation was conducted on two genotypes of oat (Avena sativa L) using various
morpho-physiological traits for their salinity tolerance.The seed of two genotypes of oat namely (NGB 6370 and
NGB 4462) were procured from Indian Grassland Fodder Research Institute, (IGFRI), Jhansi and the experiment
was conducted in the micro salinity plots in the Department of Soil Sciences, CCS Haryana Agriculture
University, Hisar.
The crop was raised in micro plots of 2m×2m in size in a single row each 25 cm apart with three
replication .Before sowing the plots were irrigated with desired levels of salinity i.e. control, 4 dSm
-1
, 8 dSm
-1
,
12dSm
-1
. The control plots were irrigated with canal water.
The observations were recorded at vegetative and flowering stages. The present decline in plant height
(29.4 to 54.2%), leaf area (55.3 to 59.2%) and dry weight plant
-1
(46.9 to 83.3%), no. of tillers plant
-1
(13.3 to
33.3%), relative water content (4.62% to 12.8%), water potential (-0.35 MPa to -0.50 MPa) and osmotic potential
(-1.86 MPa to -2.1 MPa) were recorded when salinity was increased from 4 to 12 d Sm
-1
as compared to control.
Proline content (24.1 to 74.1) and total soluble carbohydrates contents (21.3 to 63.6) were increased as we move
from increasing the salinity. However quantum yields (0.50 to 0.36) and chlorophyll stability index (92.03 to
73.87) of oat genotypes were also reduced significantly. However a reverse trend was observed for relative stress
injury (RSI%) (5.12 to 15.6%) and malondialdehyde content (MDA) (33.2 to 67.9%). The Na
+
, Cl
-, SO
4
2 –
content
were increase but K
+
content was decreased. With the increase in salinity levels activated antioxidant enzyme
system especially catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductase (GR) and
glutathione transferase (GTase) was observed however, no such activation was observed in case of superoxide
dismutase (SOD).Genotypes, NGB 6370 showed better tolerance against different levels of saline irrigation than
the genotype namely NGB 4462. Its better performance was based on physiological traits like plant water status in
terms of more ‘ –ve ’ values of (ψ
w
) and (ψ
s
), higher values of RWC (%), low values of RSI (%), F
V
/F
m but low
values of RSI(%) and MDA content. The Na
+
/Ka
+
ratio and Cl
content were also higher in sensitive genotype
(NGB 4462) than the tolerant genotype (NGB 6370). The specific activity of antioxidative enzymes i.e (CAT,
POX, APX, GRase, GTase) were also higher in NGB 6370 than NGB 4462. These physiological traits contributed
towards the better plant growth in NGB 6370 genotype and further were correlated to their higher yield potential.
Molecular marker of proteins of bands 14.4, 20.1, 30.0, 45.0, 97.0 KDa were obtained. New stress proteins of MW
91, 63, 43, 23, 22, 21 KDa were present irrespective of the treatments in NGB 6370 as compared to genotype NGB
4462, which were responsible for salinity tolerance in NGB 6370. Rest of the new proteins synthesized of different
MW were common in both the genotypes. The other new stress proteins of MW 63, 57-56, 45, 39, 38, 33, 28 and
22 KDa were appeared in Fig. A.
Grain yield decreased from (20.8% to 5.2%) and seed weight (39.9% to 65.8%) as we increased the
salinity from 4 dS m
-1
to 12 dS m
-1
as compared to control. Similar trend was observed in flowering stage.
Description
Keywords
Antioxidative activity, Chlorophyll fluorescence, Mmembrane injury, Ooat, Mminerals, Water relations