Abstract:
In order to evaluate salt (NaCl) tolerance in alfa
lfa (
Medicago sativa
L.) half-sib
families, a factorial experiment on the basis of co
mpletely randomized design, with 20-25
individuals in pot (replicates) was carried out und
er field conditions at the Research
Station of University of Tabriz. Electrophoretic an
alyses were performed by using 7.5%
slab polyacrylamide gels. Two antioxidant enzymes i
ncluding superoxide dismutase
(SOD) and peroxidase (POX) and one common isozymic
system namely esterase (EST)
were stained and for each isozymic band the “densit
y × area” scores onto gels were
evaluated by MCID software as enzymatic activity. P
lant materials consisted of 12 half-
sib families that were obtained from a “polycross n
ursery progeny test” in the same
station, a few years ago. The applied salt stress (
9±0.2 ds m
-1
) reduced plant height, dry
weight, leaf weight and stem weight about 31.7, 37.
5, 33.7 and 34.7 percent, respectively.
Significant correlations were observed between plan
t height and some antioxidant
isozyme activities. Salt stress increased activitie
s of some SOD and POX isozymes but it
was ineffective on the activity of EST. Among the f
amilies, Ranger cultivar and Zaghl-
aghaj and Taze-kand landraces which displayed maxim
um height and other
characteristics exhibited the highest increments in
respect of isozyme activities, indicating
that antioxidant analysis by gel electrophoresis co
uld be a useful tool for salt stress
tolerance studies.
Keywords:
Alfalfa half-sib families, Isozyme activities, Sal
t stress.
