Abstract:
Sorghum [
Sorghum bicolor
(L.) Moench] is moderately tolerant to salinity and it is
important as a candidate crop for both fodder and grain in salt
-
affected areas. This pot
experiment was conducted at Research Greenhouse of College of Agriculture, Shiraz
University, Iran, to evaluate the relative effectiveness of biochemical traits and stress
tolerance indices contributing to genotypic differences in
salinity tolerance in 30 lines and
14 cultivars of sorghum. In addition, a new indicator, Storage Factor Index (SFI), was
defined and used to quantify the Na
+
partitioning between shoot and root. Among the
indices, stress tolerance index was found useful a
s a selection criterion. Furthermore, the
tolerant genotypes had higher
K
+
/Na
+
ratio in shoot and root with greater SFI, indicating
that most of Na
+
was stored in their roots. Although peroxidase and superoxide dismutase
were enhanced under salinity condit
ions in both sensitive and tolerant genotypes, only
Catalase (CAT) activity was found to be promoted in tolerant lines/cultivars. Proline
accumulation did not appear to be related to salinity tolerance in sorghum lines/cultivars.
Overall, our findings sugg
ested that salinity tolerance in sorghum genotypes was not only
associated with Na
+
exclusion from the shoot, but also with the enhancement of CAT
activity.
Keywords
: Catalase, Proline, Storage factor index, Stress tolerance index
