Abstract:
Drought stress is the major limitation for crop yie
ld, which depending on the time of
occurrence, could decrease the number of grain as w
ell as their weight. Barley (
Hordeum
vulgare
L.) is one of the tolerant cereals that its grain
components have an important role
in human and animal nutrition; however, physical an
d biochemical properties of grains
affected through drought stress are still poorly un
derstood. In this study, barley
genotypes (n= 6) with different levels of drought t
olerance were studied in a 2-year field
experiment under well-watered and terminal drought
stress conditions. In order to
measure physical properties of grains, digital imag
es were taken and some morphological
features were obtained by using Image Analysis Tool
box of MATLAB software.
Biochemical properties of grains were also measured
. Results proved that size, weight and
also quality of the grains were significantly affec
ted by drought stress (P< 0.01). Grain
starch content decreased and protein content increa
sed under drought stress at anthesis
stage in all genotypes, but drought-sensitive genot
ypes interestingly had more percentage
increase in protein content. Furthermore, genotypes
varied in total sugar, sucrose, glucose
and fructose content. Drought stress affected grain
size and finally 1,000-grain weight of
barley genotypes by reducing area and minor axis le
ngth of grains. Correlations between
1,000-grain weight and minor axis length, grain are
a, starch and sucrose content were
significant (P< 0.01). These results emphasized in
both conditions that size-dependent
features of grain particularly minor axis length an
d area may be serving as useful traits
for estimation of 1,000-grain weight and biochemica
l properties in barley.
Keywords:
Grain size,
Hordeum vulgare
L., Image analysis, Protein, Starch.
