Agriculture Reference
In-Depth Information
Table 1. Effect of the different Al, Cd and Cu
treatments on leaf traits of barley seedlings
Genotypes
LA (cm
2
.
plant
-1
)
Treatments
LDW (g .
plant
-1
)
LFW (g .
plant
-1
)
LWC (g/g)
pH 6.5
65.2
0.171
0.553
0.691
pH 4.5
63.1
0.163
0.516
0.684
Al
59.4
0.131
0.351
0.627
Gebeina
Al
+ Cu
56.2
0.121
0.306
0.601
Al + Cd
56.1
0.120
0.312
0.603
Al + Cu + Cd
58.7
0.130
0.343
0.623
pH 6.5
66.1
0.169
0.538
0.688
pH 4.5
63.4
0.160
0.497
0.678
Shang 70-
119
Al
57.9
0.124
0.314
0.605
Al
+ Cu
54.6
0.112
0.255
0.561
Al + Cd
54.1
0.110
0.248
0.557
Al + Cu + Cd 51.4 0.101 0.207 0.532
LSD0.05 Between genotypes 1.2 0.003 0.033 0.021
LSD0.05 Between treatments 2.3 0.008
0.039
0.019
LA, leaf area; LDW, leaf dry weight; LFW, leaf fresh weight; LWC, leaf water content
=( LFW -LDW)/LFW.
3.2. Chlorophyll Contents
Chlorophyll absorbs radiant energy, which is used for photosynthesis, so chlorophyll
content in the cell has been used as a parameter of following plant growth. In the present
investigation, the total chlorophyll contents, chlorophyll a and b contents all decreased under
stress condition, while the decreases in chlorophyll a contents is more obvious than that in
chlorophyll b content expressed as the ratios of chlorophyll a/b (table 2), which was in
agreement with the reports by Woolhouse (1974) who showed that chlorophyll content
decreased as leaf was senescent, and chlorophyll a content decreased noticeably as compared
with chlorophyll b. Khudsar et al (2001) found that the contents of chlorophyll a and b were
reduced under the effect of Cd toxicity. In addition, Stobart et al. (1985) suggested that heavy
metals could inhibit chlorophyll biosynthesis at the level of photochlide reductase. Metals
combinations induced the further reduction in chlorophyll content when compared with the
Al alone treatment, especially for Shang 70-119. However, ternary metals combination
produced different effects in two barley genotypes, thus, the more reductions were observed
in Shang 70-119, while the adverse results were detected in Gebeina when compared with
that of the binary metals combinations.
