Page 6 - Legume Genomics and Genetics

Legume Genomics and Genetics (online), 2010, Vol. 1, No.7, 34-40
http://lgg.sophiapublisher.com
Table 4 The agronomic traits of M3 treated by different concentrations of colchicine
Treatment (12 h) 0.4% colchicine 0.2% colchicine Control
Plant height (cm) 43.80aA 41.90aA 40.70aA
No. of nodes on mainstem 17.23aA 17.89aA 8.80bB
Starting nod of effective branch 1.65aA 1.59aA 0.93bA
Branch number 1.45aA 1.58aA 2.27aA
Pod length (cm) 7.47aA 7.38aA 6.80bA
Pod width (cm) 0.70aA 0.68aA 0.58bB
No. of pods per plant 19.69aA 21.75aA 11.09bA
No. of seeds per plant 79.49aA 91.60aAB 41.12bB
Yield per plant 14.36aA 16.35aA 6.81aA
100- seed weight (g) 18.20aA 19.84aA 10.92bB
Note: Different lowercases indicate significant (p<0.05), and with different capital letters are extra significantly different (p<0.01)
weight between treatments was significant, other traits
had little differences. The number of seeds per plant
treated by 0.2% concentration was relatively small, but
yield per plant was increased 33.98% than that with 0.4%
concentration, and 100-seed weight was increased 10.75%.
Therefore, the 0.2% colchicine was more appropriate for
the treatment.
Colchicine-treated M3 generation had no significant di-
fferences in plant height, branch number of main stem
and pod number per plant compared with the control
(Table 4), while significant differences occurred at 1%
level in the of number of nodes on main-stem , pod width
and 100-seed weight. The values of main-stem node
number, main-stem branch number, pod number per plant,
seed number per plant, single-plant yield and 100-seed
weight by the treatment of 0.2% concentration are higher
than treated by 0.4% concentration. Meanwhile, by com-
prehensive analysis on plant survival rate, seedling rate,
mutant frequency and agronomic traits of two kinds of
treatments, 0.2% colchicine was optimal for mutagenesis
of azuki bean.
1.2 Variation types of M3 generation
Variations occurred in plant traits of colchicines-induced
M2 generation. The variations of leaf traits, plant archi-
tecture, pod colour and seed traits, etc. such as light
green leaf, sword leaf, kidney-shaped leaf, higher plants,
thick stalk, black pod, dark red seed and big seeds
were obtainned by treatment with different concentra-
tions of colchicine. M3 mutant types would be different
to a certain degree. 0.4% colchicines-treated variations
were more abundant than those by treatment of 0.2%
concentration, some unique mutant types like light
green leaf, sword leaf, glave kidney leaf, higher plant,
few branches, thick stalk, black pod, dark red seed and
big seed appeared (Table 5).
1.2.1 Leaf variation
Jingnong 6 has ovate leaves, the mutants of sword leaf,
small heart-shape leaf and kidney leaf were produced
in M3 generation. Leaf-shape mutation frequency treated
with 0.4% colchicine was 12.92%., A total of 19 plants
of sword leaf, 10 small heart-shape leaf and 12 kidney
leaf plants were found (Figure 1), including 7 of upper
glave leaf and lower kidney leaf. The mutants of 17
kidney leaf and 6 small heart-shape leaf appeared in the
treatment of 0.2% colchicine, with the leaf-shape mutation
frequency of 2.40%.
Figure 1 Leaf shape mutants in M3 generation of azuki bean
Note: A: JN6 Control; B: Kidney leaf; C: Sword leaf; D: Small
heart-shape leaf
In M3 population treated with the 0.4% colchicine, 9
deep-green leaf plants, 8 light green leaf, 3 new leaf
yellowing and 4 yellow spot leaf plants were generated
with the leaf-color mutation frequency of 2.40%. In
0.2% colchicine-treated M3 population, two plants of
deep-green leaf, two of new leave etiolated plants and
one of yellow spot leaf appeared with the leaf-color
mutation frequency of 0.50% (Figure 2).
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