Biology Reference
In-Depth Information
A
B
D
C
F
E
Figure 10:
Microcycle akinete formation in
Anabaena torulosa
. Accumulation of granular contents in the hormogones leading
to microcycle akinete formation circumventing vegetative growth in
A
.
torulosa
. (A), (B) in nitrate medium, 18th day; (C), (D)
in nitrate with citrate, 20th day; (E), (F) in nitrate medium, 18th day. A-f x 1,950 (From Sarma and Malhotra, 1989).
IV. AKINETE GERMINATION IN RELATION TO BLOOM DEVELOPMENT
A number of investigations dealt on the role of akinetes as potential source of inoculum for
development of harmful algal blooms. Akinetes of
A
.
fertilissima
and
Anabaenopsis arnoldii
from the
sediments of Sambhar Salt Lake, the largest lake in India situated in east-central Rajasthan, exhibited
97% and 50% germination potential, respectively (Reddy, 1983b). The akinetes of
No. spumigena
in
the sediments of Peel-Harvey estuarine system in western Australia constituted the chief source of
inoculum for bloom formation (Huber, 1984). Cmiech
et al
. (1984) studied the emergence of blooms of
A
.
spiroides
,
A
.
fl os-aquae
,
A
.
solitaria
,
G
.
echinulata
and
Aph
.
fl os-aquae
and suggested that in the
lake of York shire (New York), the surface populations of
A
.
solitaria
are generally removed by the
germination of 40% of the akinetes immediately after their formation. Akinetes of
Aph
.
ovalisporum
,
deposited in the sediments of Lake Kinneret, Israel, constituted a source of development for the
ensuing year (Hadas
et al
., 1999). Head
et al
. (1998, 1999) attributed the development of
A
.
solitaria
