| Pak. J. Bot., 37(3): 651-660, 2005. | Back to Contents | ||||
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Updated: 09-07-09 | ||||
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EFFECT OF TEMPERATURE ON SEED GERMINATION OF SEVEN CALLIGONUM SPECIES JUN REN*, JIN ZIXUE **, LING TAO*
Abstract:
Greenhouse experiments were conducted to study the effects of temperature
on the seed germination of 7 Calligonum species, dominant shrubs
in shifting sand dunes and stabilized sand fields in the northern desert
of China. In August 1998, seeds of Calligonum were collected
and exposed to different temperatures. The results suggested that there
is no relationship between the temperature treatment and germination
rate. Optimum germination occurred at 20°C. Minimum germination
time of 3-4 days was recorded for C. junceum, C. leucocladum, C.
gobicum and C. mongolicum at 22°C; approximately 3 days
for C. arborescens and C. caput-medusae and 6 days for
C. rubicundum. The 12°C treatment significantly increased
the minimum germination time from those recorded at 20°C and 22°C
by about 4-9 days for all seven species. Calligonum species germinated
readily between 18-22°C. Maximum germination occurred at 20°C
in C. gobicum and C. arborescens and at 22°C in C. junceum, C.
leucocladum, C. rubicundum, C. mongolicum and C. caput-medusae.
Seeds germinated faster at higher constant temperatures.
College of Environmental and Municipal Engineering, Institute of Environmental
Ecology, Lanzhou Jiaotong University,
Lanzhou 730070, P. R. China. |
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