|
Full Length Research Paper
|
|
Dispersal distance of rice
(Oryza Sativa L.) pollen at the Tana River delta in
the coast province, Kenya
James I. Kanya1*,
Jenesio I. Kinyamario1,
Nelson O. Amugune1 and Thure P. Hauser2
1School
of Biological Sciences, University of Nairobi, P. O. Box
30197-GPO, Nairobi, Kenya.
2Department
of Agriculture and Ecology, University of Copenhagen,
Rolighedsvej
21, DK- 1958, Frederiksberg, Denmark.
*Corresponding author. E-mail:
jiykaya@uonbi.ac.ke.
Accepted
12 March, 2009 |
|
|
|
Abstract |
|
|
|
Rice is a staple food in Kenya and its production needs to be
increased. Genetically modified (GM) rice may be a solution,
but before it can be introduced, potential ecological
impacts, such as pollen mediated gene flow from GM rice to
non-GM rice or to its wild indigenous relatives, need to be
understood. Pollen dispersal in rice (Oryza sativa)
was studied in the Tana River district in the coast province
of Kenya. O. sativa seedlings were planted in a 50 m
diameter circular experimental design. Pollen traps (glass
slides coated by vaseline attached to a board) were used to
measure pollen flow at 2 heights and at increasing distances
from the source plot. Pollen dispersal decreased rapidly
with increasing distance from the pollen source up to 250 m,
no pollen was found at 300 m. There was a significant (P <
0.05) difference in pollen dispersal in different
directions, which correlated with the prevailing wind
direction (south, occasionally east). Effect on wind speed
and humidity could not be evaluated as they were relatively
stable during the sampling period. No overall difference (P
> 0.05) in pollen count between upper and lower pollen
traps. The
highest daily pollen count was observed between 11:00
am and 12:00 noon, and at a narrow range of temperatures 28
± 2ºC. On the basis of these data, an adequate
isolation distance of more than 250 m should be considered
to minimize chances of gene flow from transgenic rice to
conventional or wild rices.
Key
words:
Pollen dispersal, gene flow, Oryza sativa, rice,
genetically modified. |
|
