Vol. 54—2000 - NorthEastern Weed Science Society

POLLEN TRANSPORT FROM GENETICALLY MODIFIED CORN
J.M. Jemison, Jr.' andM. Vayda'
ABSTRACT
Concern over the transport of genetically engineered (GE) com pollen in the U.S. is
growing. Organicproducersparticularlyorganicdairyandsweet com growersfearthe
loss of theirorganiccertificationif GEproteinsarefoundin theircom. Althoughcom
pollen grainsare among the largest and heaviest of windpollinated plants, transport is
possible. Criticsof GEfrequentlyreferto the"genecloud"of mutantcom pollen
travellingdistancesof manymiles to crosspollinateandcontaminatenon-GEcom. In
the sununer of 1999, we planted four research plots to com between May 15 and May 17.
An 83-day Roundup-Ready (RR) com (DeKaib 335 RR) hybrid was usedfor two of these
studies, andone of these studies wasvandalized in August after the com had shed pollen.
These studieswere locatedsidebyside. Inthe othertwo studies,(a phosphorusfertility
trial and another weed control study), we planted another 83-day hybrid, Agway 144.
Becauseof the close plantingdatesandthesamematurities,thisprovidedus withthe
opportunity to evaluate the potential cross pollination of GE com pollen with standard
com silage hybrids.
The two studies with RR com located side by side were approximately 37,190 ft' in total
area and were located between the two other com trials. The phosphorus study was
approximately 12,000 ft' andwas located 175 feet east of the RR study. The prevailing
winds come from the southwest, andthis study should represent a worst-casescenario for
cross pollination. The other weedcontrol study was located 1150 feet southwest of the
RR study. The size of that plot was 11,520 ft'. This represents the lowest chance of
gettingcrosspollination. To evaluatecross-pollinationandthe effect of position in the
field, we divided each study into threeareas: closest to the field, a middle seetion anda
seetion farthest away from the GE pollen source. Four replicate samples were collected
from each study. We collected com from the RR study as well.
layoutis presentedbelow.
A figure showing the
Com was harvested from each studyon September 17 to provide seed to germinate in the
greenhouse. We collected 100 ears from each location within each study area. Com ears
were dried in a greenhouse until dry enough to germinate. Seedswere sown in 4.5 ft'
greenhouse flats with porting soil at half inch spacing or approximately 170 seedslflat.
We are currently at this stage in theresearch. Plant emergence will be recorded for each
flat. At the 2 leaf stage, plants will besprayed by hand with a 0.5% solution of Roundup
Ultra. Plants that survive will be scored, andthe processwill be repeated as many times
as possible to increasethe samplesize as highas possible.
At this time, we have no results to present. Results will be available at the meeting.
1AssociateExtensionProfessorand2ProfessorofBiochemistry- Universityof Maine
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