Agriculture Reference
In-Depth Information
There.are.a.number.of.challenges.for.commercialization.of.transgenic.horticultural.
crops..The.biggest.obstacle.is.probably.high.costs.associated.with.food.and.environ-
mental. safety. testings. required. by. federal. agencies.. While. traditionally. bred. crop.
plants.are.not.subjected.to.any.testing.or.regulations,.testing.required.for.a.deregula-
tion.approval.of.a.transgenic.crop.is.extensive,.and.can.cost.$10-20.million.per.novel.
gene.in.a.crop.variety.
5
.Because.each.horticultural.plant.species.has.many.varieties.and.
each. variety. represents. a. small. market. value,. recovering. high. costs. associated. with.
the.required.testing.can.be.a.challenge..As.a.consequence,.commercial.horticultural.
companies.are.not.enthusiastic.to.pursue.transgenic.horticultural.crops.
1
Another. hurdle. for. commercialization. of. transgenic. horticultural. crops. is. envi-
ronmental.and.food.safety.concerns.
4
.One.example.is.transgenic.glyphosate-resistant.
creeping.bentgrass..The.herbicide-resistant.bentgrass.should.make.weed.control.more.
effective.and.also.enhance.the.uniformity,.quality,.aesthetics,.and.playability.of.golf.
course. turf.
6
. Studies. by. the. U.S.. Department. of. Agriculture. (USDA). Animal. and.
Plant.Health.Inspection.Service.(APHIS).suggest.that.(1).there.appear.no.major.unin-
tended.effects.resulting.from.the.introduction.of.the.glyphosate.resistance.gene.into.
the.creeping.bentgrass.genome,.(2).the.transgenic.bentgrass.is.not.sexually.compatible.
with.any.federally.acknowledged.threatened.or.endangered.species.or.with.any.spe-
cies.on.the.federal.noxious.weed.list,.and.(3).the.transgenic.bentgrass.does.not.differ.
in.pest.and.pathogen.susceptibility.or.resistance.from.its.parent.
7
.However,.Watrud
8
.
reported.that.pollen.of.the.herbicide-resistant.transgenic.creeping.bentgrasses.trav-
eled.up.to.21.km.and.the.pollen.could.fertilize.wild.bentgrasses.and.a.close.relative,.
redtop. (
Agrostis gigantean)
.. Reichman
9
. detected. nine. herbicide-resistant. creeping.
bentgrass.plants.that.were.found.up.to.3.8.km.beyond.the.control.area,.and.they.there-
fore.concluded.that.there.were.both.seed.dispersal.and.pollen-mediated.crossing.with.
wild.creeping.bentgrass..Although.the.herbicide-resistant.creeping.bentgrass.displays.
no.increase.in.vegetative.spread.or.relative.itness,
10
.the.public.opposition.to.dereg-
ulation. of. the. herbicide-resistant. bentgrass. is. strong.. It. appears. that. the. transgenic.
herbicide-resistant.bentgrass.has.a.long.way.to.go.before.it.is.marketed.
6
CANDIDATE MOLECULAR STRATEGIES ADDRESSING
CONCERNS OVER TRANSGENIC HORTICULTURAL CROPS
Gene-based. technologies. that. can. reduce. environmental. and. food. safety. concerns.
over.transgenic.plants.could.facilitate.commercialization.of.transgenic.horticultural.
crops..A.number.of.transgene.containment.technologies.that.may.reduce.gene.low.
have.been.reported.
11-15
.Some.of.these.technologies.should.also.be.useful.to.address.
food.safety.concerns.on.transgenic.horticultural.crops..In.this.chapter,.we.will.pro-
vide.a.brief.review.on.some.of.these.molecular.technologies.and.discuss.their.poten-
tial.applications.and.limitations.in.horticultural.crops.
m
ale
and
f
emale
S
terIlIty
Male.sterility.is.deined.as.the.inability.of.pollen.to.fertilize.the.ovum,.and.female.
sterility. is. deined. as. the. inability. of. the. female. organ. to. be. pollinated. or. to. pro-
duce.seeds.upon.pollination..In.both.cases,.sterility.can.be.caused.by.inadequacy.in.
Search WWH ::
Custom Search