Transgenic Fruit Crops in Europe - Transgenic Horticultural Crops: Challenges and Opportunities - page 130

FIGURE 5.1 ( See color insert. ). Dutch.ield.trial.with.GM. apples. overexpressing.the. hth .
gene.from.barley..GM.apple.plants.of.the.cultivars.'Gala'.and.'Elstar'.were.tested.for.their.
resistance.to.apple.scab,.ire.blight,.and.powdery.mildew..The.ield.trial.was.inished.in.2008..
The.maximum.area.of.the.site.was.3850.m 2 ..(The.igure.was.kindly.provided.by.Frans.Krens.
from.PRI.Wageningen,.the.Netherlands.)
Another. ield. trial. has. been. carried. out. in. Sweden. (notiication. numbers.
B/SE/99/1644. and. B/SE/04/1227).. This. ield. trial. was. performed. with. GM.
plants. of. the. apple. rootstocks. M26. and. M9/29. transformed. with. the. rolB . gene. of.
Agrobacterium rhizogenes .to.improve.rooting.ability..The.GM.rootstocks.were.char-
acterized, 5-8 . planted. into. the. ield. in. 2001,. and. budded. with. different. apple. culti-
vars.including. 'Aroma',. 'Jonagold',. 'Elstar',. 'Discovery',.and.'Elise'.in. 2002. 9 .The.
transformed.rootstocks.were.compared.to.non-GM.rootstocks.for.traits.such.as.tree.
growth,. tree. anchorage,. tree. size,. branching,. leaf. form. lowering,. fruit. set,. fruit.
quality,.transgene.stability,.and.systemic.transport.of.transgene.products. 9,10
In.order.to.accelerate.classical.breeding,.molecular.techniques.can.be.applied.
to. enrich. existing. commercial. apple. cultivars. with. functional. alleles. from. sexu-
ally. compatible. plants,. preventing. genetic. drag. and. keeping. the. genetic. makeup.
of. the. commercial. cultivar.. This. concept. is. termed. 'cisgenesis'. 11 . Cisgenesis . is.
deined.as.the.genetic.modiication.of.a.recipient.plant.with.natural.gene(s).from.
a.sexually.compatible.plant. 12,13 .In.cisgenesis,.no.foreign.genes.are.allowed.in.the.