Genetically engineered corn express

Genetically engineered corn expressing crystalline proteins for insect control and encoded by genes
derived from soil bacterium Bacillus thuringiensis (Bt) are widely adopted in the United States. Among the
seven different events of Bt corn available commercially, YieldGard® Rootworm (event MON863) expresses
a variant of the cry3Bb1 protein in the root tissue to control corn rootworm larvae. Nematodes
reside in the rhizosphere and are potentially exposed to Cry3Bb1 toxins exudated from roots of Bt corn.
We test the hypothesis that coleopteran-active Bt corn does not affect non-target soil nematodes.
Experimental treatments were: 1) a Bt hybrid, 2) a non-Bt isoline treated with a conventional soil
insecticide, and 3) a non-Bt isoline without insecticide. Nematodes were extracted from soil samples
collected prior to planting (May), at peak anthesis (August), and after harvest (October) in 2003 and
2004, enumerated and identified to genus. A total of 73 nematode genera were encountered in soil and
litter combined. During the growing season, maturity index values and relative abundance of fungivorous
nematodes were greater in the Bt hybrid than the non-Bt isoline with or without insecticide. Nematode
trophic diversity values were greater in the Bt hybrid than non-Bt isoline with insecticide and this effect
continued through the following spring. Abundance of nematode predators increased two weeks after
insecticide was applied to non-Bt isoline, but decreased without insecticides on either Bt or the non-Bt
isoline. In decaying roots of corn treatments, maturity index values and the relative abundance of
nematode predators was greater in the Bt hybrid than non-Bt isoline with insecticide. Effects at the
overall community structure and nematode genera varied more by seasonal phenology than corn
treatment. The isoline with insecticide had more non-target effects on nematode communities than the
Bt hybrid. This treatment increased the relative abundance of predaceous nematodes temporarily but
eventually reduced successional maturity by harvest time, which continued to decline during the winter
in both soil and decaying corn roots

ผลลัพธ์ (แอฟริกา) 1:

Ontwerp koring geneties uitdrukking kristallyne Proteïene gekodeer deur gene vir Insekbeheer en
grond bakterie Bacillus thuringiensis afgelei van (Bt) word wyd aanvaar word in die Verenigde State. Onder die
verskillende gebeure van Bt-mielies Sewe kommersieel beskikbaar is, YieldGard® wortel boorder (MON863 gebeurtenis) spreek
die Cry3Bb1 proteïen in 'n variant van die koring wortel boorder larwes beheer om wortel weefsel. Aalwurms. Woonagtig in die rhizosfeer en potensieel blootgestel aan Cry3Bb1 gifstowwe Exudated van Roots van Bt-mielies. Ons Toets die hipotese dat Coleopteran-aktiewe Bt mielies raak nie nie-teiken grond nematodes eksperimentele behandelings was: 1) 'n Bt baster, 2). 'n nie-Bt Isoline behandel met 'n konvensionele grond Insekdoder, en 3) 'n nie-Bt Isoline Sonder insekdoder. Aalwurms is van grondmonsters onttrek voor Collected plant (Mei), op Anthesis Peak (Augustus), en na Harvest (Oktober) in 2003 en 2004, vervat en geïdentifiseer genus. 'N Totaal van 73 nematode genera ondervind in die grond en rommel gekombineer. Gedurende die groeiseisoen, rypheidsindeks waardes en relatiewe oorvloed van Fungivorous nematodes was in die Groter as die nie-Bt baster Bt Isoline met of sonder insekdoder. Nematode trofiese Diversiteit waardes was in die Groter as die nie-Bt baster en Bt Insekdoder met hierdie Isoline Effek deur voortgesette die volgende lente. Twee weke na Oorvloed van nematode roofdiere Verhoogde Insekdoder Toegepaste nie-Bt was Isoline, maar verminder Sonder insekdoders op óf Bt of nie-Bt die Isoline. Wortels van koring in verrottende behandelings, rypheidsindeks waardes en die relatiewe oorvloed van nematode roofdiere was in die Groter as die nie-Bt baster Bt Isoline met insekdoder. Effekte by die algehele struktuur Gemeenskap nematode genera en meer gevarieerde as koring deur seisoenale fenologie Behandeling. Insekdoder met die Isoline het meer effek op nie-teiken nematode gemeenskappe as die Bt baster. Behandeling verhoog relatiewe oorvloed van predatoriese dit die nematodes tydelik, maar uiteindelik deur opeenvolgende Volwassenheid Harvest tyd verminder, wat voortgegaan om te daal gedurende die Winter in beide grond en verrottende koring Roots.