New Genetics, Food and Agriculture: Scientific ... - ArgenBio

N E W G E N E T I C S, F O O D A N D A G R I C U LT U R E 27d es i ra ble, but is diffi cult to ob tain in many instan ces. Al s o,both the risks and the benefits of new technologies need to beconsidered, so as to develop a picture of the options availableand the choices implied.The potential environmental impacts of modern geneticsm ay be thought of in a hierarc h i cal man n e r, from co n s e-quences for the crop (or other genetically modified species)and its re l atives, th rough to inte ra c tions at the co m m un i tylevel, and at the ecosystem level.Small or large genetic modifications may perturb the environment.It is difficult to extrapolate from the environmentali m pact as s essments of the fi rst generation of geneti ca l l ymodified crops (that are mainly the result of single gene modificationsfor pest or disease resistance) to emerging productsth at may be the result of genetic mod i fi cations to re g u l atemore complex traits. For example, future traits in plants maybe changes in tolerance to abiotic and biotic stresses, alterednutritional content (e.g. vitamins, oil, starch) and/or modifiedbiochemical pathways to produce compounds for medical orindustrial uses (US NAS 2000).ENVIRONMENTALLY FRIENDLY PRODUCT DESIGNThe greater understanding of the environmental risks andbe n e fits posed by modern geneti cs may lead to the be tte rdesign of future crops. For example, where gene flow is a riskin out-crossing crops growing in their centre of diversity, closeto wild relatives with which they may cross, it may be possibleto include genetic mechanisms of pollen inco m pati b i l i ty tolimit the risk of gene fl ow. Also the incre ased avai l a b i l i ty oftissue-specific promoters enables genes to be expressed onlyin the part of the plant where required (e.g. leaves) and not inthe pollen or other parts of the plant, thus reducing the risk ofinadvertent gene transfer.Where crops are to be used for industrial purposes to produce products such as va cc i n es, or indus trial pol y m e rs, th ec rop of choice should be one with which th e re is no risk ofgene flow to related edible crops or wild species in the area ofcultivation (Johnson in CGIAR 2000a).Issue 1. Direct effects on biodiversityand the environmentModern geneti cs is being used in the improvement ofcrops, trees, livestock, fish and microbial species used in agriculture.Each may have direct effects on the environment.Plants: Several issues need to be considered in relation tothe cu l tivation of pl ants in the env i ronment. These are th epotential for:• Gene tran s fe r, the movement of genes from a cu l tivate dc rop th rough pollen out - c rossing to form hybrids withlocal landraces and/or related wild species.• Weed i n es s, the te n d e n cy of pl ants (or their derive dhybrids/backcrosses formed with related or wild species)to spread beyond the field where first planted and becomeestablished as a weed amongst crops or invasive species inother habitats.• Trait effects, the effects of specific traits that may be potentiallyharmful to non-target organisms and damage theirrole in ecosystem function.• Ex p ression of genetic material from path og e n s, such asvirus vectors.• Un e x pec ted effec t s, due to genetic and ph e n o typic var i-ability, and the tendency of the plant to exhibit unexpectedcharacteristics after genetic recombination.• Worker safety upon exposure to new products.These risk issues for the release of plants into the environmentare similar in kind, whether the plants are the result oftra d i tional crop improvement or modern geneti cs, or th eyresult from the introduction or escape of ornamental crops.Trees: T h e re are po te n tially direct env i ro n m e n tal effe c t sfrom the release of genetically modified trees into the environmentthat are similar to those affecting plants. There arealso added concerns, given the long life cycle of trees.M i c roo rg an i s m s : The use of microo rg anisms in food produc tion is usually in co n tained situ ati o n s, such as fe r m e n tati o np roces s es. There is also po te n tial for their use in the env i ro n-ment. For exam ple, spe c i fi cally des i gn e d, geneti cally improve dm i c roo rg anisms may be re l e ased into the env i ronment as biolog i cal co n trol agents against diseas es, pests and weeds.