Assessing the Ecological Fitness of Recipients

Weis, Arthur E.

doi:10.1002/9780470988497.ch6

Cited by 10 publications

(9 citation statements)

References 78 publications

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“…Models to predict ecological consequences of transgene movement from genetically modified (GM) crops to wild relatives require a measure of hybrid fitness (Hails & Morley 2005; Weis 2005). GM rapeseed ( Brassica napus 2n = 4x = 38) has cross‐compatible relatives over most of its global range (Raybould & Gray 1993; Scheffler & Dale 1994; Ellstrand et al .…”

Section: Introductionmentioning

confidence: 99%

Fitness of hybrids between rapeseed (Brassica napus) and wild Brassica rapa in natural habitats

et al. 2006

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Fitness of hybrids between genetically modified (GM) crops and wild relatives influences the likelihood of ecological harm. We measured fitness components in spontaneous (non-GM) rapeseed x Brassica rapa hybrids in natural populations. The F1 hybrids yielded 46.9% seed output of B. rapa, were 16.9% as effective as males on B. rapa and exhibited increased self-pollination. Assuming 100% GM rapeseed cultivation, we conservatively predict < 7000 second-generation transgenic hybrids annually in the United Kingdom (i.e. approximately 20% of F1 hybrids). Conversely, whilst reduced hybrid fitness improves feasibility of bio-containment, stage projection matrices suggests broad scope for some transgenes to offset this effect by enhancing fitness.

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Section: Introductionmentioning

confidence: 99%

Fitness of hybrids between rapeseed (Brassica napus) and wild Brassica rapa in natural habitats

et al. 2006

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“…Usually, the low fertility of early-generation hybrids has been considered to be the major hindrance for introgression to take place (e.g. Weis, 2005). For instance, F 1 hybrids from certain crop–wild crosses of rice showed reduced fertility (Ellstrand et al , 1999).…”

Section: Discussionmentioning

confidence: 99%

Morphology and fitness components of wild × crop F₁hybrids ofSorghum bicolor(L.) in Ethiopia: implications for survival and introgression of crop genes in the wild pool

Adugna

Bekele

2013

Plant Genet. Resour.

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Natural hybridization between wild/weedy and crop species often results in rare hybrids, which can be more weedy and difficult to control. Moreover, the advent of transgenic crop plants raises questions of biosafety risk assessment on the consequences of rare hybrids with possible fitness enhancing genes on the environment. This study aimed at measuring the fitness components of wild -crop sorghum hybrids for various juvenile survival and adult morphological and fertility characters as part of the risk assessment of transgenic sorghum in Africa where the crop was believed to have first domesticated and serves as the major staple. Out of a pool of hybrids made in 2010 from 23 wild sorghum accessions and two released cultivated sorghum varieties using hand emasculation techniques, seven were selected for the field study of their fitness components in 2011. The study confirmed that crop -wild hybrids of sorghum are fertile. Two approaches were followed (relative fitness and mid-parent heterosis) which showed that most of the hybrids were as fit as their wild parents, and in some cases they showed mid-parent heterosis for the measured traits. The results of this study highlighted a potential risk that hybrids carrying crop genes (including herbicide resistance transgenes) could pose because they could be more weedy than their wild/weedy parents if transgenic sorghum is deployed in regions where the wild and cultivated sorghum populations coexist, such as in Ethiopia and in other parts of Africa.

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“…Theoretical studies (Haygood et al 2004) revealed that even low hybridization rates (on the order of 10 −3 ) might allow for the rapid escape and establishment of a moderately favored transgene. Transgenes could have a significant ecological advantage if they increased the recipient's interspecific competitiveness, increased its ability to invade an expanded niche range, or precipitated a severe decline in herbivores or plant pathogens that limit its growth (Weis 2005). Not all such changes would necessarily promote weediness/invasiveness.…”

Section: Fecundity and Fitnessmentioning

confidence: 99%

“…Not all such changes would necessarily promote weediness/invasiveness. For example, a gene that increases interspecific competitive ability could induce a genetic sweep through the recipient population without changing its abundance and density relative to the larger community, although the genetic diversity and structure could be affected (Weis 2005). Thus, predictions on the implications of transgene spread require some knowledge of the demography and genetic structure of the recipient populations, how they interact with other species, and what factors limit their spread.…”

Section: Fecundity and Fitnessmentioning

confidence: 99%

Gene Flow, Invasiveness, and Ecological Impact of Genetically Modified Crops

Warwick¹,

Beckie²,

Hall³

2009

Annals of the New York Academy of Sciences

149

119

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The main environmental concerns about genetically modified (GM) crops are the potential weediness or invasiveness in the crop itself or in its wild or weedy relatives as a result of transgene movement. Here we briefly review evidence for pollen- and seed-mediated gene flow from GM crops to non-GM or other GM crops and to wild relatives. The report focuses on the effect of abiotic and biotic stress-tolerance traits on plant fitness and their potential to increase weedy or invasive tendencies. An evaluation of weediness and invasive traits that contribute to the success of agricultural weeds and invasive plants was of limited value in predicting the effect of biotic and abiotic stress-tolerance GM traits, suggesting context-specific evaluation rather than generalizations. Fitness data on herbicide, insect, and disease resistance, as well as cold-, drought-, and salinity-tolerance traits, are reviewed. We describe useful ecological models predicting the effects of gene flow and altered fitness in GM crops and wild/weedy relatives, as well as suitable mitigation measures. A better understanding of factors controlling population size, dynamics, and range limits in weedy volunteer GM crop and related host or target weed populations is necessary before the effect of biotic and abiotic stress-tolerance GM traits can be fully assessed.

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Assessing the Ecological Fitness of Recipients

Cited by 10 publications

References 78 publications

Fitness of hybrids between rapeseed (Brassica napus) and wild Brassica rapa in natural habitats

Fitness of hybrids between rapeseed (Brassica napus) and wild Brassica rapa in natural habitats

Morphology and fitness components of wild × crop F₁hybrids ofSorghum bicolor(L.) in Ethiopia: implications for survival and introgression of crop genes in the wild pool

Gene Flow, Invasiveness, and Ecological Impact of Genetically Modified Crops

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Assessing the Ecological Fitness of Recipients

Cited by 10 publications

References 78 publications

Fitness of hybrids between rapeseed (Brassica napus) and wild Brassica rapa in natural habitats

Fitness of hybrids between rapeseed (Brassica napus) and wild Brassica rapa in natural habitats

Morphology and fitness components of wild × crop F1hybrids ofSorghum bicolor(L.) in Ethiopia: implications for survival and introgression of crop genes in the wild pool

Gene Flow, Invasiveness, and Ecological Impact of Genetically Modified Crops

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Product

Resources

About

Morphology and fitness components of wild × crop F₁hybrids ofSorghum bicolor(L.) in Ethiopia: implications for survival and introgression of crop genes in the wild pool