Figure 3 - uploaded by Mikihisa Umehara
Content may be subject to copyright.
Comparison of morphological trait and carotene content among wild carrot, cultivated carrot and the hybrid. A. Photograph of wild carrot, hybrid, cultivated carrot (left to right). These plants were grown for five months in pots. Bar indicates 5 cm. B. Carotene content in leaves. C. Carotene content in taproot. Gray and black boxes show the contents of a-and b-carotene, respectively. Error bars represent SD with n=6.
Source publication
To establish a guideline for assessing the environmental effects of genetically modified (GM) crops, flows of genes from GM crops to their wild relatives should be understood. We investigated the gene flow between cultivated and wild varieties of carrot, Daucus carota, as a model plant system despite of the fact that no GM carrot is currently culti...
Contexts in source publication
Context 1
... has wild relatives called wild carrot. Leaves and flowers of wild carrot resemble those of cultivated ones but the taproot of wild carrot is thin and white ( Figure 3). Wild carrot has been known in Western countries as a weed and researched from the view point of weed (Georgia 1914;Frankton 1970;Sylwester 1960;Stachler and Kells 1997;Stachler et al. 2000). ...
Context 2
... Harumakigosun) by reciprocal crossing. The hybrids showed characteristic taproots, which were yellowish and intermediate of the wild and cultivated carrots in thickness ( Figure 3A). ...
Context 3
... contents of a-and b-carotene in the leaves and taproots of cultivated carrot, wild carrot and the hybrid were quantified by HPLC ( Figure 3B, C). In the leaves, the cultivated carrot contained less b-carotene than the wild carrot and the hybrid ( Figure 3B). ...
Context 4
... contents of a-and b-carotene in the leaves and taproots of cultivated carrot, wild carrot and the hybrid were quantified by HPLC ( Figure 3B, C). In the leaves, the cultivated carrot contained less b-carotene than the wild carrot and the hybrid ( Figure 3B). On the other hand, almost no a-carotene was detected in the leaves of the wild carrot and the hybrid. ...
Context 5
... the other hand, almost no a-carotene was detected in the leaves of the wild carrot and the hybrid. Although the total carotene contents in the leaves were similar in all of them, carotene was not detected in the taproots of the wild carrot, and the amount of b-carotene in the taproot of the hybrid was small ( Figure 3C). ...
Context 6
... approach was useful for estimating the flow of genes but could not determine the actual distance of gene flow. Yellow taproot of the hybrid is a useful morphological marker ( Figure 3A), but gene marker should be a more effective marker for monitoring the flow of genes. ...
Context 7
... most remarkable difference between wild and cultivated carrot was the color of taproot ( Figure 3A). Cultivated carrot contains high levels of carotene in taproot while the wild carrot has none. ...
Similar publications
Gene flow between populations adapting to differing local environmental conditions might be costly because individuals can disperse to habitats where their survival is low or because they can reproduce with locally maladapted individuals. The amount by which the mean relative population fitness is kept below one creates an opportunity for modifiers...
Citations
... Wild carrot is the ancestor of cultivated carrots and frequently has white or pale-yellow taproots. Wild carrots often grow next to cultivated carrot fields, and wild and cultivated carrots can cross each other without apparent barriers via a large diversity of insects such as bee and fly (Koul et al. 1989, Lamborn and Ollerton 2000, Magnussen and Hauser 2007, Rong et al. 2010, Umehara et al. 2005. Therefore, contamination of commercial cultivars by wild carrot is well known (Hauser and Bjørn 2001, Hauser 2002, Umehara et al. 2005, Wijnheijmer et al. 1989. ...
... Wild carrots often grow next to cultivated carrot fields, and wild and cultivated carrots can cross each other without apparent barriers via a large diversity of insects such as bee and fly (Koul et al. 1989, Lamborn and Ollerton 2000, Magnussen and Hauser 2007, Rong et al. 2010, Umehara et al. 2005. Therefore, contamination of commercial cultivars by wild carrot is well known (Hauser and Bjørn 2001, Hauser 2002, Umehara et al. 2005, Wijnheijmer et al. 1989. For carrot seed production by seed companies, contamination with white and wild carrots is one of the most important issues in seed quality control. ...
... According to NARO Genebank, 'Nakamura Senkou Futo' originated and was donated from Hokkaido, northern Japan (Genebank Project, NARO, JP No. 25816, https:// www.gene.affrc.go.jp/index_en.php) where wild white carrots, known as Queen Anne's lace, are frequently observed (Umehara et al. 2005). The examination of Y2_7 in 'Nakamura Senkou Futo' (Fig. 4) suggested that Y2_7 could detect wild white carrots grown not only in Melipilla and Cachapoal, Chile, but also in Hokkaido, Japan. ...
In carrot (Daucus carota L), the taproot colors orange, yellow and white are determined mostly by the Y, Y2, and Or loci. One of the most severe issues in carrot seed production is contamination by wild white carrot. To evaluate the contamination ratio, easily detectable DNA markers for white carrot are desired. To develop PCR-based DNA markers for the Y2 locus, we have re-sequenced two orange-colored carrot cultivars at our company (Fujii Seed, Japan), as well as six white- and one light-orange-colored carrots that contaminated our seed products. Within the candidate region previously reported for the Y2 locus, only one DNA marker, Y2_7, clearly distinguished white carrots from orange ones in the re-sequenced samples. The Y2_7 marker was further examined in 12 of the most popular hybrid orange cultivars in Japan, as well as ‘Nantes’ and ‘Chantenay Red Cored 2’. The Y2_7 marker showed that all of the orange cultivars examined had the orange allele except for ‘Beta-441’. False white was detected in the orange-colored ‘Beta-441’. The Y2_7 marker detected white root carrot contamination in an old open-pollinated Japanese cultivar, ‘Nakamura Senkou Futo’. This marker would be a useful tool in a carrot seed quality control for some cultivars.
... Moderate genetic differentiation among the subpopulations can be attributed to the mating system and probable bidirectional gene flow in carrot. The results of gene flow between wild and domesticated types were confirmed in the previous reports using SNP markers (Simon 2000;Rong et al. 2010;Iorizzo et al. 2013, Umehara et al. 2005). ...
Carrot (Daucus carota L.) is acknowledged as a highly valuable vegetable crop. Despite having high demand, limited breeding efforts have been made to develop the varieties and hybrids suitable to wider climatic conditions due to improper characterization of the available germplasm. An accession panel (AP) consisting of 144 accessions of five different root colors representing Asiatic and Western gene pools collected from different parts of India was utilized in the present study. This diverse AP was used to assess the population structure and genetic diversity from 80 polymorphic DNA markers distributed throughout the genome. Population structure, neighbor-joining (NJ) tree, and principal coordinate analysis (PCoA)-based diversity assessment divided the AP into three subpopulations/clusters. Greater than ninety percent polymorphism and the higher average polymorphic information content (͂> 0.50) coupled with higher gene diversity (He) indicating the broad genetic base of the population. Moderate to high Fst and gene flow (Nm) between the subpopulations revealed a moderate genetic differentiation among Indian carrot accessions owing to the highly outcrossing nature of carrot. Analysis of molecular variance (AMOVA) exhibited higher variation among individuals within the subpopulations (69.00%) or total populations (19.00%) than among the subpopulations (13%) as expected in the single Daucus species used here. The information obtained in the study would benefit the carrot breeders to explore the genetic diversity of the Indian carrots in the carrot breeding program for widening the genetic base and multi-color target trait improvement.
... In fact, wild carrot plants are highly outcrossed (96%) which indicates that the majority of the pollen reaching stigmas and fertilizing ovules comes from other plants in the population (Rong et al., 2010). In addition, carrot pollen can remain viable for days although 50% viability was observed after 12 hours (Umehara et al., 2005). ...
... Seed dispersal in carrots can occur via wind or animals with wind likely the most frequent dispersal agent (Lacey, 1981). Controlled air velocity studies indicate short distance dispersal of seeds via wind of a scale of a few meters (Umehara et al., 2005). The presence of spines on carrot seeds suggests seed dispersal by animals via transportation outside of the body (epizoochory) (Lacey, 1981;Umehara et al., 2005). ...
... Controlled air velocity studies indicate short distance dispersal of seeds via wind of a scale of a few meters (Umehara et al., 2005). The presence of spines on carrot seeds suggests seed dispersal by animals via transportation outside of the body (epizoochory) (Lacey, 1981;Umehara et al., 2005). Manzano and Malo (2006) demonstrated seed dispersal up to 400 km for carrot seeds attached to the fur of live sheep. ...
In this chapter, we first present characteristics of carrots that will affect gene flow and discuss dispersal via pollen by insect pollinators and via seeds by wind and animals. Although carrot is often referred to as a biennial, we introduce the various life history strategies observed in wild carrot populations as these can impact population growth and the range expansion of wild carrots over the landscape. We then review the studies of gene flow between crops, between crop and wild carrot and among wild carrot populations, concentrating on studies that used molecular markers. The consequences of these different types of gene flow (among cultivars, between crop and wild, and among wild) are then discussed. A major goal of biotechnology risk assessment for crops is to improve predictions of the fate of escaped genes either to other crop fields or to wild populations. We suggest as a priority for future studies to incorporate population dynamics with population genetics when modeling the fate of introduced genes. Improving our understanding of the factors that affect the spread of escaped genes will lead to the design of better management strategies to contain and limit their spread.
... Throughout most of the world, populations of wild carrots occur in close proximity to cultivated carrot fields (Magnussen and Hauser, 2007;Mandel et al., 2016;Umehara et al., 2005). Because cultivated and wild carrot belong to the same species and have similar flowering phenology, they can interbred and their close physical proximity raises concern about gene flow between cultivated and wild carrots (Grebenstein et al., 2013;Small, 1984;Umehara et al., 2005). ...
... Throughout most of the world, populations of wild carrots occur in close proximity to cultivated carrot fields (Magnussen and Hauser, 2007;Mandel et al., 2016;Umehara et al., 2005). Because cultivated and wild carrot belong to the same species and have similar flowering phenology, they can interbred and their close physical proximity raises concern about gene flow between cultivated and wild carrots (Grebenstein et al., 2013;Small, 1984;Umehara et al., 2005). In fact, bidirectional gene flow, from cultivar to wild and from wild to cultivar, has been detected in carrots (Hauser and Bjørn, 2001;Magnussen and Hauser, 2007;Mandel et al., 2016;Wijnheijmer et al., 1989). ...
... Cultivated and wild carrots are genetically differentiated (Grzebelus et al., 2014;Iorizzo et al., 2013;St Pierre and Bayer, 1991;Shim and Jørgensen, 2000) and such genetic differentiation should facilitate the identification of genetic markers to detect introgression. However, to date few markers have been identified (Umehara et al., 2005). In this study, we use genotyping by sequencing (GBS) to identify single-nucleotide polymorphisms (SNPs) between cultivated and wild carrot. ...
Abstract: Wild and cultivated carrots easily hybridize and cultivar genes can infiltrate wild carrot populations when pollinators move pollen from cultivated to wild carrots or when cultivar seeds migrate into wild carrot populations. Cultivar genes may then spread within and among wild carrot populations, a process called introgression. Wild carrots are widespread in the USA, can be weedy and have been declared invasive in some states. However, the extent of cultivar gene introgression into wild US carrot populations has yet to be quantified. The goal of this study is to identify genetic markers to detect the presence of cultivar genes in wild carrot populations. To reach this goal, we sampled leaf tissue from individuals in each of four wild carrot populations near a site that has been used to breed carrot cultivars for about 40 years. We also collected leaf tissue from individuals in wild carrot populations further away from the breeding site (3.3-20.8 km). We extracted DNA and performed genotyping by sequencing (GBS) on these samples. We identified single nucleotide polymorphisms (SNPs) from the combined samples of cultivated and wild carrots. We used these SNPs to examine, using fastSTRUCTURE, the population structure of wild and cultivated carrots and then only the wild carrot. We detected strong genetic differences between cultivated and wild carrots and between the near wild and far wild carrot populations. We identified markers capable of detecting introgression by comparing the gene frequencies of these SNPs between the far wild, near wild, and cultivar groups. Depending on the cultivars used in the analyses, we detected between 52 and 863 such markers. These markers did not aggregate over some chromosomes but were dispersed over all nine carrot chromosomes, suggesting that no chromosome was free of introgression.
... Because cultivated and wild carrots belong to the same species, they can easily hybridize (Grebenstein et al., 2013) and hybrids have been detected in wild carrot populations (Hauser and Bjǿrn, 2001;Magnussen and Hauser, 2007). Therefore, the introduction of a genetically modified carrot would create a high risk of gene transfer to wild carrots via hybridization (Umehara et al., 2005) and subsequent introgression could have serious consequences especially if the introgressed gene confers even a slight selective advantage to wild carrot or if it further increases its weediness. ...
Wild carrot was most likely introduced to North America from Europe as a weed. It has since spread to every state in the USA and has been declared invasive. Wild carrot can easily hybridize with cultivated carrots leading to the potential transfer of genes from the crop to wild carrot. Hybridization could become an issue if the genes transferred to wild carrot conferred a selective advantage and increased its competitiveness or invasiveness. A better understanding of the demography of wild carrot would permit the identification of the life history stages that most affect its population growth. Such knowledge would facilitate the design of management practices to best control its spread. In this study, we used data collected from wild carrot populations on reproduction, germination rate, overwinter survival and flowering rate to parameterize a stage structure model for a biennial lifecycle with a non-reproductive and a reproductive stage. Carrot populations were predicted to increase in size (λ>1), with growth rate (λ) of 1.9 when germination was low and 6.1 with high germination. Overwinter survival and flowering rate were the life history parameters that most affected population growth. Therefore, milder winter temperatures resulting from global warming could increase overwinter survival and the potential for spread of wild carrots. Effective management methods to control the spread of wild carrot and of the genes introduced into wild carrot populations should focus on lowering flowering rate and overwinter survival. For example, mowing should occur before flowering because our models predict that a single plant setting seeds could increase the population to 382 individuals within 3 years.
... Currently, no genetically engineered carrot products are available though much work has been carried out, see[29]; however, the carrot system is a good model for studying patterns of gene flow between crop-wild complexes. In many carrot-producing regions throughout the world, wild carrot populations can be found growing in close proximity to cultivated carrot fields[30,31]. Observations of wild carrot growing within cultivated carrot fields have also been reported[25,26,32]. ...
Studies of gene flow between crops and their wild relatives have implications for both management practices for cultivation and understanding the risk of transgene escape. These types of studies may also yield insight into population dynamics and the evolutionary consequences of gene flow for wild relatives of crop species. Moreover, the comparison of genetic markers with different modes of inheritance, or transmission, such as those of the nuclear and chloroplast genomes, can inform the relative risk of transgene escape via pollen versus seed. Here we investigate patterns of gene flow between crop and wild carrot, Daucus carota (Apiaceae) in two regions of the United States. We employed 15 nuclear simple sequence repeat (SSR) markers and one polymorphic chloroplast marker. Further, we utilized both conventional population genetic metrics along with Shannon diversity indices as the latter have been proposed to be more sensitive to allele frequency changes and differentiation. We found that populations in both regions that were proximal to crop fields showed lower levels of differentiation to the crops than populations that were located farther away. We also found that Shannon measures were more sensitive to differences in both genetic diversity and differentiation in our study. Finally, we found indirect evidence of paternal transmission of chloroplast DNA and accompanying lower than expected levels of chloroplast genetic structure amongst populations as might be expected if chloroplast DNA genes flow through both seed and pollen. Our findings of substantial gene flow for both nuclear and chloroplast markers demonstrate the efficiency of both pollen and seed to transfer genetic information amongst populations of carrot.
... Populations of wild carrots are very common along roadsides, cultivated fields and in early succession wastelands across most of Europe, but the species also occurs in late-successional grasslands. Wild carrots are considered weeds in North America and Japan, where they have been introduced (Hauser et al., 2004;Umehara et al., 2005). ...
In nature so-called ‘biennial’ plants often delay their life cycle, flowering in the third or fourth year, or even later. Life-history theory predicts that high rosette survival is associated with longer life histories. We test this in wild carrot (Daucus carota) populations along disturbed roadsides in the Netherlands, covering a range from unfertile to highly fertile soils. Only 24.2% of the plants behaved as biennial or monocarpic perennial. Most plants were winter (38.9%) or summer annual (36.8%). There was no significant association between life history and habitat, despite differences in mortality and soil fertility between the populations. Annual rosette survival was between 19% and 80%, indicating a high turnover of populations. As predicted by life history theory, the fraction summer annuals (the shortest life-cycle) decreased significantly with rosette survival. In five populations the fraction plants flowering increased with plant size in a similar manner, but in the North Holland dune population plants had a higher threshold size. The annual behaviour of the carrots is quite different from their monocarpic perennial life cycle described in other studies. Carrot cultivars may cross with wild carrots and in this way generation time of the offspring can be affected. We discuss how this may affect plant fitness in the wild.
... They estimated outcrossing rates of 96% for wild carrot populations and explained this high outcrossing rate by the strongly proterandrous inflorescence with stigmas only becoming receptive when anthers of all stamens in the umbel have completed dehiscence (Koul et al. 1989). Thus, the specialized pollination mechanism triggers pollen-mediated gene flow among distant individuals and weakens spatial genetic structures (Umehara et al. 2005;Rong et al. 2010). ...
... The detected slight differences in diversity estimates between indigenous and restored populations could potentially pinpoint to novel genotype introductions in the region, however, from very similar population genetic origin. Umehara et al. (2005) already stated that carrots, even cultivated varieties and wild carrots, have extremely wide gene diversity (Rong et al. 2010). This is supported by our analysis which revealed substantial levels of genetic diversities on different scales, such as (1) within populations, (2) between individuals of the indigenous sites but also on the restored sites, and (3) throughout the investigation area. ...
For restoration purposes, nature conservation generally enforces the use of local seed material based on the "local-is-best" (LIB) approach. However, in some cases recommendations to refrain from this approach have been made. Here we test if a common widespread species with no obvious signs of local adaptation may be a candidate species for abandoning LIB during restoration. Using 10 microsatellite markers we compared population genetic patterns of the generalist species Daucus carota in indigenous and formerly restored sites (nonlocal seed provenances). Gene diversity overall ranged between He = 0.67 and 0.86 and showed no significant differences between the two groups. Hierarchical AMOVA and principal component analysis revealed very high genetic population admixture and negligible differentiation between indigenous and restored sites (FCT = 0.002). Moreover, differentiation between groups was caused by only one outlier population, where inbreeding effects are presumed. We therefore conclude that the introduction of nonlocal seed provenances in the course of landscape restoration did not jeopardize regional species persistence by contributing to inbreeding or outbreeding depressions, or any measurable adverse population genetic effect. On the basis of these results, we see no obvious objections to the current practice to use the 10-fold cheaper, nonlocal seed material of D. carota for restoration projects.
... Niemann et al. (1997) have developed the first set of SSR markers for carrot and later assigned 19 SSR markers to a carrot linkage map (Niemann, 2001). Other sets of SSR markers were described by Umehara et al. (2005) and Clotault et al. (2010). By far more SSR markers became available to anchor new D. carota linkage maps, when Cavagnaro et al. (2011) provided a set of 300 SSR markers for carrot and assigned 55 of them to all nine LGs. ...
A linkage map of carrot (Daucus carota L.) was developed in order to study reproductive traits. The F 2 mapping population derived from an initial cross between a yellow leaf (yel) chlorophyll mutant and a compressed lamina (cola) mutant with unique flower defects of the sporophytic parts of male and female organs. The genetic map has a total length of 781 cM and included 285 loci. The length of the nine linkage groups (LGs) ranged between 65 and 145 cM. All LGs have been anchored to the reference map. The objective of this study was the generation of a well-saturated linkage map of D. carota. Mapping of the cola-locus associated with flower development and fertility was successfully demonstrated. Two MADS-box genes (DcMADS3, DcMADS5) with prominent roles in flowering and reproduction as well as three additional genes (DcAOX2a, DcAOX2b, DcCHS2) with further importance for male reproduction were assigned to different loci that did not co-segregate with the cola-locus.
... Niemann et al. (1997) have developed the first set of SSR markers for carrot and later assigned 19 SSR markers to a carrot linkage map (Niemann, 2001). Other sets of SSR markers were described by Umehara et al. (2005) and Clotault et al. (2010). By far more SSR markers became available to anchor new D. carota linkage maps, when Cavagnaro et al. (2011) provided a set of 300 SSR markers for carrot and assigned 55 of them to all nine LGs. ...
A linkage map of carrot (Daucus carota L.) was developed in order to study reproductive traits. The F2 mapping population derived from an initial cross between a yellow leaf (yel) chlorophyll mutant and a compressed lamina (cola) mutant with unique flower defects of the sporophytic parts of male and female organs. The genetic map has a total length of 781 cM and included 285 loci. The length of the nine linkage groups ranged between 65 cM and 145 cM. All linkage groups have been anchored to the reference map. The objective of this study was the generation of a well-saturated linkage map of D. carota. Mapping of the cola-locus associated with flower development and fertility was successfully demonstrated. Two MADS-
box genes (DcMADS3, DcMADS5) with prominent roles in flowering and reproduction as well as three additional genes (DcAOX2a, DcAOX2b, DcCHS2) with further importance for male reproduction were assigned to different loci that did not co-segregate with the cola-locus.
