Allozyme variation in domesticated annual sunflower and its wild relatives

Cronn, Richard; Brothers, M. E.; Klier, K.; Bretting, P. K.; Wendel, Jonathan F.

doi:10.1007/s001220050594

Cited by 50 publications

(38 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eight of these systems were screened in this study, revealing nineteen loci, eight of which were polymorphic. The observed values of P (0.42), A (1.47) and Ap (2.125) were very similar to those reported by Cronn et al (1997), who studied isozyme polymorphism in 700 plants from both oilseed and confectionary sunflower accessions. Except for Mdh-3, the loci that were found to be monomorphic in the 25 elite inbred lines had previously also been found to be monomorphic in cultivated sunflower germplasm (Carrera andPoverene, 1991, 1995;Quillet et al, 1992).…”

Section: Genetic Variation At Sunflower Isozyme Locisupporting

confidence: 88%

“…This narrow sampling of germplasm (would) could reduce the level of polymorphism at the isozyme loci studied. One allelic form was found to predominate at each isozyme locus (Table II), as reported by Cronn et al (1997) in a much larger germplasm survey. This is reflected by the low PI values for each isozyme marker (Table II), which made it necessary to use a number of different F 2:3 populations, in order to map as many loci as possible (Table III).…”

Section: Comparison Between Isozyme and Rflp Markers In Sunflowersupporting

confidence: 69%

“…The following 15 isozyme systems have been reported to reveal useful polymorphism in cultivated sunflower germplasm: aconitase (ACO), acid phosphatase (ACP), alcohol dehydrogenase (ADH), esterase (EST), glutamate dehydrogenase (GDH), glutamate oxaloacetate transaminase (GOT), isocitrate dehydrogenase (IDH), leucine aminopeptidase (LAP), malate dehydrogenase (MDH), malic enzyme (ME), peroxidase (PRX), phosphogluconate dehydrogenase (PGD), phosphoglucoisomerase (PGI), phosphoglucomutase (PGM) and shikimate dehydrogenase (SKDH) (Lay et al, 1988;Quillet et al, 1992;Tersac et al, 1994;Cronn et al, 1997;Mestries et al, 1998). Eight of these systems were screened in this study, revealing nineteen loci, eight of which were polymorphic.…”

Section: Genetic Variation At Sunflower Isozyme Locimentioning

confidence: 99%

“…Isozymes have been used to assess genetic variation in both domesticated and wild sunflower populations (Dry and Burdon, 1986;Rieseberg et al, 1990;Cronn et al, 1997), as well as to establish phylogenetic relationships and speciation mechanisms within the genus Helianthus (Rieseberg et al, 1991;. They have also been used to study intra specific variation in both wild (Carrera and Poverene, 1995;Carrera et al, 1996) and cultivated sunflowers (Carrera and Poverene, 1991;Quillet et al, 1992), as well as to identify interspecific hybrids (Carrera et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Variability among inbred lines and RFLP mapping of sunflower isozymes

et al. 2002

View full text Add to dashboard Cite

Eight isozyme systems were used in this study: acid phosphatase (ACP), alcohol dehydrogenase (ADH), esterase (EST), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), phosphoglucoisomerase (PGI), 6-phosphogluconate dehydrogenase (PGD), and phosphoglucomutase (PGM). The polymorphism of these enzyme systems was studied in 25 elite inbred lines. A total of 19 loci were identified, but only eight of them were polymorphic in the germplasm tested. The polymorphic index for the eight informative markers ranged from 0.08 to 0.57, with a mean value of 0.36. Five isozyme loci were mapped in F 2:3 populations with existing RFLP data. Est-1, Gdh-2 and Pgi-2 were mapped to linkage groups 3, 14 and 9, respectively. As in previous reports, an ACP locus and a PGD locus were found to be linked, both located in linkage group 2 of the public sunflower map.

show abstract

Section: Genetic Variation At Sunflower Isozyme Locisupporting

confidence: 88%

Section: Comparison Between Isozyme and Rflp Markers In Sunflowersupporting

confidence: 69%

Section: Genetic Variation At Sunflower Isozyme Locimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Variability among inbred lines and RFLP mapping of sunflower isozymes

et al. 2002

View full text Add to dashboard Cite

show abstract

“…Rather, analyses of genetic diversity in sunflower have thus far relied primarily on techniques such as allozyme (Rieseberg and Seiler 1990;Cronn et al 1997) and SSR (Tang and Knapp 2003;Harter et al 2004;Burke et al 2005) genotyping. Here we seek to rectify this situation by reporting on patterns of nucleotide polymorphism in a widespread sample of wild sunflower individuals, as well as a diverse collection of cultivars.…”

mentioning

confidence: 99%

Patterns of Nucleotide Diversity in Wild and Cultivated Sunflower

2006

View full text Add to dashboard Cite

Interest in the level and organization of nucleotide diversity in domesticated plant lineages has recently been motivated by the potential for using association-based mapping techniques as a means for identifying the genes underlying complex traits. To date, however, such data have been available only for a relatively small number of well-characterized plant taxa. Here we provide the first detailed description of patterns of nucleotide polymorphism in wild and cultivated sunflower (Helianthus annuus), using sequence data from nine nuclear genes. The resuflts of this study indicate that wild sunflower harbors at least as much nucleotide diversity as has been reported in other wild plant taxa, with randomly selected sequence pairs being expected to differ at 1 of every 70 bp. In contrast, cultivated sunflower has retained only 40-50% of the diversity present in the wild. Consistent with this dramatic reduction in polymorphism, a phylogenetic analysis of our data revealed that the cultivars form a monophyletic clade, adding to the growing body of evidence that sunflower is the product of a single domestication. Eight of the nine loci surveyed appeared to be evolving primarily under purifying selection, while the remaining locus may have been the subject of positive selection. Linkage disequilibrium (LD) decayed very rapidly in the self-incompatible wild sunflower, with the expected LD falling to negligible levels within 200 bp. The cultivars, on the other hand, exhibited somewhat higher levels of LD, with nonrandom associations persisting up to 1100 bp. Taken together, these results suggest that association-based approaches will provide a high degree of resolution for the mapping of functional variation in sunflower.T HE domestication of crop plants is typically accompanied by a genomewide loss of genetic diversity (Tanksley and McCouch 1997). This reduction in diversity is typically due, at least in part, to the population bottleneck that occurs during the founding of a new crop lineage (e.g., Eyre-Walker et al. 1998). In addition to this so-called ''domestication bottleneck,'' the transition to self-fertilization that often accompanies domestication can further reduce levels of genetic diversity (Pollack 1987;Nordborg 2000), as can selection on the genes underlying agronomically important traits (although this latter effect occurs in a locusspecific fashion; e.g., Hanson et al. 1996;Tenaillon et al. 2004). While the effects of domestication on genetic diversity are likely to vary across taxa, comprehensive surveys of nucleotide diversity in crop plants and their wild progenitors have been performed in only a handful of systems. On the basis of data from the major cereal crops, it appears that genomewide reductions in diversity on the order of 30-40% are not uncommon (Buckler et al. 2001), with selectively important loci often exhibiting even greater losses (e.g., Whitt et al. 2002). In addition to these effects on the overall level of polymorphism, domestication can also have a major impact on the organiz...

show abstract

Isozyme Variation in Wild and Cultivated Species of the Genus Trifolium L. (Leguminosae)

Lange¹,

Schifino-Wittmann²

2000

Annals of Botany

View full text Add to dashboard Cite

Allozyme variation in domesticated annual sunflower and its wild relatives

Cited by 50 publications

References 32 publications

Variability among inbred lines and RFLP mapping of sunflower isozymes

Variability among inbred lines and RFLP mapping of sunflower isozymes

Patterns of Nucleotide Diversity in Wild and Cultivated Sunflower

Isozyme Variation in Wild and Cultivated Species of the Genus Trifolium L. (Leguminosae)

Contact Info

Product

Resources

About