Genetic diversity of wild, weedy and cultivated forms of Brassica rapa

Crouch, J. H.; Lewis, B.; Lydiate, Derek J.; Mithen, Richard

doi:10.1038/hdy.1995.69

Cited by 13 publications

(7 citation statements)

References 16 publications

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“…Previous studies, using morphology and RFLP analysis (Sinskaja 1928;Prakash and Hinata 1980;Song et al 1988Song et al , 1990Crouch et al 1995) indicated that ssp. rapa and ssp.…”

Section: Discussionmentioning

confidence: 95%

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Phylogenetic relationships among cultivated types of Brassica rapa L. em. Metzg. as revealed by AFLP analysis

Takuno

Kawahara

Ohnishi

2006

Genet Resour Crop Evol

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The cultivated types of Brassica rapa L. em. Metzg. consist of morphologically distinct subspecies such as turnip, turnip rape, Chinese cabbage, pak choi and pot herb mustard which are classified as ssp. rapa, ssp. oleifera, ssp. pekinensis, ssp. chinensis and ssp. nipposinica (syn. ssp. japonica), respectively. We attempted to elucidate the phylogenetic relationships among the cultivated types of B. rapa. Thirty-two accessions from the Eurasian Continent were analyzed using AFLP markers with a cultivar of B. oleracea as an outgroup. In total, 455 bands were detected in the ingroup and 392 (86.6%) were polymorphic. The Neighbor-Joining tree based on the AFLP markers indicated that the accessions of B. rapa were congregated into two groups according to geographic origin. One group consisted of ssp. rapa and ssp. oleifera of Europe and Central Asia and the other included all the subspecies of East Asia. Our results suggest that cultivars from East Asia were probably derived from a primitive cultivated type, which originated in Europe or in Central Asia and migrated to East Asia. This primitive cultivated type was probably a common ancestor of ssp. rapa and ssp. oleifera. The Neighbor-Joining tree also shows that leafy vegetables in East Asia such as ssp. pekinensis, ssp. chinensis and ssp. nipposinica were differentiated several times from the distinct cultivars of ssp. oleifera in East Asia.

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“…Previous studies, using morphology and RFLP analysis (Sinskaja 1928;Prakash and Hinata 1980;Song et al 1988Song et al , 1990Crouch et al 1995) indicated that ssp. rapa and ssp.…”

Section: Discussionmentioning

confidence: 95%

“…The cultivated type of B. rapa was classified into two major groups based on morphology (Sinskaia 1928;Prakash and Hinata 1980) and restriction fragment length polymorphism (RFLP) markers (Song et al 1988;Crouch et al 1995). One group consists of ssp.…”

Section: Introductionmentioning

confidence: 99%

Phylogenetic relationships among cultivated types of Brassica rapa L. em. Metzg. as revealed by AFLP analysis

Takuno

Kawahara

Ohnishi

2006

Genet Resour Crop Evol

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“…Identification of such populations is important to avoid incorporating them in a gene bank under an erroneous identity. Such misplacements may affect the quality of both breeding and research based on gene bank accessions (Crouch et al 1995). In addition, such misplacements can cause redundant duplications that are generally regarded as wasted capacity and if possible, should be excluded (Van Treuren et al 2004).…”

Section: Population Structurementioning

confidence: 99%

“…; feral B. rapa) on the basis of phenotype alone (our own and breeders experience). The erroneous identification of feral B. rapa plants as 'wild' and their subsequent assimilation into germplasm collections dilutes the useable genetic diversity of the repository and could also lead to underestimation of the genetic divergence between wild and cultivated B. rapa (Crouch et al 1995). Studies of genetic diversity based on DNA markers can address this issue by identifying those wild accessions that are truly genetically divergent from feral escapes and so warrant collection.…”

Section: Introductionmentioning

confidence: 97%

Processes affecting genetic structure and conservation: a case study of wild and cultivated Brassica rapa

Andersen

Poulsen²,

Andersen

et al. 2008

Genet Resour Crop Evol

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Andersen, N. S., Poulsen, G., Andersen, B. A., Kiaer, L. P., D'Hertefeldt, T., Wilkinson, M. J., Jorgensen, R. B. (2009). Processes affecting genetic structure and conservation: a case study of wild and cultivated Brassica rapa. Genetic Resources and Crop Evolution, 56, (2), 189-200. Sponsorship: Nordic Gene Bank (Alnarp, Sweden)/ EU project SIGMEA /SOAR (Research School for Organic Agriculture and Food System). IMPF: 01.24When planning optimal conservation strategies for wild and cultivated types of a plant species, a number of influencing biological and environmental factors should be considered from the outset. In the present study Brassica rapa was used to illustrate this: to develop Scandinavian conservation strategies for wild and cultivated B. rapa, DNA-marker analysis was performed on 15 cultivated and 17 wild accessions of B. rapa plus 8 accessions of the cross compatible B. napus. The B. rapa cultivars were bred in Sweden and Finland in 1944?1997 and the wild B. rapa material was collected from Denmark, Sweden and United Kingdom. The B. napus accessions were bred within the last 20 years in the Scandinavian countries. Results were based on scoring of 131 polymorphic ISSR markers in the total plant material. A Bayesian Markov chain Monte Carlo (MCMC) approach implemented in NewHybrids demonstrated a clear distinction of B. rapa and B. napus individuals except for three individuals that seemed to be backcrosses. The backcrossed hybrids descended from two Swedish populations, one wild and one escaped. The overall pattern of genetic variation and structure in B. rapa showed that cultivated and wild B. rapa accessions formed two almost separated clusters. Geographical origin and breeding history of cultivars were reflected in these genetic relationships. In addition, wild populations from Denmark and Sweden seemed to be closely related, except for a Swedish population, which seemingly was an escaped cultivar. The study point to that many processes, e.g. spontaneous introgression, naturalisation, breeding and agricultural practise affected the genetic structure of wild and cultivated B. rapa populations.Peer reviewe

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“…In some weed species, such studies have helped to improve our understanding of: (i) the taxonomic relationships between cultivated and weedy forms (e.g. Crouch et al . 1995); (ii) genetic variation (e.g.…”

Section: Introductionmentioning

confidence: 99%

Microsatellite analysis of the inbreeding grass weed Barren Brome (Anisantha sterilis) reveals genetic diversity at the within‐ and between‐farm scales

et al. 2001

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Nine microsatellites were used to screen 131 samples of Barren Brome (Anisantha sterilis: synonym Bromus sterilis) collected from within the fields of three English farms [from Oxfordshire (Oxon), Leicestershire (Leics) and Wiltshire (Wilts)] and eight seeds taken from samples of each of 10 farms across England, UK. Most individuals (approximately 97%) were homozygous. Polymorphism occurred at all nine loci in all three farms sampled at the field scale, and at most loci for nine of the other 10 farm samples. Between three and 11 alleles were found per locus. Gene diversity (D = 1 - summation operator p(i)2) ranged from 0.088 to 0.760. Polymorphism occurred among individuals within and among fields, and farms. Some alleles were found in only one farm. On the basis of the alleles at all nine loci in the 211 sampled plants, a total of 92 (44%) different genotypes was identified. Clustering analysis using the unweighted pair group method with arithmetic averages (UPGMA) for the combined Oxon, Wilts and Leics samples did not cluster them into their respective farms. Similarly, a phenogram of samples from all 10 farms showed considerable mixing of individuals with respect to farm origins. Identification of genotypes on field plans showed evidence of both spatial localization and mixing. Previous reports have suggested that A. sterilis is strictly inbreeding with little intrapopulation variation at the genetic level. Our data reveal that A. sterilis exists as numerous separate and genetically different lines, which are maintained by inbreeding but which very occasionally outcross. Possible explanations for this pattern of high genetic diversity are discussed.

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Genetic diversity of wild, weedy and cultivated forms of Brassica rapa

Cited by 13 publications

References 16 publications

Phylogenetic relationships among cultivated types of Brassica rapa L. em. Metzg. as revealed by AFLP analysis

Phylogenetic relationships among cultivated types of Brassica rapa L. em. Metzg. as revealed by AFLP analysis

Processes affecting genetic structure and conservation: a case study of wild and cultivated Brassica rapa

Microsatellite analysis of the inbreeding grass weed Barren Brome (Anisantha sterilis) reveals genetic diversity at the within‐ and between‐farm scales

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