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1.
João S. Dias 《Genetic Resources and Crop Evolution》1995,42(4):363-369
Nuclear RFLPs were used to study the genetic relationships of 2 Portuguese coles, tronchuda cabbage and Galega kale, and 13
otherBrassica oleracea cultivars and 4 nine-chromosome wild brassicas. Cluster and principal coordinates analysis were conducted using RFLP data
from 60 probe-enzyme combinations, detecting 277 polymorphic restriction fragments. The results showed that the accessions
clustered in five groups: one with all theB. oleracea cultivars except kailan, and the four others isolated with kailan, wildB. oleracea, B. insularis andB. cretica, andB. montana, respectively. Kailan was separated from the other accessions ofB. oleracea cultivars and genetically close to the wildB. oleracea, that was clearly separated from the other nine-chromosome wild brassicas. In theB. oleracea cultivars 3 groupings were clearly individualized: i) including broccolis and cauliflower; ii) with a misture of kales and
cabbages originally from Central-North Europe; iii) formed by Portuguese coles. These preliminary results suggest the existence
of three major regions of domestication of B. oleracea in Europe: Italy, Central-North Europe and Portugal. Kailan or chinese
kale seems to have evolved separately from the otherB. oleracea cultivars in Eastern Asia. 相似文献
2.
Naja Steen Andersen Gert Poulsen Bente Anni Andersen Lars Pødenphant Kiær Tina D’Hertefeldt Mike J. Wilkinson Rikke Bagger Jørgensen 《Genetic Resources and Crop Evolution》2009,56(2):189-200
When 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. 相似文献
3.
As an oilseed crop, the cultivation of Ethiopian mustard (Brassica carinata) is restricted only to Ethiopia. Even though geographic diversity is a potent source of allelic diversity, the extent of genetic diversity among germplasm material of Ethiopian mustard from different countries has not been assessed. Forty-three accessions, comprising 29 accessions from eight different geographic regions of Ethiopia and 14 exotic accessions from Australia, Pakistan, Spain, and Zambia were analysed for their genetic diversity using random amplified polymorphic DNA (RAPD) technique. A set of 50 primers yielded a total of 275 polymorphic bands allowing an unequivocal separation of every Ethiopian mustard accession. The usefulness of the 50 RAPD primers in measuring heterozygousity and distinguishing accessions was variable such that polymorphic information content (PIC) varied from 0.05 to 0.40, band informativeness (BI) from 0.05 to 0.65 and primer resolving power (RP) from 0.15 to 6.83. Jaccard's similarity coefficients ranged from 0.44 to 0.87 indicating the presence of a high level of genetic diversity. On the average, Australian and Ethiopian accessions were the most similar while, Spanish and Zambian accessions were the most distant ones. Cluster analysis grouped the 43 accessions into four groups, which has quite a high fit (r = 0.80) to the original similarity matrix. With no prior molecular information, the RAPD technique detected large genetic diversity among the 43 accessions from five different countries and their grouping by dendrogram and principal coordinate analysis (PCoA) was inclined towards geographic differentiation of RAPD markers. Conversely, RAPD differentiation along geographic origin was not apparent within the Ethiopian accessions. 相似文献
4.
M. Hasan F. Seyis A. G. Badani J. Pons-Kühnemann W. Friedt W. Lühs R. J. Snowdon 《Genetic Resources and Crop Evolution》2006,53(4):793-802
Genetic diversity throughout the rapeseed (Brassica napus ssp. napus) primary gene pool was examined by obtaining detailed molecular genetic information at simple sequence repeat (SSR) loci
for a broad range of winter and spring oilseed, fodder and leaf rape gene bank accessions. The plant material investigated
was selected from a preliminary B. napus core collection developed from European gene bank material, and was intended to cover as broadly as possible the diversity
present in the species, excluding swedes (B. napus ssp. napobrassica (L.) Hanelt). A set of 96 genotypes was characterised using publicly available mapped SSR markers spread over the B. napus genome. Allelic information from 30 SSR primer combinations amplifying 220 alleles at 51 polymorphic loci provided unique
genetic fingerprints for all genotypes. UPGMA clustering enabled identification of four general groups with increasing genetic
diversity as follows (1) spring oilseed and fodder; (2) winter oilseed; (3) winter fodder; (4) vegetable genotypes. The most
extreme allelic variation was observed in a spring kale from the United Kingdom and a Japanese spring vegetable genotype,
and two winter rape accessions from Korea and Japan, respectively. Unexpectedly the next most distinct genotypes were two
old winter oilseed varieties from Germany and Ukraine, respectively. A number of other accessions were also found to be genetically
distinct from the other material of the same type. The molecular genetic information gained enables the identification of
untapped genetic variability for rapeseed breeding and is potentially interesting with respect to increasing heterosis in
oilseed rape hybrids. 相似文献
5.
Perennial kale is a rare leafy vegetable and forage crop that is mainly vegetatively propagated and therefore expensive to
conserve ex situ. A genebank collection of 47 perennial kales and 34 reference samples from the main Brassica oleracea crop types were characterized with seven microsatellite markers in order to verify potential redundancies and to obtain more
insight in the position of perennial kales within B. oleracea. Based on the obtained results and on data from previous studies, the collection was reduced with 49% to 24 perennial kales.
Considering this level of reduction, it was estimated that the investments made for the final verification by microsatellite
analysis are returned after only 4-year time. A principal coordinate plot clearly separated the perennial kales from the other
crop types of B. oleracea, except in one case. This deviating accession of vegetatively preserved perennial kale clustered closely together with the
single seed-preserved accession of perennial kale included in the study. These two accessions occupied an intermediate position
between the group of vegetatively propagated perennial kales and the group of seed-propagated Brassica accessions, suggesting a hybridization background with another B. oleracea crop type. The microsatellite study demonstrated a close genetic relationship among the investigated perennial kales and
their unique position within B. oleracea. 相似文献
6.
Warren F. Lamboy James R. McFerson Anne L. Westman Stephen Kresovich 《Genetic Resources and Crop Evolution》1994,41(2):99-108
Summary Management of a genetic resources collection is more effective if a curator can accurately identify genotypes and accessions as well as assess intraspecific genetic relationships and the genetic structure of species. Consequently, a study was conducted to determine whether data from starch gel electrophoresis of a specific set of isozymes from plants of Brassica oleracea (cole crops) would be useful in answering four questions the answers to which are essential for effective curatorial activities: Can individual plants be identified? Can specific accessions be identified? What are the genetic relationships among botanical varieties within B. oleracea? What is the genetic structure of the species B. oleracea? Six loci from 4 enzyme systems (LAP, PGD, PGI, and PGM) were analyzed. Individuals and accessions could not usefully be identified using these isozymes, but genetic relationships within and genetic structure of the species were easily determined, resulting in specific recommendations for improving collection management. As expected, highly selected commercial lines exhibited less diversity than average, and so may be of limited value when trying to maximize diversity with a minimum number of accessions. In contrast, landraces and weakly selected lines are more diverse than average, and thus are useful in maximizing per accession diversity. Not only was 93% of the genetic variability in B. oleracea found among accessions and a mere 7% among varieties, but also a cluster analysis showed that accessions of a single botanical variety are often more similar to those of a different variety than to each other. These results suggest that in order to create a genetic resources collection of B. oleracea that faithfully represents the diversity in the species, a curator should assemble a broad array of accessions originating from diverse agroecological niches, having different levels of improvement, and representing all botanical varieties.Abbreviations LAP
Leucine amino peptidase
- PGD
6-Phosphogluconate dehydrogenase
- PGI
Phosphoglucoisomerase
- PGM
Phosphoglucomutase
- RAPD
Random amplified polymorphic DNA
- RFLP
Restriction fragment length polymorphism
- UPGMA
Unweighted pair-group method using arithmetic averages 相似文献
7.
K. Persson R. von Bothmer M. Gullord E. Gunnarsson 《Genetic Resources and Crop Evolution》2006,53(4):857-866
Phenotypic diversity for agronomic characteristics was determined in an experiment with 29 landraces and 14 improved varieties
of rye from the Nordic area, Germany and Poland. The accessions were scored for 12 characters. Effects of the location, year,
type, and country of origin for landraces were investigated with analysis of variance. Phenotypic variations for the traits
were estimated using the Shannon–Weaver diversity index. The genetic variation was high, with an average of H 0 = 0.566. The landraces from Norway, Sweden and Finland showed the highest variation, whereas the improved varieties had the
lowest. The German material also had low variation but the status of this material is uncertain. The genetic diversity showed
that 70% of the variation was found within the accessions. A cluster analysis was carried out to identify the relationship
between the accessions. The material grouped into eight clusters, where clusters I to V included landraces from Sweden, Finland
and Norway, except for cluster III, which included one improved variety from Denmark. Cluster VI comprised a single Swedish
landrace from Gotland. Most of the improved varieties were in cluster VII and the last cluster contained accessions from Germany
and Sweden. 相似文献
8.
Roland von Bothmer Mats Gustafsson Sven Snogerup 《Genetic Resources and Crop Evolution》1995,42(2):165-178
Summary An extensive crossing program including 10 wild taxa and 23 accessions representing 6 major cultivated forms and landraces
of theBrassica oleracea group was carried out. Data for crossability, germination, viability, fertility inF
1 andF
2 were studied as well as the meiotic chromosomal pairing inF
1 hybrids in some combinations. The fertility of hybrids between all cultivated forms and wild populations ofB. oleracea was high and it was concluded that all, including the Chinese endemicalboglabra form, belong to the same biological species. Among the other species,B. macrocarpa, B. montana, andB. rupestris had the lowest andB. cretica the highest fertility values in crosses with cultivated forms. The crossing data do not give any further information as to
the genetic differentiation ofB. oleracea during the course of domestication. Introgression between wild and cultivated forms has probably occurred frequently. All
members of theB. oleracea cytodeme belong to the primary and secondary gene pools of the 18 chromosomic crops and are as such of great importance for
breeding purposes. 相似文献
9.
Amplified fragment length polymorphism (AFLP) analysis was used to evaluate the genetic relationships and diversities of Chinese
vegetable mustards. Fourteen pairs of primers generated a total of 366 scorable fragments among 16 accessions of Brassica juncea studied, of which 296 bands were polymorphic with an average of 21.1% polymorphic bands per primer combination. Genetic similarities
were obtained using Nei and Li similarity coefficients, and a dendrogram of the 16 accessions was made by UPGMA clustering
method. The Nei and Li Similarity coefficient value ranged from 0.63 to 0.88. This result indicated that the 16 accessions
of B. juncea possessed high level genetic variations. The cluster analysis showed that the vegetable mustards could be grouped into two
main groups and some minor rami, which was partially in accordance with the traditional classification that based on different
edible organs of vegetable mustards. The incongruity between morphological and molecular classification might be attributed
to the high selection pressure during domestication of Chinese vegetable mustards, producing some accessions with similar
genetic backgrounds evolving into abundant morphological variations. The great diversification among Chinese vegetable mustards
not only provides an excellent object for molecular evolution research of B. juncea but also is of great value for widening the genetic basis of breeding programs and breeding materials selection. Besides,
our study also indicates that AFLP are informative and can provide significant insights for genetic diversity research in
B. juncea. 相似文献
10.
X. K. Zhang J. Chen L. Chen H. Z. Wang J. N. Li 《Genetic Resources and Crop Evolution》2008,55(8):1175-1184
In this study, the correlations among these characters were investigated in 18 rapeseed (Brassica napus L.) accessions with different seed coat color. The results indicated that seed water uptake and flooding tolerance were significantly
correlated with seed color and melanin pigment content of testa. The red or black-seeded accessions had higher melanin content
in testa, showed slower water uptake and lower leakage and higher flooding tolerance. The majority of yellow-seeded rapeseed
accessions which had low melanin pigments content in testa showed a rapid water uptake and higher leakage than the red or
black-seeded, which led to imbibition damage and lower flooding tolerance. The results suggest that the yellow-seeded cultivars
experienced poor field emergence and more serious pre-harvest sprouting in raining weather than the dark-seeded cultivars.
Some yellow-seeded accessions showed a slow imbibition behavior and relative high flooding tolerance, indicated these accessions
can be used as a genetic resource to improve the flooding tolerance and reduce imbibition damage for the yellow-seeded B. napus L. 相似文献
11.
Total 65 lotus accessions in genus Nelumbo mainly collected from China, were subjected to random amplified polymorphic DNA (RAPD) markers to estimate the genetic diversity
and to test the genetic basis of the relationships between morphotypes and molecular markers. Seventeen primers generated
a total of 195 highly reproducible and discernible loci, among which 173 were polymorphic. Percent polymorphism varied from
66.7 to 100 with an average of 88.72, and five primers out of them, OPC05, OPG10, OPN20, OPP09 and OPS17, showed 100% polymorphism.
A relatively high genetic diversity was detected among all the samples with the similarity coefficient values ranging from
0.45 to 0.85, and Nei’s gene diversity (h) 0.30, and Shannon index (I) 0.46. The UPGMA dendrogram clustered 65 accessions in four clusters and the clustering pattern showed two groups, N. nucifera ssp. nucifera and those accessions related to the American lotus, and some special cultivars, landraces, hybrids and the American lotus.
Principal Coordinate Analysis (PCA) further indicated that the genetic diversity of Nelumbo accessions was not evenly distributed, instead, was presented by a clustered distribution pattern. Similar to the results
revealed by the dendrogram, two main groups representing the two subspecies of N. nucifera, as well as some special landraces, cultivars of Chinese lotus, the Japanese lotus and hybrids out of the two groups were
obtained. Neither the UPGMA dendrogram nor the PCA analysis exhibited strict relationship with geographic distribution and
morphotypes among the accessions. 相似文献
12.
Shohei Takuno Taihachi Kawahara Ohmi Ohnishi 《Genetic Resources and Crop Evolution》2007,54(2):279-285
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. 相似文献
13.
M. W. Farnham E. H. Davis J. T. Morgan J. P. Smith 《Genetic Resources and Crop Evolution》2008,55(6):797-801
A common garden crop grown in the coastal plain region of North and South Carolina (United States) is the non-heading, leafy
green type of Brassica oleracea L. known as collard (B. oleracea L. subsp. oleracea convar. acephala (DC.) Alef. var. viridis L.). Predominantly a fall and winter vegetable in this region, collard is often the only green planting to be found in the
yard or garden of a rural home during these cool seasons. Historically, the traditional collard patch and even commercial
fields were planted with unique varieties perpetuated by individual seed savers, and collectively, the regional diversity
for this crop was probably very significant for well over a century. Genetic erosion of this collard germplasm pool has been
severe in recent decades as commercial hybrids have been adopted by both large-scale producers and home gardeners. Although
a significant number of collard landraces are being perpetuated to this day, existing diversity among landraces still grown
in the region is now in the hands of an aging population of seed savers who maintain germplasm through on-farm preservation.
From 2003 to 2006, we explored the coastal plain region of North and South Carolina in search of collard gardens containing
traditional landraces. Exploration trips were conducted mid-winter to early spring. About 90 samples of collard were obtained
from seed savers during the course of this exploration. Observations of morphological differences of these landraces indicate
that significant diversity exists in this group. Obtained landraces are being deposited into the U.S. plant introduction collection
and will be available for future use. This preserved collection could prove to be an important new source of genes for B. oleracea improvement. 相似文献
14.
Summary Karyotypic differences among n = 9 Brassica species, as well as the inheritance of some morphological characteristics, are reported. Annual habit, anthocyanin pigmentation in leaf and stem, enlarged stem, glossy foliage, dark green foliage, white flower and leaf pubescence were all expressed as dominant characteristics and in most cases were determined by one or two genes. 172 intra- and interspecific hybrids of the species belonging to the Brassica oleracea cytodeme were analyzed for fertility and meiotic chromosome behavior. B. alboglabra, B. bourgeaui, B. cretica spp. cretica, B. montana and B. oleracea produced fertile interspecific hybrids, indicating that geographical isolation is the only barrier to gene exchange. Interspecific hybrids generated from crosses of B. incana, B. insularis and B. rupestris to other n = 9 species were semi-sterile. This was shown to be associated with abnormal meiotic behavior. The former two species, when crossed, produced fully fertile hybrids. Therefore, three different karyotypes are identified among the n = 9 Brassica species. Frequent changes in the genome of the species belonging to the Brassica oleracea cytodeme could have led to the formation of accessory chromosomes present in certain accessions. 相似文献
15.
Ilknur Solmaz Nebahat Sari Yildiz Aka-Kacar N. Yesim Yalcin-Mendi 《Genetic Resources and Crop Evolution》2010,57(5):763-771
Genetic diversity of the Turkish watermelon genetic resources was evaluated using different Citrullus species, wild relatives, foreign landraces, open pollinated (OP) and commercial hybrid cultivars by RAPD markers. The germplasm
was consisted of 303 accessions collected from various geographical regions. Twenty-two of 35 RAPD primers generated a total
of 241 reproducible bands, 146 (60.6%) of which were polymorphic. Based on the RAPD data the genetic similarity coefficients
were calculated and the dendrogram was constructed using UPGMA (Unweighted pair-group method with arithmetic average). Cluster
analysis of the 303 accessions employing RAPD data resulted in a multi-branched dendrogram indicating that most of the Turkish
accessions belonging to var. lanatus of Citrullus lanatus (Thunb.) Matsum et Nakai were grouped together. Accessions of different Citrullus species and Praecitrullus fistulosus (Stocks) Pangalo formed distant clusters from C. lanatus var. lanatus. Among 303 accessions, a subset of 56 accessions was selected representing different groups and a second dendrogram was constructed.
The genetic similarity coefficients (GS) within the Turkish accessions were ranged from 0.76 to 1.00 with 0.94 average indicating
that they are closely related. Taken together, our results indicated that low genetic variability exist among the watermelon
genetic resources collected from Turkey contrary to their remarkable phenotypic diversity. 相似文献
16.
Xiao-Hua Qi Ming-Fang Zhang Jing-Hua Yang 《Genetic Resources and Crop Evolution》2007,54(8):1709-1716
Sequence variation of nuclear internal transcribed spacer regions of ribosomal DNA (ITS1, 5.8S rRNA and ITS2) from Chinese
vegetable mustards (AB-genome) and its putative parents Brassica rapa (the A-genome) and Brassica nigra (the B-genome) were used to investigate the molecular phylogeny and the probable evolutional pattern of this amphidiploid
species that uniquely formed in China. Totally, 16 accessions of Chinese vegetable mustard those covering nearly all the diverse
variations were included in this study, and together with three accessions of B. rapa and one accession of B. nigra. The results disclosed two strongly supported clades, one containing four accessions of vegetable mustard which have closer
relationship with B-genome species “B.nigra” lineage and the other containing 12 accessions of B. juncea and three A-genome accessions. This classification was in disagreement with the evidence from chloroplast DNA, mitochondrial
DNA, nuclear DNA restriction fragment length polymorphism (RFLP), which suggested that B. juncea was closely related to the A-genome type. For the incongruence, we speculated that the B. juncea crops derived from Chinese have evolved through different recombined events of the diploid morphutypes and evolved unidirectional
concerted evolution. The traditional phenotypic classification of B. juncea was not wholly supported by ITS results, and hence the phylogenetic relationships among these subspecies need to be reconsidered
on molecular level. 相似文献
17.
B. Kalyana Babu N. Senthil S. Michael Gomez K. R. Biji N. S. Rajendraprasad S. Satheesh Kumar R. Chandra Babu 《Genetic Resources and Crop Evolution》2007,54(2):399-404
Finger millet (Eleusine coracana), an allotetraploid cereal, is widely cultivated in the arid and semiarid regions of the world. Being rich in protein and
calcium, finger millet serves as an important staple food for rural populations in developing tropical countries where calcium
deficiency and anemia are wide spread. Thirty-two finger millet genotypes were fingerprinted using 50 random amplified polymorphic
DNA (RAPD) markers. Out of the total 529 loci generated using the 50 RAPD primers, 479 loci (91%) were polymorphic and informative
to differentiate the accessions. Cluster analysis grouped the 32 finger millet accessions into two major clusters. Among the
32 finger millet genotypes, GEC 182 and CO 12 were distantly related with a low similarity index of 0.315. These two accessions
also differed considerably in days to flowering and grain weight; GEC 182 is early flowering and has bold grains, while CO
12 is late flowering and has smaller grains. These two accessions with higher diversity at molecular level, phenology and
grain weight will be ideal as parents in hybridization programme, to develop improved finger millet varieties suitable for
peninsular region of India. 相似文献
18.
Simona Ciancaleoni Giuseppina Laura Chiarenza Lorenzo Raggi Ferdinando Branca Valeria Negri 《Genetic Resources and Crop Evolution》2014,61(2):451-464
Brassica oleracea L. is an important species that originated in the eastern Mediterranean area. From there, B. oleracea L. subsp. capitata (L.) DC. convar. botrytis (L.) Alef. var. italica Plenck (broccoli) was introduced into Italy where considerable diversification took place. Several landraces of broccoli, which are highly appreciated by local people for their organoleptic traits, are presently cultivated in both large fields and home gardens. In this study, 10 landraces, 4 synthetics derived from landraces and 4 of the most used F1 hybrids were characterised for morpho-physiological and molecular traits with the principal aim of feeding information into the landrace protection schemes being developed in Italy and into breeding programs. The landraces and derived synthetics are well differentiated from each other and from the F1 hybrids for important agronomic and genetic traits. The principal component analysis based on analysis of morpho-physiological traits showed that overall the 2 main components accounted for 67.74 % of the total variation. The neighbour joining tree, based on 23 microsatellite markers, grouped accessions into 2 main clusters. One includes one synthetic variety and 2 F1 hybrids, while the other cluster includes all the other accessions. There were also several sub clusters. Most of the materials examined showed within-accession diversity. The information gathered in this study can be used to protect landraces through the schemes presently being developed in Italy and to register them in the European common catalogue of “conservation varieties”. In situ (on-farm) conservation of landrace diversity is discussed with reference to landrace use. 相似文献
19.
Yasuyuki Morimoto Patrick Maundu Makoto Kawase Hiroshi Fujimaki Hiroko Morishima 《Genetic Resources and Crop Evolution》2006,53(5):963-974
The present study was performed to investigate genetic diversity of Kenyan landraces of the white-flowered gourd (Lagenaria siceraria), which exhibits tremendous morphological variation. RAPD analyses were performed on 53 landraces of the cultivated species
L. siceraria and 42 accessions of three wild species (40 L. sphaerica, 1 L. abyssinica, and 1 L. breviflora). A total of 432 polymorphic bands were detected using 54 primers. The four species were clearly differentiated from one
another. Intra-specific variations were investigated with L. siceraria and its wild relative L. sphaerica. Landraces of the cultivated species collected from different ethnic communities or regions were differentiated. Morphological
variations were not associated with RAPD variations. Bitter landraces collected in Maasai communities showed two specific
RAPD bands. In the wild species, accessions collected from the eastern and western sides of the Great Rift Valley were genetically
differentiated from each other. In both species, genetic and geographical distance matrices computed among all pairs of accessions
were significantly correlated, implying that the observed geographical variation can be explained by the 'Isolation by distance
model'. Progeny plants derived from a common mother in L. siceraria showed a low level of segregation in RAPD pattern, suggesting that collected landraces are cultivated, maintaining their
inherent traits although they are monoecious and insect-pollinated, whereas the wild relative L. sphaerica showed a higher level of segregation. The morphological diversity observed among landraces of L. siceraria is the result of human selection and their genetic identities are maintained by inbreeding probably resulting from frequent
self-pollination. 相似文献
20.
S. Louarn A. M. Torp I. B. Holme S. B. Andersen B. D. Jensen 《Genetic Resources and Crop Evolution》2007,54(8):1717-1725
Fifty-nine Brassica oleracea cultivars, belonging to five botanical varieties, were evaluated for microsatellite (SSR) polymorphisms using 11 database
sequence derived primer pairs. The cultivars represented 12 broccoli (Brassica oleracea var. italica), ten Brussels sprouts (B. o. var. gemmifera), 21 cabbage (B. o. var. capitata, including the groups white and red cabbage), six savoy cabbage (B. o. var. sabauda), and ten cauliflower (B. o. var. botrytis) cultivars from 13 seed suppliers. The 11 primer pairs amplified in total 47 fragments, and differentiated 51 of the cultivars,
whereas the remaining eight cultivars were differentiated from the rest in four inseparable pairs. All SSR markers, except
one, produced a polymorphic information content (PIC value) of 0.5 or above. The average diversity for all markers within
the tested material was 0.64. There was no major difference in the diversity within botanical varieties and groups. The cluster
analysis and the resulting dendrogram showed that the cultivars tended to group within these taxonomic units. The present
study substantiates the use of microsatellite markers as a powerful tool for cultivar differentiation and identification in
vegetable brassicas. 相似文献