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1.
Endashaw Bekele Mulatu Geleta Kifle Dagne Abigail L. Jones Ian Barnes Neil Bradman Mark G. Thomas 《Genetic Resources and Crop Evolution》2007,54(7):1419-1427
Complete sequences for the internal transcribed spacers of the 18s–26s nuclear ribosomal DNA were generated to establish phylogenetic
relationships among five species of the genus Guizotia. Parsimony analysis and pairwise distance data produced a single tree with four clearly distinguished clades that accord
with previously reported chromosomal data. The clades produced here have been discussed with reference to existing taxonomic
treatments. It appears that Guizotia scabra ssp. scabra, G. scabra ssp. schimperi and Guizotia villosa have contributed to the origin of Guizotia abyssinica, the cultivated species of the genus. The present composition of the species of genus Guizotia and the subtribe the genus presently placed in are suggested to be redefined. 相似文献
2.
Milene Silvestrini Michele G. Junqueira Andréa C. Favarin Oliveiro Guerreiro-Filho Mirian P. Maluf Maria B. Silvarolla Carlos A. Colombo 《Genetic Resources and Crop Evolution》2007,54(6):1367-1379
Genetic diversity among 115 coffee accessions from the Coffea Germplasm Collection of IAC was assessed using SSR markers. The germplasm represents 73 accessions of Coffea arabica derived from spontaneous and subspontaneous plants in Ethiopia and Eritrea, species center of origin and diversity, 13 commercial
cultivars of C. arabica developed by the Breeding Program of IAC, 1 accession of C. arabica cv. ‘Geisha’, 13 accessions of C. arabica from Yemen, 5 accessions of C. eugenioides, 4 accessions of C. racemosa and 6 accessions of C. canephora. Genetic analysis was performed using average number of alleles per locus (A), proportion of polymorphic loci (P), Shannon’s genetic index (H′ and G′ST) and clustering analysis. All evaluated species were distinguished by a cluster analysis based on Jaccard’s coefficient.
Differentiation between the cultivated plants of C. arabica and accessions derived from spontaneous and subspontaneous plants was observed. Spontaneous and subspontaneous accessions
from Ethiopia were separated according to the geographical origin: east and west of the Great Rift Valley. Cultivated plants
showed a low genetic diversity with a division in two groups: accessions from Yemen (H′=0,028) and Brazilian commercial cultivars (H′=0,030). The results agreed with previously reported narrow genetic basis of cultivated plants of C. arabica and supported the hypotheses about domestication of the species. This study also showed a significant genetic diversity among
accessions from Ethiopia and Eritrea present in the Germplasm Collection of IAC. This diversity is specially observed in accessions
from Sidamo (H′=0,143), Kaffa (H′=0,142) and Illubabor (H′=0,147) indicating their importance as source of genetic variability for coffee breeding programs. 相似文献
3.
O. Ozbek E. Millet Y. Anikster O. Arslan M. Feldman 《Genetic Resources and Crop Evolution》2007,54(7):1587-1598
The aim of the present study was to assess the genetic variation in several Israeli and Turkish populations of wild emmer
wheat, Triticum turgidum ssp. dicoccoides, the progenitor of most domesticated wheat. Single spikes were collected in 2002 from 60 plants that grew in six different
habitats in Ammiad, northeastern Israel (8–12 plants from each habitat), and in 1998 from 56 plants that grew in seven different
habitats in Diyarbakir, southeastern Turkey (8 plants from each habitat). Seeds were planted in a nursery and DNA was extracted
from every plant and analyzed by the fluorescent-based amplified fragment length polymorphism (AFLP) method. Seven primer
combinations produced 788 discernible loci of which 48.6% were polymorphic in Israel and 40.5% in Turkey. The genetic diversity
estimates P (frequency of polymorphic loci) and He (gene diversity) were higher in Ammiad than in Diyarbakir (means of P = 0.34 and He = 0.13 in Ammiad vs. P = 0.20 and He = 0.08 in Diyarbakir). Ammiad populations contained more unique alleles than Diyarbakir populations. The relative genetic
diversity estimates (θ) values were 0.188 in Ammiad and 0.407 in Diyarbakir, suggesting better differentiation of the populations in Turkey. Genetic
distance was larger between Israeli and Turkish populations than between populations of each country. The data indicate that
the Israeli and Turkish populations are considerably diverged and that the Israeli populations are more polymorphic than the
Turkish ones, having a larger within-populations genetic variation than among-populations one. The significance of the results
in relation to the differentiation pattern of wild emmer in the Near East is discussed. 相似文献
4.
Y. Belaïd N. Chtourou-Ghorbel M. Marrakchi N. Trifi-Farah 《Genetic Resources and Crop Evolution》2006,53(7):1413-1418
In order to evaluate the genetic diversity in Lathyrus genus, the Inter Simple Sequence Repeats method (ISSR) was exploited in five populations. These consisted of two cultivated
species belonging to section Lathyrus (L. sativus L. and L. cicera L.) and a wild one belonging to the section Clymenum (L. ochrus DC.). Two 3′anchored ISSR primers and two unanchored ones, generated a total of 60 useful polymorphic DNA bands. Our data
provide evidence of high molecular polymorphism at the intra- and the inter-specific levels showing that both wild and cultivated
forms constitute an important pool of diversity. Moreover, among the generated DNA bands, a 500 bp band, totally absent in
the banding patterns of the section Clymenum, appears to be a molecular marker of section Lathyrus. Results provided for lineage
and suggest recent origin of these species that might have evolved from a common ancestor producing both L. ochrus species and the two other species L. sativus and L. cicera. These relationships support previous studies based on morphological variation and molecular analysis. 相似文献
5.
L. S. Rao P. Usha Rani P. S. Deshmukh P. A. Kumar S. K. Panguluri 《Genetic Resources and Crop Evolution》2007,54(6):1235-1244
Detection of genetic relationships between 19 chickpea cultivars and five accessions of its wild progenitor Cicer reticulatum Ladizinsky were investigated by using RAPD and ISSR markers. On an average, six bands per primer were observed in RAPD analysis
and 11 bands per primer in ISSR analysis. In RAPD, the wild accessions shared 77.8% polymorphic bands with chickpea cultivars,
whereas they shared 79.6% polymorphic bands in ISSR analysis. In RAPD analysis 51.7% and 50.5% polymorphic bands were observed
among wild accessions and chickpea cultivars, respectively. Similarly, 65.63% and 56.25% polymorphic bands were found in ISSR
analysis. The dendrogram developed by pooling the data of RAPD and ISSR analysis revealed that the wild accessions and the
ICCV lines showed similar pattern with the dendrogram of RAPD analysis. The ISSR analysis clearly indicated that even with
six polymorphic primers, reliable estimation of genetic diversity could be obtained, while nearly 30 primers are required
for RAPD. Moreover, RAPD can cause genotyping errors due to competition in the amplification of all RAPD fragments. The markers
generated by ISSR and RAPD assays can provide practical information for the management of genetic resources. For the selection
of good parental material in breeding programs the genetic data produced through ISSR can be used to correlate with the relationship
measures based on pedigree data and morphological traits to minimize the individual inaccuracies in chickpea. 相似文献
6.
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
7.
S. Ganesh Ram K. T. Parthiban R. Senthil Kumar V. Thiruvengadam M. Paramathma 《Genetic Resources and Crop Evolution》2008,55(6):803-809
The genus Jatropha is native of tropical America with more than 200 species that are widely distributed in tropics with a promise for use as
an oil crop for biodiesel. This investigation was carried out to assess the genetic diversity of 12 Jatropha species based on random amplified polymorphic DNA markers. From 26 random primers used, 18 primers gave reproducible amplification
banding patterns of 112 polymorphic bands out of 134 bands scored accounting for 80.2% polymorphism across the genotypes.
Three primers viz., OPA 4, OPF 11, and OPD 14 generated 100% polymorphic patterns. The polymorphic information content was
highest for the primer OPD 14 (0.50) followed by the primers OPF 11 and OPAD 11 (0.48). Jaccard’s coefficient of similarity
varied from 0.00 to 0.85, indicative of high level of genetic variation among the genotypes studied. UPGMA cluster analysis
indicated three distinct clusters, one comprising all accessions of J. curcas L., while second included six species viz., J. ramanadensis Ramam., J. gossypiifolia L., J. podagrica Hook., J. tanjorensis J. L. Ellis et Saroja J. villosa Wight and J. integerrima Jacq. J. glandulifera Roxb. remained distinct and formed third cluster indicating its higher genetic distinctness from other species. The overall
grouping pattern of clustering corresponds well with principal component analysis confirming patterns of genetic diversity
observed among the species. The result provides valid guidelines for collection, conservation and characterization of Jatropha genetic resources. 相似文献
8.
Paula Martins-Lopes José Lima-Brito Sónia Gomes Julieta Meirinhos Luís Santos Henrique Guedes-Pinto 《Genetic Resources and Crop Evolution》2007,54(1):117-128
Thirty Portuguese and eight foreign olive (Olea europaea L.) cultivars were screened using Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeat (ISSR) markers.
Twenty RAPD primers amplified 301 reproducible bands of which 262 were polymorphic; and 17 ISSR primers amplified 204 bands
of which 180 were polymorphic. The percentage of polymorphic bands detected by ISSR and RAPD was similar (88 and 87%, respectively).
The genetic variability observed was similar in the Portuguese and foreign olive cultivars. Seven ISSR and 12 RAPD primers
were able to distinguish individually all 38 olive cultivars. Twenty specific molecular markers are now available to be converted
into Sequence Characterised Amplified Region (SCAR) markers. Relationships among Portuguese and foreign cultivars is discussed. 相似文献
9.
Tileye Feyissa Hilde Nybom Igor V. Bartish Margareta Welander 《Genetic Resources and Crop Evolution》2007,54(5):947-958
Genetic diversity within and among 12 populations of the dioecious tropical tree species Hagenia abyssinica (Bruce) J.F. Gmel. in Ethiopia was examined with eight inter simple sequence repeat (ISSR) primers. A total of 104 clearly
scorable bands were generated, among which 84 (81%) were polymorphic. Jaccard similarity coefficient was calculated for pairwise
comparisons among all 120 individuals and ranged from 0.30 to 0.88 while average within-population similarity ranged from
0.53 to 0.66. Within-population variability was estimated as percentage polymorphic loci (ranging from 52% to 87%), Shannon’s
information index (0.30–0.50) and Nei’s genetic diversity (0.21–0.35). The highest variability values were obtained for one
recently planted population and for one wild population growing in an undisturbed primary forest area. Significant overall
differentiation among populations was detected by both Shannon’s information index (0.26) and G
ST (0.25). Relatedness among samples was estimated with a principal coordinate analysis, and relatedness among populations was
estimated with a cluster analysis (UPGMA). A Mantel test indicated a significant association between genetic and geographic
distances, and an autocorrelation analysis showed significant evidence of gene flow over distances up to 30 km. This study
is the first of its kind for H. abyssinica, which has decreased recently in Ethiopia and now must be regarded as an endangered species. Both within-population and between-population
diversity estimates are typical of outcrossing, longlived and late successional species, suggesting that recent anthropogenic
disturbances have not yet had much impact on population genetic parameters. DNA marker data can, however, be used to identify
the most suitable sites for in situ conservation and for collection of material for establishment of genebanks and plant improvement programs. 相似文献
10.
Ilaria Marotti Alessandra Bonetti Maurizio Minelli Pietro Catizone Giovenni Dinelli 《Genetic Resources and Crop Evolution》2007,54(1):175-188
Randomly amplified polymorphic DNA (RAPD), inter-simple sequence repeat (ISSR) and a semi-random PCR system were used to analyze
the genetic diversity of 16 Italian common bean landraces and their relationship to four commercial cultivars. Of the primers
tested, 8 ISSR, 6 RAPD and 7 semi-random primers produced polymorphic and reproducible DNA fragments. A higher proportion
of polymorphic bands were observed using ISSR (85%) and semi-random (90%) primers than RAPD (69%) method. The combination
of any two semi-random markers allowed the identification of all 20 bean genotypes. In contrast ISSR (except for primer (CAC)3GC) and RAPD markers appeared to be less informative as more than two markers were necessary to achieve the same diagnostic
level. Moreover, 7 ISSR, 2 RAPD and 8 semi-random exclusive bands were identified as putative population-specific markers.
Semi-random and ISSR derived dendrograms showed similar tendencies in terms of genetic relatedness, whereas clustering of
genotypes within groups was not similar when compared with the RAPD technique. Despite the different ability to resolve genetic
variation among the investigated landraces, two major clusters with less than 60% (ISSR) and 40% (RAPD and semi-random) genetic
similarity were formed with all three marker systems. The two groups were correlated with the phaseolin patterns and seed
size of the landraces. The analysis showed that the cultivar ȁ8Lingua di Fuocoȁ9 and most of the landraces (13 out of 16)
collected in Italy belong to the Andean gene pool, whereas only the three populations from Pratomagno belong to the Middle
American gene pool. 相似文献
11.
Marie Malice Nicolas Martin Audrey Pissard Jorge A. Rojas-Beltran Antionio Gandarillas Pierre Bertin Jean-Pierre Baudoin 《Genetic Resources and Crop Evolution》2007,54(4):685-690
ISSR molecular markers have been used to investigate genetic diversity of oca (Oxalis tuberosa Mol.), an Andean neglected tuber crop species. Sampling procedure allowed a preliminary study of the genetic diversity at
the intra- and intervarietal levels. Twenty tuber lots conserved in situ in the microcentre of Candelaria and ex situ in the Toralapa Centre (Bolivia) were identified. Four ISSR primers amplified a total of 25 fragments of which 17 (68%) were
polymorphic. These experiments show that the structure of oca varieties is mainly based upon vernacular names with a greater
differentiation among tuber lots than within them, supporting agromorphological data. ISSR technique enlightened the existence
of heterogeneous varieties in oca and divergence between in situ and ex situ conservation strategies. These observations are potentially linked to the different ways of management of tubers in these
two conservation systems. 相似文献
12.
Toan Duc Pham Tri Minh Bui Gun Werlemark Tuyen Cach Bui Arnulf Merker Anders S. Carlsson 《Genetic Resources and Crop Evolution》2009,56(5):679-690
Sesame (Sesamum indicum L.) is a traditional oil crop cultivated throughout South East Asia. To estimate the genetic diversity of this crop in parts
at the region, 22 sesame accessions collected in Vietnam and Cambodia were analyzed using 10 RAPD markers. The 10 primers
generated 107 amplification products of which 88 were polymorphic fragments (83%). Genetic diversity of all populations was
Ht = 0.34 when estimated by Nei’s genetic diversity and species diversity was H′sp = 0.513 when estimated by Shannon diversity index. Genetic distance ranged from 0.03 to 0.43, with a mean genetic distance
of 0.23. The unweighted pair group method with arithmetic averages (UPGMA) cluster analysis for the 22 accessions divided
the material in four groups. The dendrogram revealed a clear division among the sesame accessions based on their geographical
region. Interestingly, some geographically distant accessions clustered in the same group, which might indicate the human
factor involved in the spreading of sesame varieties. The high level of polymorphism shown suggests that RAPD techniques can
also be useful for the selection of parents in sesame (Sesamum indicum L.) breeding program and for cultivar differentiation. 相似文献
13.
Edurne Aguiriano Magdalena Ruiz Rosario Fité Jose M. Carrillo 《Genetic Resources and Crop Evolution》2006,53(8):1543-1552
In this work gliadin proteins were used to analyse the genetic variability in a sample of the durum wheat Spanish collection
conserved at the CRF-INIA. In total 38 different alleles were identified at the loci Gli-A1, Gli-A3, Gli-B5, Gli-B1, Gli-A2 and Gli-B2. All the gliadin loci were polymorphic, possessed large genetic diversity and small and large differentiation within and
between varieties, respectively. The Gli-A2 and Gli-B2 loci were the most polymorphic, the most fixed within varieties and the most useful to distinguish among varieties. Alternatively,
Gli-B1 locus presented the least genetic variability out of the four main loci Gli-A1, Gli-B1, Gli-A2 and Gli-B2. The Gli-B1 alleles coding for the gliadin γ-45, associated with good quality, had an accumulated frequency of 69.7%, showing that the
Spanish germplasm could be a good source for breeding quality. The Spanish landraces studied showed new gliadin alleles not
catalogued so far. These new alleles might be associated with specific Spanish environment factors. The large number of new
alleles identified also indicates that durum wheat Spanish germplasm is rather unique. 相似文献
14.
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
15.
All the 79 Aegilops tauschii Coss. accessions of Iranian origin from Prof. Kihara’s collection were analyzed electrophoretically. Of 23 enzyme-encoding
loci studied, 11 were polymorphic. In Iran Ae. tauschii is presented by ssp. tauschii and ssp. strangulata which distinctly differ genetically, morphologically and ecologically. Variation patterns of low polymorphic locus Aco2 and highly polymorphic Ep are similar in both subspecies. In contrast, variation of Acph1, Ak, Est2, Est5, Got1, Got2, Got3 and Lap is a set of diverse patterns which markedly differ between subspecies and natural regions also, implying that natural selection
is involved. 相似文献
16.
Inter Simple Sequence Repeat (ISSR) Analysis of Diploid Coffee Species and Cultivated Coffea arabica L. from Tanzania 总被引:1,自引:0,他引:1
Inter simple sequence repeat (ISSR) markers were used to evaluate levels of genetic similarity among Coffea arabica L. accessions from Tanzania and to estimate levels of genetic similarities in C. arabica and diploid coffee species. The six ISSR primers used generated a total of 82 fragments and the dissimilarity values ranged
from 0.21 to 1. Mean dissimilarity values between provenances (0.56–0.85) were higher than within provenances (0.37–0.68).
Cluster analysis based on Nei’s genetic distances showed C. arabica provenances grouping based on geographical origin. Two major clusters were formed that constituted of provenances from Kilimanjaro
and Arusha in one sub-cluster; Tanga and Morogoro in the other; the second cluster had Mbeya provenances and diploid species,
respectively. The implication is that Mbeya provenances are different from the rest of Tanzanian C. arabica. A principal coordinate analysis (PCA), whose first three coordinates explained 43% of the variation, showed similar groupings
as in the cluster analysis. A separate cluster analysis of diploid species showed a distinct separation of the three species
used. ISSR data gave results similar to previous findings from random amplified polymorphic DNA(RAPD) analysis. The results
also confirm the limited diversity present in cultivated C. arabica in Tanzania 相似文献
17.
Random amplified polymorphic DNA markers were used to study sub-structure and genetic differentiation amongst 31 populations
(seven cultivated and 24 wild populations) belonging to 14 Asiatic Vigna species. Ten pre-selected RAPD primers generated 152 polymorphic amplification products. Estimates of polymorphism indices
were higher for the wild taxa in comparison to the cultivated forms. FST values between populations ranged from 0.111 to 0.801 and Nei’s genetic diversity values between and within species varied
from 0.26 to 0.70 and 0.04 to 0.56 respectively. The high FST and FCT values indicated strong subdivision of populations and high differentiation among species. Analysis of molecular variance
was performed by grouping the populations conforming to specific species. AMOVA was also performed separately to better resolve
the differentiation of species within mungo–radiata complex. Molecular phylogenetic relationships amongst the species of radiata–mungo complex; namely, black gram (V. mungo (L.) Hepper), green gram (V. radiata (L.) Wilczek), V. radiata var. sublobata, V. radiata var. setulosa, V. mungo var. silvestris and V. hainiana, were studied through cluster analyses. Two distinct groups were recognized within the complex, with population samples of
V. hainiana forming one cluster. Further, V. hainiana appeared to be equidistant to both V. radiata and V. mungo. 相似文献
18.
Hiroko Takahashi Bhuwan Rai Kenji Kato Ikuo Nakamura 《Genetic Resources and Crop Evolution》2010,57(1):101-109
Triticum timopheevii (genome symbol AAGG) comprises two subspecies, cultivated ssp. timopheevii, and wild ssp. armeniacum. These two subspecies are considered as allotetraploids of AA genome from Triticum diploid species and SS genome from Aegilops species. The difference in genome symbol (G vs. S) is due to wide genetic variations among four SS genome species, Ae. bicornis, Ae. longissima, Ae. searsii, and Ae. speltoides. In order to study the origin of T. timopheevii, we compared 19th intron (PI19) sequence of the PolA1 gene, encoding the largest subunit of RNA polymerase I. Two different sized DNA fragments containing PI19 sequences (PI19A
and PI19G) were amplified both in ssp. timopheevii and ssp. armeniacum. Shorter PI19A (112 bp) sequences of both subspecies were identical to PI19 sequences of two AA species, T. monococcum and T. urartu. Interestingly, the longer PI19G (241–243 bp) sequences of ssp. armeniacum showed more similarity to PI19 sequences of Ae. speltoides whereas ssp. timopheevii showed more similarity to PI19 sequences of other three SS genome species. The results indicated that two subspecies of T. timopheevii, ssp. armeniacum or ssp. timopheevii, might have arisen independently by allotetraploidization of AA genome with Ae. speltoides or one of the remaining three Aegilops species, respectively. 相似文献
19.
Anna Geraci Anne-Marie Chèvre Isabelle Divaret Frédérique Eber Francesco M. Raimondo 《Genetic Resources and Crop Evolution》2004,51(2):137-146
In Sicily and in the small surrounding islands the section Brassica of the genus Brassica comprises five species, B. insularis Moris, B. incana Ten., B. macrocarpa Guss., B. rupestris Raf. and B. villosa Biv. These taxa represent a genetic resource as relatives of kale crops but some populations are endangered or threatened, thus isozyme analyses were performed to assess the genetic diversity degree at population and species levels in order to assist the design of conservation management programs.Eleven loci from five enzyme systems (aconitase, leucine aminopeptidase, 6-phosphogluconate dehydrogenase, phosphoglucoisomerase phosphoglucomutase) were analyzed in sixteen natural population (fifteen from Sicily, one from Calabria). Mean within-population genetic diversity was moderate (P = 41%, A = 1.54, H = 0.16). In some cases a great number of heterozygous individuals were detected, in other cases fixation index (F) deviated significantly from Hardy-Weinberg genotypic expectations.A total of 37 alleles was recognized, six of which resulted exclusive to single populations. The among-population component of the total genetic diversity (Gst mean values) for each species was 0.30–0.37, indicating genetic differentiation among populations.Among B. villosa and B. rupestris populations genetic distance values resulted rather low and they resulted high with B. incana and B. macrocarpa populations.The results are discussed with regard to the distribution of the genetic diversity level and the genetic resources management. 相似文献
20.
Fernanda Witt Cidade Miguel Dall’Agnol Fernanda Bered Tatiana Teixeira de Souza-Chies 《Genetic Resources and Crop Evolution》2008,55(2):235-246
The genus Paspalum L. comprises approximately 400 species worldwide and about 220 in Brazil. Paspalum is ecologically and economically important, and has been very useful as pasture and P. notatum Flügge (bahiagrass) is a valuable forage grass in the subtropics. This species consists of several sexual (diploid) and apomictic
(tetraploid, ocasionally tri and pentaploids) biotypes. In this work, inter simple sequence repeats (ISSR) markers were used
to assess the genetic variability of a bahiagrass (P. notatum) collection. Vegetative tissues of 95 bahiagrass accessions were obtained from various locations in South America (Brazil,
Argentina and Uruguay). A total of 91 reproducible ISSR fragments were observed and 89 fragments (97.5% of the total observed)
were polymorphic. Cluster analyses (UPGMA) were performed from the ISSR data set and the results illustrate the genetic relationships
among the 95 accessions of P. notatum. A comparison among molecular, morphological and ploidy levels data were done. ISSR markers were effective in distinguishing
the genotypes analyzed, and a wide variability was observed for this species. These results add new information regarding
the genetic diversity in P. notatum, thus contributing toward the biological knowledge of this species, and providing with subsides for future plant breeding
and conservation programs. 相似文献