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1.
N. P. S. Dhillon R. Ranjana Kuldeep Singh I. Eduardo A. J. Monforte M. Pitrat N. K. Dhillon P. P. Singh 《Genetic Resources and Crop Evolution》2007,54(6):1267-1283
Diversity among 36 snapmelon landraces, collected from 2 agro-ecological regions of India (9 agro-climatic sub-regions), was
assayed using RAPD primers, morphological traits of plant habit and fruit, 2 yield-associated traits, pest and disease resistance
and biochemical composition (TSS, ascorbic acid, titrable acidity). Typical differences among accessions were observed in
plant and fruit characteristics and snapmelon germplasm with high titrable acidity and possessing resistance to downy mildew,
Cucumber mosaic virus, Zucchini yellow mosaic virus, Papaya ringspot virus, Aphis gossypii and Meloidogyne incognita was noticed in the collection. RAPD based grouping analysis revealed that Indian snapmelon was rich in genetic variation
and region and sub-region approach should be followed across India for acquisition of additional melon landraces. Accessions
of var. agrestis and var. momordica clustered together and there was a separate cluster of the accessions of var. reticulatus. Comparative analysis of the genetic variability among Indian snapmelons and an array of previously characterized reference
accessions of melon from Spain, Israel, Korea, Japan, Maldives, Iraq, Pakistan and India using SSRs showed that Indian snapmelon
germplasm contained a high degree of unique genetic variability which was needed to be preserved to broaden the genetic base
of melon germplasm available with the scientific community.
N. P. S. Dhillon and Ranjana contributed equally to this work and are considered the first authors. 相似文献
2.
Nasab K. Rawashdeh Nasri I. Haddad Mohamad M. Al-Ajlouni Munir A. Turk 《Genetic Resources and Crop Evolution》2007,54(1):129-138
Durum wheat landrace genotypes are disappearing from the main wheat areas in Jordan, because of spreading of new uniform cultivars
and the serious reduction in wheat cultivation. This study was conducted to evaluate genetic diversity in durum wheat landraces
from Jordan and to identify desirable agronomic traits. Landraces were collected from two target areas: Ajloun and Karak.
The collected material was grown under rainfed conditions using an augmented design with five blocks and four repeated check
cultivars. Data were collected for 14 morphological and agronomic traits. Phenotypic diversity index (H′) was estimated, and
the relationships among accessions were measured using cluster analysis and dendrogram similarity matrix. The results revealed
the presence of a wide range of variability among landraces., which possess high levels of variability for biological yield,
fertile tillers, number of seeds per spike, seed weight per spike and weight of 1000 seeds. These landraces must be considered
as a reservoir of genes that plant breeders need in their wheat improvement programs and should be conserved both ex situ and in situ. 相似文献
3.
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
4.
A. Kolodinska Brantestam R. von Bothmer C. Dayteg I. Rashal S. Tuvesson J. Weibull 《Genetic Resources and Crop Evolution》2007,54(4):749-758
To examine changes in the level of and pattern in variability in 197 Nordic and Baltic spring barley cultivars over time we
used 21 mapped barley simple sequence repeats (SSRs). A total number of 191 alleles were found from 22 SSR loci. The number
of alleles per locus ranged from 2 to 23, with average of 8.63 107 alleles were rare (frequency <0.05) among the cultivars
and only one allele was frequently observed (frequency >0.95). The gene diversity between loci in Nordic and Baltic material
varied between 0.033 and 0.891. Average gene diversity was 0.623. The SSR data separated two-rowed and six-rowed cultivars.
According to analysis of molecular variance (AMOVA) differentiation in two-rowed vs six-rowed accounted for 23.6% of the total
variation. Overall no significant decrease of average gene diversity over time could be found. However, differences were observed
when spring barleys from northern (north of ∼58°) and southern (south of ∼58°) parts of the Nordic and Baltic area were compared.
For the southern ecogeographical region significant decrease of genetic diversity was observed in the middle of the 20th century,
whereas no significant changes in the northern part were found. We found larger differentiation between modern and old cultivars
in the South compared to the ones in North parts of the region. The magnitude of changes in genetic diversity differed also
with the country of origin. Danish cultivars had a significant decrease in diversity in the middle of century, whereas changes
in Finland, Norway and Sweden were not significant. 相似文献
5.
Christopher M. Richards Michael F. Antolin Ann Reilley Jackie Poole Christina Walters 《Genetic Resources and Crop Evolution》2007,54(4):837-848
Genebanks complement other conservation programs because they preserve genetic diversity needed for future breeding and restoration.
We evaluated efficiency of capturing genetic diversity, using endangered Zizania texana (Texas wild rice) as a model for plants with recalcitrant seeds. This perennial aquatic grass is restricted to 4 km of the
San Marcos River in Texas. An early conservation collection included plants from stands throughout the river, based on the
assumption stands would be unique genotypes. Using microsatellite markers, we found that genetic diversity was concentrated
in five of 15 large, demographically stable stands; 96 stands smaller than 2 m2 contributed no unique alleles. High heterozygosity and few duplicate genotypes suggested that sexual reproduction occurs
more often than presumed. Simulations of stratified sampling of large stands captured all alleles in only 45 individuals,
while random sampling along the river captured much less diversity. The early conservation collection captured as much diversity
as expected from random sampling. Texas wild rice stands resemble a mainland-island metapopulation; our analyses suggest that
stratified sampling maximizes genetic diversity for this population dynamic. Demographic and genetic information is important
for validating the design of efficient ex situ collections and guiding in situ conservation. 相似文献
6.
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
7.
Gemechu Keneni Mussa Jarso Tezera Wolabu Getnet Dino 《Genetic Resources and Crop Evolution》2005,52(5):551-561
A field experiment was conducted in 2001 at Holetta and Kulumsa, Ethiopia, to study genetic diversity in Ethiopian faba bean
(Vicia faba L.) landraces. One hundred sixty random germplasm accessions were grown in an alpha lattice design with two replications. Data
on 12 traits were collected and analyzed. Significant differences were observed among the accessions for most of the traits
(except number of pods/podding nodes) at each location even though differences pooled over location were mostly non-significant.
Cluster analysis distinguished seven diversity classes of different sizes. Accessions from the northern half of the country
(North and South Wello, North Gonder and North Shewa) were closely related while those from the southern part of the country
(Arsi) were highly diverse. Cumulative effects of a number of characters dictated differentiation of the accessions into clusters.
Some overlapping were encountered between accessions from the northern and those from the southern parts of the country. The
study revealed that accessions from different regions might have similar genetic background and those from the same origin
might also have different genetic background. Therefore, geographic diversity should not necessarily be used as an index of
genetic diversity and parental selection should be based on a systematic study of genetic diversity in a specific population.
Genetic distances between most of the clusters were significant that crosses between parents selected out of them are expected
to generate desirable progenies. Future germplasm collection, conservation and utilization strategies should put more focus
not only on inter-regional diversity in the country as a whole but also on intra-regional diversity in Arsi. 相似文献
8.
M. C. Vaz Patto P. M. Moreira V. Carvalho S. Pego 《Genetic Resources and Crop Evolution》2007,54(7):1555-1563
The Portuguese maize bread (“broa”) manufactured from traditional maize landraces still plays an important economic and social
role on Central and Northern rural communities of the country. However the traditional maize landraces agricultural systems
are changing. Local maize landraces are in risk of disappearing because of the progressive adoption of hybrid varieties not
suitable for bread production. These changes are contributing to a major loss of genetic diversity. An expedition took place
in the Central region of Portugal (Beira Interior and Beira Litoral) with the purpose of collecting enduring maize landraces
with technological ability for bread production and to access the possibility of establishing a participatory plant breeding
and conservation program. A total of 51 different maize landraces and 175 other varieties of associated crops were collected.
Maize landraces showed to maintain high diversity and potential for improvement. The production relayed on small farms with
polycrop, quality oriented, sustainable systems. A participatory plant breeding and conservation program would be possible
on this region with the proviso that local authorities would be involved. This program would allow a higher valuation of these
maize populations, contributing to halt the current loss of these unique Portuguese maize landraces. 相似文献
9.
Bettina Heider Elke Fischer Tanja Berndl Rainer Schultze-Kraft 《Genetic Resources and Crop Evolution》2007,54(3):529-542
Pueraria montana var. lobata and P. phaseoloides originating from tropical Asia and parts of Oceania are ecologically and economically important legumes that are used as
green manure, cover crop or forage plants. Conservation and use of plant genetic resources require an understanding of the
extent and distribution of genetic diversity in any given region. In this study, genetic variation of five P. montana var. lobata and 16 P. phaseoloides accessions was analysed developing a random amplified polymorphic DNA (RAPD) marker methodology for Pueraria species and thereby creating basic data for follow-up research and the development of conservation strategies. Seeds were
collected from native populations in Bac Kan Province, a mountainous region in Northeast Vietnam. P. montana var. lobata presented a high level of variation with 54.3% of the detected markers being polymorphic, whereas P. phaseoloides exhibited an intermediate to high level of variation (45.5%). The P. montana var. lobata accessions clustered in congruence with their eco-geographical origin. For P. phaseoloides no correspondence between sampling sites and genetic differentiation was found. Inter-population differentiation was measured
as Jaccard's similarity coefficient (JSC). Mean JSC amounted to 0.35 in P. montana var. lobata and 0.52 in P. phaseoloides. Results are compared to other genetic studies of herbaceous legumes and conservation strategies are suggested. 相似文献
10.
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.
Mulatu Geleta Tomas Bryngelsson Endashaw Bekele Kifle Dagne 《Genetic Resources and Crop Evolution》2007,54(3):601-614
Genetic diversity of 70 populations of niger (Guizotia abyssinica) representing all its growing regions in Ethiopia was investigated using random amplified polymorphic DNA (RAPD) to reveal
the extent of its populations genetic diversity. Ninety-seven percent of the loci studied was revealed to be polymorphic for
the whole data set. The within population diversity estimated by Shannon diversity index and Nei gene diversity estimates
was revealed to be 0.395 and 0.158, respectively. The extent of genetic variation of populations from major niger producing
regions was significantly lower than that of populations from other regions; however, it is distributed regardless of altitude
of growth. Genetic differentiation between populations was estimated with Shannon index as G′
ST (0.432), Nei’s G
ST (0.242) and AMOVA based F
ST (0.350) and appears to be equivalent to the average values calculated from various RAPD based studies on outcrossing species.
Higher proportion of the variation detected by AMOVA resided within populations (64.58%) relative to the amount of variation
among populations (35.42%). UPGMA cluster analysis showed that most of the populations were clustered according to their region
of origin. However, some populations were genetically distant from the majority and seem to have unique genetic properties.
It is concluded that the crop has a wide genetic basis that may be used for the improvement of the species through conventional
breeding and/or marker assisted selection. Collection of germplasm from areas not yet covered and/or underrepresented is the
opportunity to broaden the genetic basis of genebank collection. 相似文献
13.
Antonio M. De Ron María C. Menéndez-Sevillano Marta Santalla 《Genetic Resources and Crop Evolution》2005,51(8):883-894
The phenotypic variation found in four common bean (Phaseolus vulgaris L.) complex primitive landraces, among a group of accessions collected in Northwestern Argentina in several missions is described, with particular attention to the wide diversity found in some small areas. It is presented a hypothesis about the maintenance of such diversity in bean mixtures or complex primitive landraces that grow close to their wild relative. Wide diversity regarding to seed type and plant characteristics was displayed by the landraces MCM-SV (composed of 11 lines), MCM-292 (14 lines), MCM-298 (5 lines) and VAV-3716 (14 lines). Food uses of dry seed and fresh pod seemed to be more relevant than the aesthetic use although all of them were presumably considered by humans for centuries resulting in the current phenotypes of these complex primitive landraces. Additionally, some weedy types (intermediate between wild and domesticated types) were detected in the landracesMCM-292 and MCM-298. The four complex landraces described consisted of highly diverse mixtures and they could play a role in breeding to enlarge the genetic basis of domesticated bean varieties belonging to the Andean gene pool. 相似文献
14.
Y. -B. Pan D. M. Burner B. L. Legendre M. P. Grisham W. H. White 《Genetic Resources and Crop Evolution》2005,51(8):895-903
A local collection of 33Saccharum spontaneum L. clones and two sugarcane cultivars (LCP 82-89 and LCP 85-384) were assessed for genetic variability using random amplified polymorphic DNA (RAPD)-PCR. A total of 157 polymorphic RAPD-PCR bands were scored with 17 primers. The number of RAPD-PCR products per primer ranged from four to 16. The data were analyzed with two multivariate analysis software programs, NTSYSpc and DNAMAN®. Although these two programs yielded similar results, a bootstrapped phylogenetic tree could only be generated with the DNAMAN® software. A substantial degree of genetic diversity was found within the localS. spontaneum collection. Pairwise genetic homology coefficients ranged from 65% (SES, 196/Tainan 2n = 96) to 88.5% (IND 81-80/IND 81-144). LCP 82-89 and LCP 85-384 shared a greater similarity (82%) than either was to any clone ofS. spontaneum (ranging from 60.5 to 75.2%). The 33S. spontaneum clones were assigned to eight groups independent of their geographic origin or morphology, while the two sugarcane cultivars were assigned to the ninth group. All but two pairs ofS. spontaneum clones could be distinguished by a single RAPD primer OPBB-02. The use of a second primer, either OPBE-04 or Primer 262, separated allS. spontaneum clones. One amplification product from the RAPD primer OPA-11, OPA-11-336, proved to be cultivar-specific and has been adopted for use in our breeding program. Information from this study would help conserve the genetic diversity ofS. spontaneum.
Disclaimer: Product names and trademarks are mentioned to report on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA does not imply the approval of the product to the exclusion of others that may also be suitable. The experiments reported comply with the current laws of the USA. 相似文献
15.
Marc Moragues Marian Moralejo Mark E. Sorrells Conxita Royo 《Genetic Resources and Crop Evolution》2007,54(5):1133-1144
A comprehensive characterization of crop germplasm is critical to the optimal improvement of the quality and productivity
of crops. Genetic relationships and variability were evaluated among 63 durum wheat landraces from the Mediterranean basin
using amplified fragment length polymorphisms (AFLPs) and microsatellites markers. The genetic diversity indices found were
comparable to those of other crop species, with average polymorphism information content (PIC) values of 0.24 and 0.70 for
AFLP and microsatellites, respectively. The mean number of alleles observed for the microsatellites loci was 9.15. Non-metric
multi-dimensional scaling clustered the accessions according to their geographical origin with the landraces from the South
shore of the Mediterranean Sea closely related. The results support two dispersal patterns of durum wheat in the Mediterranean
basin, one through its north side and a second one through its south side. 相似文献
16.
17.
Hong Bo Guo Bao Rong Lu Qian Hong Wu Jia Kuan Chen Tong Shui Zhou 《Genetic Resources and Crop Evolution》2007,54(5):917-924
Genetic diversity of seven cultivated populations of Codonopsis pilosula Nannf. from Longxi County, Gansu Province of China was estimated using randomly amplified polymorphic DNA (RAPD) markers.
The 17 selected RAPD primers amplified 205 polymorphic bands out of a total of 235 (87.2%). Nei’s gene-diversity statistics
and population differentiation parameters based on AMOVA analysis indicated that the cultivated C. pilosula populations remained a high level of genetic diversity with Hs = 0.299 and I = 0.450. A greater proportion of genetic diversity was found within (77%) rather than among (23%) the populations. In addition,
we also detected that populations from different altitudes had a considerable genetic differentiation after 40 years of cultivation
at the same site. Populations from higher altitude had lower genetic diversity than those from lower altitude. Our results
suggested that irregular and sparse cultivation practices, i.e., random collecting, preserving, and planting seeds of the
medicinal species without deliberate selection, might be an efficient way to conserve genetic resources of medicinal plants,
in addition to their effective uses. 相似文献
18.
R. Alonso Ferro I. Brichette G. Evgenidis Ch. Karamaligkas J. Moreno-González 《Genetic Resources and Crop Evolution》2007,54(2):295-308
An European maize (Zea mays L.) landrace core collection (EMLCC) was formed with samples from several countries. Evaluation of the EMLCC may contribute
to broad the genetic base of maize breeding programs. The objective of this study was to assess the variability of EMLCC under
low nitrogen (N) in relation to high N input. Eighty-five landraces of the EMLCC, grouped in four maturity groups, and three
check hybrids were evaluated for response to low (0 kg ha−1) and high (150 kg ha−1) N in Spain and Greece. Five plant size traits (plant height, ear height, leaf length, leaf width and leaf area index), two
grain traits (1000-kernel weight and grain yield), and two agronomic traits [growing degree units (GDU) and lodging] were
studied. Overall means of plant size and grain traits increased when genotypes were grown at 150-N relative to 0-N input.
The relative increase for grain traits was smaller in landraces than in hybrids. This suggests that landraces had lower grain
yield response to N supply compared to hybrids. Linear regressions of plant size traits on GDU indicated that vegetative development
was primarily associated with flowering lateness. The maturity group was the main source of variation for all traits. Landrace
variability within maturity groups was significant for all traits across environments, despite significant landrace × environment
interactions. Estimates of genetic and genotype × environment variances, and heritabilities at both high and low N inputs
were not significantly different from each other. However estimates were generally larger at high N. Genetic and phenotypic
correlation coefficients between the two N levels were very high for all traits. 相似文献
19.
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
20.
The eleven most known landraces from central and southern Italy were analysed using ISSR markers on 15 randomly chosen individuals
for each landrace, with the aim of assessing genetic variation within and among landraces and possibly ascertaining their
origin and genetic relationships. A total of 164 loci were observed, 128 of which (78.05%) were polymorphic. Gene diversity
over all landraces was I = 0.3759. The highest within-landrace diversity was observed in samples from the Apennine ridge and for one Sicilian landrace;
on the other hand, samples from the small Sicily islands were less variable. Principal Component Analysis and AMOVA allowed
the discrimination of groups of landraces with higher similarity. Analyses indicate that the small Sicily islands landraces
are very closely related to one another and seem to be derived from the peninsular material; moreover, they help disclose
relationships among geographically close landraces. The knowledge so acquired can, therefore, contribute to elaborate strategies
for increasing the economical value of élite landraces and to protect producers from frauds. 相似文献