Étude des index d'ADN de huit espèces d'ignames (Dioscorea sp.) par cytométrie en flux

1992 ◽  
Vol 70 (5) ◽  
pp. 996-1000 ◽  
Author(s):  
Perla Hamon ◽  
Jean-Paul Brizard ◽  
Jeanne Zoundjihékpon ◽  
Christophe Duperray ◽  
Alain Borgel

Nine species (wild and cultivated) and some interspecific (wild × cultivated) hybrids were analysed by flow cytometry. This study confirms various polyploidy levels within cultivated species. DNA index varied by a factor of 1 to 3 for Dioscorea alata, 1 to 2.25 for Dioscorea bulbifera, and 1 to 2 for Dioscorea cayenensis-rotundata, depending on the clone or cultivar considered. In wild species, only one DNA index per species was obtained. Whenever a relationship between DNA index and chromosome number could be established, the size of genome 1C was evaluated in picograms and base pairs. Two genome sizes were observed: genome A in D. cayenensis-rotundata, Dioscorea abyssinica, Dioscorea mangenotiana, and Dioscorea praehensilis and genome B in Dioscorea togoensis. These genomes were small sizes, only 1.5 to 2.1 times larger than that of Arabidopsis. Key words: yams, Dioscorea, flow cytometry, DNA index, genome size.

Author(s):  
N. A. Kanu ◽  
T. L. Kingsley

The sensory characteristic can be quantified and defined by the use of the descriptive profile. A different cultivar of yam can be used for the production of poundo yam. The standard of a product is determined by the evaluation and its acceptability by a taste panelist. Four cultivars of yam; Dioscorea alata, Dioscorea cayenensis, Dioscorea rotundata and Dioscorea bulbifera were sourced and processed into flour. Moringa seed oleifera was defatted and the cake was blended at a different concentration of 5% and 10% with the yam flour. The qualitative phytochemical investigation of the yam flour and Moringa oleifera seed revealed the presence of, alkaloids, steroids, terpenoid oxalate, anthraquinone, phenol, saponins, tannins and flavonoids. Quantitative analysis showed that among the control samples Dioscorea alata (DAC), Dioscorea Dioscorea bulbifera (DBC), cayenensis (DCC) and Dioscorea rotundata (DRC). DRC and DAC have the highest values in the total phenol and total flavonoids. Dioscorea cayenensis recorded the highest value in steroid and saponin content. The flavonoids, steroid and terpenoid were improved by the inclusion of moringa seed meal at 5% and 10%. The result of the sensory analysis revealed that panellist preferred DRC in term of moldability, texture, taste and general acceptability. However, the samples with moringa seed meal at 5% and 10% inclusion compete favourably with the control samples. The inclusion of Moringa oleifera seed meal at 10% improved the pounded yam and was more accepted than the 5% in term of general acceptability.


2009 ◽  
Vol 61 (4) ◽  
pp. 847-851 ◽  
Author(s):  
A.A. Abdulrahaman ◽  
F.O. Egbedo ◽  
F.A. Oladele

Dioscorea alata L. has three stomatal complex types, namely, paracytic, anisocytic, and tetracytic stomata, with percentage frequency values of 50, 18, and 32, respectively. Dioscorea bulbifera has paracytic and anisocytic stomata, with percentage frequency values of 87.60 and 12.40, respectively. Dioscorea cayenensis has anisocytic stomata, with a percent?age frequency value of 100. Dioscorea dumetorum has tetracytic and paractytic stomata, with percentage frequency values of 91.05 and 8.95, respectively. Both D. esculenta and D. rotundata have paracytic stomata, with a percentage frequency of 100. The range of variation of stomatal density is from 10 (lowest value) in D. alata and D. dumentorum to 27 (highest value) in D. bulbifera. The stomatal index also varies, from 24 in D. alata to 47 in D. cayenensis. The size of stomata in all species is small, varying in length from 0.74 ?m in D. alata to 1.79 ?m in D. dumentorum. An indented dichotomous key based on stomatal features was constructed to distinguish and identify the species.


Genome ◽  
2000 ◽  
Vol 43 (3) ◽  
pp. 470-476 ◽  
Author(s):  
A M Kiers ◽  
T HM Mes ◽  
R van der Meijden ◽  
K Bachmann

The genus Cichorium consists of two widely cultivated species C. intybus (chicory) and C. endivia (endive) and four wild species, C. bottae, C. spinosum, C. calvum, and C. pumilum. A multivariate and an UPGMA (unweighted pair group method average) analysis based on AFLP (amplified fragment length polymorphism) markers were used to establish the genetic relationships among the species and cultivar groups of C. intybus and C. endivia. At the species level, the results correspond with previously obtained phylogenetic relationships in that C. bottae is the most divergent species, and C. intybus and C. spinosum, as well as C. endivia, C. pumilum, and C. calvum formed clusters. Based on the congruence between phylogenetic and genetic analyses, unique markers were expected for all species, however, hardly any specific marker was found except for C. bottae. The analysis of cultivar groups of C. intybus resembled the species analysis in two respects: (i) grouping of cultivars according to cultivar groups, and (ii) lack of markers unique to cultivar groups. In contrast to C. intybus, the cultivar series of C. endivia do not form distinct groups, which would reflect that crosses have been made among the various cultivar groups. The relationships among Cichorium species and cultivars will be useful for setting up a core collection of Cichorium, and stress the importance of inclusion of the wild species in the collection.Key words: Cichorium, AFLP, diagnostic markers, cultivar relationships, genetic resources.


1986 ◽  
Vol 72 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Raffaella Uccelli ◽  
Alberto Calugi ◽  
Donato Forte ◽  
Francesco Mauro ◽  
Paolo Polonio-Balbi ◽  
...  

The relative DNA content of cellular samples from 54 patients affected by breast carcinomas and 20 affected by benign breast lesions (including 11 fibroadenomas) was measured by flow cytometry. All normal tissue samples and 17/20 (85%) specimens from benign lesions exhibited a cytometrically diploid DNA distribution, 3/20 (15%) benign lesions an abnormal DNA content, and 35/54 (65%) carcinomas at least one aneuploid cell subpopulation. Furthermore, 9/54 (17%) tumors were characterized by the presence of more than one aneuploid cell subpopulation. The results also indicate that flow cytometry can be used to recognize lymph nodes infiltrated by aneuploid cells. Statistically significant correlations were evidenced between the occurrence of aneuploidy or the ploidy level measured as DNA index and the nodal infiltration status. The percentage of S cells can also be extracted from DNA content distribution histograms. Statistically significant differences (p < 0.01) were also observed for the percentage of S cells between normal tissues (6.2±3.2 SD) and benign lesions (11.1±6.6 SD), normal tissues (6.2 ± 3.2 SD) and aneuploid tumors (19.7 ± 10.3 SD), benign lesions (11.1 ± 6.6 SD) and aneuploid tumors (19.7 ± 10.3 SD), and diploid (7.9 ± 4.0 SD) and aneuploid tumors (19.7 ± 10.3 SD).


CYTOLOGIA ◽  
1990 ◽  
Vol 55 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Jeanne Zoundjihekpon ◽  
Sadi Essad ◽  
Bakary Toure

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3517-3517
Author(s):  
Ernesto Perez-Persona ◽  
María-Belén Vidriales ◽  
Gema Mateo ◽  
Ramón Garcia Sanz ◽  
Marivi Mateos ◽  
...  

Abstract Monoclonal Gammopathy of Uncertain Significance (MGUS) is a monoclonal disorder defined by the presence of a serum monoclonal protein <3g/dL, bone marrow plasma cells < 10% and absence of end-organ damage. The risk of progression to multiple myeloma (MM) is about 1% per year, and therefore these patients require long follow-up. Accordingly, the definition of new parameters that could be used for the identification of patients at risk of progression could be of great value. The aim of the present study is to evaluate the utility of multiparameter flow cytometry analysis of bone marrow (BM) plasma cells (PC) for predicting the risk of progression of MGUS patients. From January 1996 to September 2004, bone marrow aspirate samples from 350 patients, who fulfil the criteria of MGUS according to the International Myeloma Working Group criteria, were analysed by multiparametric flow cytometry. A specific gate on PC was performed based on CD138/CD38 expression and FSC/SSC characteristics and PC were immunophenotypically classified as normal (polyclonal) or aberrant (clonal) according to the expression of CD138, CD38, CD45, CD19 and CD56 antigens. Twenty seven patients (8 %) progressed to MM, with a median time to progression (TTP) of 46 months (range 9 to 109 months). Interestingly, the percentage of aberrant PC within the total BM PC compartment (aPC/BMPCc) clearly identify patients at different risk of progression. Thus, TTP in patients with ≥ 95% aPC/BMPCc was 85 months vs not reached cases with <95% aPC/BMPCc (p=0.0000). Other parameters with a significant influence on progression in the univariate analysis were: paraprotein level (higher vs lower of 2 mg/dl; p= 0.0004), the presence of immunoparesis (no paresis vs. decreased levels in one or two Ig. p= 0.0005), Bence-Jones proteinuria (p= 0.0003), PC BM infiltration assessed both by morphology and flow cytometry (p=0.0074; and p= 0.001, respectively), and DNA index assessed by flow cytometry (diploid vs aneuploid; p=0.0064). Moreover, the cut off level of 95% aPC/BMPCc, also allows the discrimination of two risk categories upon considering only patients at low risk of progression, based on a low paraprotein level or absence of inmunoparesis (p= 0.0000 and p= 0.0000, respectively). On multivariate analysis only the percentage of aPC/BMPCc (≥95%) (p=0.000), the DNA index (p=0.007), and the Bence-Jones proteinuria (p=0.000) showed independent prognostic value. In summary, our results show that multiparameter FC evaluation of BMPC at diagnosis is a simple, cost-effective and valuable tool for predicting the risk of progression of MGUS patients.


2001 ◽  
Vol 28 (2) ◽  
pp. 114-116 ◽  
Author(s):  
C. E. Simpson

Abstract The use of wild Arachis L. in cultivar improvement programs has been considered an option for more than 50 yr. Both A. Krapovickas and W.C. Gregory, independently, made interspecific hybridizations in the 1940s. However, only three cultivars have been released as a result of interspecific hybridizations, and only one of those has a clearly identifiable genetic component from the wild species. Several breeding lines have been reported and several germplasm releases are documented from Texas, North Carolina, and ICRISAT. At least four potential options exist for transferring genes from wild Arachis to the cultigen: a) The hexaploid pathway consists of crossing a diploid wild species directly with A. hypogaea, doubling the chromosome number to the hexaploid level, then backcrossing for several generations to restore the tetraploid condition. Several options are possible in this pathway involving various crossing schemes prior to crossing a diploid hybrid with A. hypogaea. North Carolina and ICRISAT have had success with this pathway. b) The diploid/tetraploid pathway has been the most successful in Texas to date. This pathway involves crossing diploid species (two to several), doubling the chromosome number of the hybrid, then crossing to A. hypogaea and backcrossing with selection for the desired character. This pathway is most successful when both A-and B-genome species are involved. Germplasm lines and a cultivar have been released in Texas using this pathway. c) Another diploid/tetraploid pathway could be to double chromosome numbers of diploid species and cross the amphiploids directly with A. hypogaea. Several attempts have been made with this technique, but no germplasm releases have been reported, in large part because sterility is too great when both A and B genomes are not included in the hybrid. Many of the sections/species of wild Arachis are so greatly isolated from A. hypogaea that plant transformation will be the likely method to introduce genes into the cultigen. d) Molecular methods of “inserting” genes into peanut that have been modestly successful and include use of Agrobacterium spp., electroporation, and direct DNA delivery techniques such as the gene gun, whiskers, and sonication. No releases have resulted.


Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1950
Author(s):  
Guadalupe Palomino ◽  
Javier Martínez-Ramón ◽  
Verónica Cepeda-Cornejo ◽  
Miriam Ladd-Otero ◽  
Patricia Romero ◽  
...  

Echeveria is a polyploid genus with a wide diversity of species and morphologies. The number of species registered for Echeveria is approximately 170; many of them are native to Mexico. This genus is of special interest in cytogenetic research because it has a variety of chromosome numbers and ploidy levels. Additionally, there are no studies concerning nuclear DNA content and the extent of endopolyploidy. This work aims to investigate the cytogenetic characteristics of 23 species of Echeveria collected in 9 states of Mexico, analyzing 2n chromosome numbers, ploidy level, nuclear DNA content, and endopolyploidy levels. Chromosome numbers were obtained from root tips. DNA content was obtained from the leaf parenchyma, which was processed according to the two-step protocol with Otto solutions and propidium iodide as fluorochrome, and then analyzed by flow cytometry. From the 23 species of Echeveria analyzed, 16 species lacked previous reports of 2n chromosome numbers. The 2n chromosome numbers found and analyzed in this research for Echeveria species ranged from 24 to 270. The range of 2C nuclear DNA amounts ranged from 1.26 pg in E. catorce to 7.70 pg in E. roseiflora, while the 1C values were 616 Mbp and 753 Mbp, respectively, for the same species. However, differences in the level of endopolyploidy nuclei were found, corresponding to 4 endocycles (8C, 16C, 32C and 64C) in E. olivacea, E. catorce, E. juarezensis and E. perezcalixii. In contrast, E. longiflora presented 3 endocycles (8C, 16C and 32C) and E. roseiflora presented 2 endocycles (8C and 16C). It has been suggested that polyploidization and diploidization processes, together with the presence of endopolyploidy, allowed Echeveria species to adapt and colonize new adverse environments.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 905E-905
Author(s):  
Philipp W. Simon

Genetic improvement of carrot, onion, and garlic has depended upon introgression of alleles from foreign cultivars, from wild forms of cultivated species, and from wild species. Introgression of Asian germplasm in European carrots has resulted in more than a doubling of carotene content; wild carrot has provided two of the most widely used male-sterile cytoplasms for production of hybrids; and Daucus capillifolius has been used as a source of resistance to carrot fly. Onion male-sterile cytoplasm used for hybrid production has its origins in a species related to onion, while resistance to several diseases originated in foreign cultivars. Production of true garlic seed has depended on a broad germplasm base for its success. More examples and germplasm utilization strategies will be discussed.


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