scholarly journals Nuclear DNA Content and Ploidy Level of Apple Cultivars Including Polish ones in Relation to Some Morphological Traits

2016 ◽  
Vol 58 (1) ◽  
pp. 81-93 ◽  
Author(s):  
Małgorzata Podwyszyńska ◽  
Dorota Kruczyńska ◽  
Aleksandra Machlańska ◽  
Barbara Dyki ◽  
Iwona Sowik

Abstract Apple species and cultivars differ in nuclear (2C) DNA content and ploidy level. The majority of these genotypes are diploids, but there are some triploids and a few tetraploids. Nuclear DNA content is a specific feature and its flow cytometric evaluation can be helpful in differentiating taxa. For many apple genotypes – including all the Polish ones, these characteristics are not known. 2C DNA was evaluated in relation to leaf, flower, fruit, pollen grain and stomata sizes as well as to the flowering time for seventy genotypes (including 46 Polish cultivars) gathered in the gene bank of the Research Institute of Horticulture, Skierniewice, Poland. For standard cultivars with the known chromosome number, 2C value was 1.71 pg for diploid cultivar ‘Alwa’ (2n=2x=34), 2.55 pg for triploid ‘Boskoop’ (3x=51), and 3.37 pg for tetraploid genome (4x=68) of mixoploid ‘McIntosh 2x+4x’. In 61 cultivars (including 41 Polish ones), the nuclear DNA content ranged from 1.58 to 1.78 pg indicating their diploid chromosome number. Five cultivars were identified as triploids (‘Bursztówka Polska’, ‘Pagacz’, ‘Rapa Zielona’, ‘Rarytas Śląski’ and ‘Witos’) owing to their nuclear DNA amount ranging between 2.42 and 2.58 pg. Leaf, flower, fruit, stomata and pollen grain sizes were on average significantly larger in triploids. Thus, in 3x plants the mean leaf surface was 49.1 cm2, flower diameter – 52.4 mm, fruit weight – 204.7 g, stomata length – 32.1 μm and pollen grain diameter – 33.7 μm, whereas in diploids – 36.0 cm2, 46.1 mm, 162.7 g, 28.4 μm and 30.7 μm, respectively. Pollen grain viability was on average significantly higher in diploids (75.6%), compared to triploids (22%). These results confirm that in apple, as in many other plant species, the higher ploidy level of triploids is generally associated with increased sizes of pollen grains, stomata, flowers, fruits and leaves but decreased pollen viability. No clear correlation between ploidy level and flowering time was found. In the case of mixoploid apple genotypes possessing diploid and tetraploid genomes, some phenotype observation is helpful in describing the ploidy level of the histogenic layers, L1 and L2. Small stomata sizes (similar to diploid) indicate diploid L1 and larger leaf sizes, compared to diploid counterparts, show tetraploid L2. The results will be used for breeding, in which it is important to determine maternal and paternal genotypes as well as the direction of the crossing that is of great importance in obtaining seeds and materials for further selection.

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 ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 627b-627
Author(s):  
Peter H. Velguth ◽  
Harold Pellett

We evaluated flow cytometric measurement of nuclear DNA content to determine ploidy level in azalea. If ploidy level correlates with DNA content, ploidy level could be determined more readily than by direct chromosome counts and assist in planning crosses and evaluating progeny. Tested plants included azalea cultivars, materials from the azalea breeding project at the Univ. of Minnesota, and species from the Rhododendron Species Botanic Garden and the North Carolina Arboretum. Data compiled from DNA assays of practically all material analyzed fell into distinct groups consistent with their being either diploid, triploid, or tetraploid. Additionally, a known diploid plant of each of four diploid species, together with a natural or derived tetraploid plant of each of these species was obtained. Results showed that the four diploids had a similar DNA content compared to one another. DNA content of the tetraploids was also similar, and the tetraploid's DNA content was approximately twice that of the diploids, as expected. Unfortunately, success with direct chromosome counts in other material has proven elusive, currently precluding direct correlation of DNA amount with ploidy level across other species and cultivars. Although many cases exist in the literature where DNA content has a direct relationship to ploidy level, this does not always hold. Although the majority of plants tested fell into a diploid, triploid, or tetraploid grouping based on DNA content, further study is required to determine the exact relationship between ploidy level and DNA content in azalea.


Genome ◽  
1990 ◽  
Vol 33 (1) ◽  
pp. 143-147 ◽  
Author(s):  
Jayanti Sen ◽  
Sumona Mukherjee ◽  
A. K. Sharma

Cells of six different species of Luzula were subjected to in vitro culture and examined for callus formation. The cells of calli from the different species were analyzed for variation in chromosome number. The cells of different species showed a differential response in culture with respect to callus growth. Chromosome number variation in vitro, including both hypo- and hyper-diploidy, was recorded in all species except L. pediformis and L. luzuloides. The chromosome fragments survived as a result of a nonlocalized centromere. With prolonged culture, normal diploid cells were frequent. The nuclear DNA content of cells of these species was also measured, both in vivo and in vitro. The DNA values ranged from 6.05 to 7.03 pg per 4C nucleus. No marked change in DNA value was noted in cells even with high chromosome numbers, thereby confirming their origin through fragmentation of chromosomes. In cells of callus, the DNA amount was observed to be higher than in normal cells, indicating fragmentation and duplication of individual chromosomes. Their importance in the origin of new genotypes has been indicated.Key words: Luzula spp., in vitro growth, chromosomes, nuclear DNA content.


2017 ◽  
Vol 17 (4) ◽  
pp. 320-326 ◽  
Author(s):  
Luis Felipe Lima e Silva ◽  
Vânia Helena Techio ◽  
Luciane Vilela Resende ◽  
Guilherme Tomaz Braz ◽  
Kátia Ferreira Marques de Resende ◽  
...  

2011 ◽  
Vol 83 (3) ◽  
pp. 993-1006 ◽  
Author(s):  
Patrícia M.O. Pierre ◽  
Saulo M. Sousa ◽  
Lisete C. Davide ◽  
Marco A. Machado ◽  
Lyderson F. Viccini

Cytogenetic analyses, of pollen viability, nuclear DNA content and RAPD markers were employed to study three chemotypes of Lippia alba (Mill.) (Verbenaceae) in order to understand the genetic variation among them. Different ploidy levels and mixoploid individuals were observed. This work comprises the first report of different chromosome numbers (cytotypes) in L. alba. The chromosome numbers of La2-carvone and La3-linalool chemotypes suggested that they are polyploids. Flow cytometric analysis showed an increase of nuclear DNA content that was not directly proportional to ploidy level variation. A cluster analysis based on RAPD markers revealed that La3-linalool shares genetic markers with La1-citral and La2-carvone. The analysis showed that the majority of genetic variation of La3-linalool could be a consequence of ixoploidy. ur data indicates that sexual reproduction aong those three chemotypes is unlikely and suggests the beginning of reproductive isolation. The results demonstrated that chromosome analysis, nuclear DNA content estimation and RAPD markers constitute excellent tools for detecting genetic variation among L. alba chemotypes.


1998 ◽  
Vol 76 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Jérôme Thibault

Flow cytometry (FCM) has been used to estimate the nuclear DNA content of 11 Salix species and 5 hybrids. One hundred and sixty nine individuals were studied including 159 individuals from a sequence of 32 communities along a stretch of river in France and 10 individuals from French and English collections for comparison. Isolated nuclei were stained with propidium iodide. FCM was a significantly more practical and rapid technique than that of establishing the karyotype to survey many samples of Salix for variation in ploidy. The 2C DNA amounts for diploid species ranged from 0.76 to 0.98 pg, and tetraploid values ranged from 1.62 to 1.80 pg. The DNA values were consistent with the known ploidy levels. With the exception of a doubtful Salix xquercifolia, ploidy levels and DNA amounts of hybrids were intermediate compared with those of their parents. Intraspecific variation of nuclear DNA values including instrumental variation was low (i.e., 6-11% at the same ploidy level). FCM appeared to be an accurate tool for determination of Salix triploid hybrids. However, it remains limited concerning hybrids from crosses between species of the same ploidy level. Results suggest that natural hybridization might not be frequent in the communities studied, although they have been subject to disturbance. Previous overestimates of hybridization frequency in willows were probably due to misinterpretation of the effects of the environment on Salix spp. morphology; however, the extent and mechanisms of introgression in the genus remain to be further investigated. Key words: flow cytometry, Salix, hybridization, nuclear DNA content, riparian vegetation, disturbance.


Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 659-662 ◽  
Author(s):  
H. L. Porter ◽  
A. Lane Rayburn

The B-chromosome and C-band numbers were determined in 12 Arizona Indian maize populations. These populations were originally collected from altitudes ranging from 100 to 5300 ft (1 ft = 0.3048 m). In addition, the total nuclear DNA amounts of these populations have been observed to vary by as much as 20%. The number of B-chromosomes was not significantly correlated with altitude, C-band number, or nuclear DNA amount. C-band number was significantly correlated with both altitude and genome size. It does not appear that the amount of C-band variation can account for the large nuclear DNA variation observed in these accessions. Additional A-chromosomal DNA sequences may be involved in the nuclear DNA content variation that exists among these accessions.Key words: heterochromatin, DNA content, evolution, repeated DNA.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 580e-580
Author(s):  
Rodomiro Ortiz ◽  
D.E. Costich ◽  
T.P. Meagher ◽  
N. Vorsa

DNA flow cytometry was used to determine nuclear DNA content in diploid blueberry species, and 3x, 4x, 5x, and 6x ploidy levels. Relative fluorescence intensity of stained nuclei measured by flow cytometry was a function of the number of chromosome sets (X): Y = 3.7X – 2.3 (r2 = 95.1%). DNA flow cytometry should be useful for ploidy level determination in the seedling stage. A significant linear relationship was established between nuclear DNA content and number of chromosomes (x); DNA (pg) = 0.52 x1 (r2 = 99.8%). Based on this equation the haploid genome DNA amount (1C) was calculated as 0.62 ± 0.08 pg, with an approximate haploid genome size of 602 Mbp/1C. The results indicate that conventional polyploid evolution occured in the section Cyanococcus, genus Vaccinium: the increase in DNA was concurrent with increase in chromosome number. DNA content differences among 2x species were correlated with Nei's genetic distance estimates based on 20 isozyme markers. Most of the variation was among species (49%), with 26% between populations within species, and 25% within populations.


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