Differences in Winter Browning among Japanese-cedar Cultivars Are Not Due to Variation in Ploidy Levels

There is a great deal of variation among japanese-cedar cultivars with regard to growth form, foliar characteristics, and winter browning. Differences in winter browning have been observed and documented by a number of authors. Previous research has established that there are differences in winter foliage color between cultivars included in the current study; however, no quantitative analysis under standardized conditions was conducted. Because of a previous report that tetraploid forms of japanese-cedar remain green during winter as a result of increased antioxidant enzyme activity, we hypothesized that cultivars that exhibit reduced winter browning were polyploids. We screened 56 accessions of japanese-cedar using flow cytometry analysis of 4′,6-diamidino-2-phenylindole (DAPI)-stained nuclei and performed chromosome counts on three cultivars. All accessions were diploid (2n = 2x = 22), although there were significant differences in genome sizes among the cultivars. Holoploid genome sizes ranged from 18.9 pg for var. sinensis JCRA to 22.3 pg for ‘Viridis’ with a mean of 20.1 pg. Chromosome counts for cultivars Ogon, Oye Keme, and Viridis supported the flow cytometry results. Although the underlying cause of the variability in morphology and winter browning among cultivars is unclear, our results show that differences in ploidy level are not responsible, because all tested genotypes were diploid. Chemical name: 4′,6-diamidino-2-phenylindole (DAPI).

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MICROPROPAGATION AND PLOIDY STABILITY OF Lippia lacunosa Mart. & Schauer: AN ENDANGERED BRAZILIAN MEDICINAL PLANT

JOURNAL OF NEOTROPICAL AGRICULTURE ◽

10.32404/rean.v6i1.3203 ◽

2019 ◽

Vol 6 (1) ◽

pp. 1-7

Author(s):

Diego Pandeló José ◽

José Marcello Salabert De Campos ◽

Lyderson Facio Viccini ◽

Emilly Ruas Alkimim ◽

Marcelo De Oliveira Santos

Keyword(s):

Flow Cytometry ◽

Medicinal Plant ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Naphthalene Acetic Acid ◽

Flow Cytometry Analysis ◽

Ploidy Levels

Lippia lacunosa is a Brazilian savanna plant that belongs to the Verbenaceae family. It has been used in folk medicine as a treatment for different diseases. This species represents an endangered Brazilian medicinal plant, and this is the first report documenting a reliable protocol for the in vitro propagation and regeneration of L. lacunosa. Axenic explants were cultivated in MS medium containing different concentrations of naphthalene acetic acid (NAA) to induce root growth. The mean shoot length and the number of roots were highest with 0.06 mg·L-1 NAA. The highest number of buds in shoot regeneration was induced with 2 mg·L-1 6-benzylaminopurine (BA). To obtain a long-term culture, the dwarf shoots were elongated on MS media containing 0.5 mg·L-1 BA alternated with MS containing 2 mg·L-1 BA every 40 days. In the present protocol, the long-term shoots retained the ability to root even after long periods of BA treatment. In addition, we evaluated the nuclear DNA content and ploidy levels, including the occurrence of endopolyploidy, in long-term micropropagated plant leaves using flow cytometry analysis. The plants propagated in vitro over several years possessed nuclear DNA contents ranging from 2.940 to 3.095 pg, and no differences in DNA content were found among in vitro plants or between these plants and the control (L. lacunosa from a greenhouse with a DNA content of 3.08 pg). The flow cytometry analysis also demonstrated that there was no polyploidization. The present study will be useful for biotechnological approaches and provides the first estimate of the nuclear DNA content of this species using flow cytometry.

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Oryzalin-induced Tetraploidy in Cryptomeria japonica (Cupressaceae)

HortScience ◽

10.21273/hortsci.45.2.316 ◽

2010 ◽

Vol 45 (2) ◽

pp. 316-319 ◽

Cited By ~ 2

Author(s):

Ryan N. Contreras ◽

John M. Ruter ◽

Brian M. Schwartz

Keyword(s):

Flow Cytometry ◽

Environmental Conditions ◽

Cryptomeria Japonica ◽

Japanese Cedar ◽

Phenotypic Marker ◽

Ploidy Levels ◽

Random Subset ◽

Laboratory Conditions

Japanese-cedar [Cryptomeria japonica (L.f.) D. Don] represents an alternative to leyland cypress [×Cuprocyparis leylandii (A.B. Jacks. & Dallim.) Farjon] as an evergreen screen or specimen plant for landscapes. It performs well under a range of soil and environmental conditions but has been underused attributable, in part, to unsightly winter browning caused by photoinhibition. In previous studies, chance seedlings that did not exhibit winter browning were identified as tetraploids. The current study was conducted to induce polyploidy in japanese-cedar. Approximately 600 seedlings were sprayed with 150 μM oryzalin + 0.1% SilEnergy™ for 30 consecutive days under laboratory conditions. Two hundred thirty-seven seedlings with thickened and twisted leaves were selected, transplanted, and grown in a glasshouse for 120 days. Seedling ploidy levels were analyzed using flow cytometry 180 days after treatment (DAT), identifying 197 (83.1%) tetraploids, 22 (9.3%) cytochimeras, and 18 (7.6%) diploids. Morphology of induced tetraploids was similar to that previously described and provided a phenotypic marker during selection that was over 92% accurate. A random subset of 20 tetraploid individuals was analyzed 270 DAT and were found to contain only tetraploid cells in the leaves analyzed, confirming stability over this period. This study demonstrated the use of oryzalin for inducing tetraploids in japanese-cedar, which we predict will be effective in other gymnosperms.

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Genome Size Estimates and Chromosome Numbers of Callicarpa L. (Lamiaceae)

HortScience ◽

10.21273/hortsci.46.4.567 ◽

2011 ◽

Vol 46 (4) ◽

pp. 567-570 ◽

Cited By ~ 2

Author(s):

Ryan N. Contreras ◽

John M. Ruter

Keyword(s):

Flow Cytometry ◽

Chromosome Number ◽

Genome Size ◽

Chromosome Numbers ◽

Chromosome Counts ◽

Ploidy Levels ◽

Flow Cytometry Data ◽

Carbol Fuchsin ◽

Cross Compatibility ◽

Size Estimates

Genome size estimates and chromosome number information can be useful for studying the evolution or taxonomy of a group and also can be useful for plant breeders in predicting cross-compatibility. Callicarpa L. is a group of ≈140 species with nearly worldwide distribution. There are no estimates of genome size in the literature and the information on chromosome numbers is limited. Genome size estimates based on flow cytometry are reported here for 16 accessions of Callicarpa comprising 14 species in addition to chromosome counts on six species. Chromosome counts were conducted by staining meristematic cells of roots tips using modified carbol fuchsin. Holoploid genome size estimates ranged from 1.34 pg to 3.48 pg with a mean of 1.74 pg. Two tetraploids (2n = 4x = 68; C. salicifolia P'ei & W. Z. Fang and C. macrophylla Vahl GEN09-0081) were identified based on holoploid genome size and confirmed by chromosome counts. There was little variation among species for monoploid genome size. 1Cx-values ranged from 0.67 pg to 0.88 pg with a mean of 0.77 pg. Chromosome counts for six species revealed a base chromosome number of x = 17. Callicarpa chejuensis Y. H. Chung & H. Kim, C. japonica Thunb. ‘Leucocarpa’, C. longissima Merr., and C. rubella Lindl. were confirmed as diploids (2n = 2x = 34). Cytology supported flow cytometry data that C. salicifolia and C. macrophylla GEN09-0081 were tetraploids. The two accessions of C. macrophylla included in the study were found to be of different ploidy levels. The presence of two ploidy levels among and within species indicates that polyploidization events have occurred in the genus.

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Characterizing polyploidy in Arabidopsis lyrata using chromosome counts and flow cytometry

Canadian Journal of Botany ◽

10.1139/b03-134 ◽

2004 ◽

Vol 82 (2) ◽

pp. 185-197 ◽

Cited By ~ 49

Author(s):

Sara Dart ◽

Paul Kron ◽

Barbara K Mable

Keyword(s):

Flow Cytometry ◽

North America ◽

Dna Content ◽

Geographic Range ◽

Chromosome Counts ◽

Dynamic Nature ◽

Ploidy Levels ◽

Arabidopsis Lyrata ◽

Genomic Changes ◽

European Populations

Protocols were developed for both chromosome counts and flow cytometry to assess ploidy level and DNA content for populations of Arabidopsis lyrata L. sampled from Europe (Arabidopsis lyrata subsp. petraea), North America (Arabidopsis lyrata subsp. lyrata), and Japan (Arabidopsis lyrata subsp. kawasakiana). Ploidy variation within this species is not clear, with previous studies having documented both diploid and tetraploid populations. Chromosome counts in this study confirmed ploidy expectations for all populations examined. Individuals from Iceland and North America were diploid (2n = 2x = 16), whereas those from Japanese and Austrian populations were tetraploid (2n = 4x = 32). Flow cytometry was also used successfully to distinguish between ploidy levels, but the need to calibrate DNA content measures with chromosome counts was demonstrated by a deviation from the expected 2:1 ratio between tetraploid and diploid values among European populations (A. lyrata subsp. petraea). This deviation might be explained by a hybrid (allopolyploid) origin or by genomic changes following polyploidization, emphasizing the dynamic nature of polyploid genomes. Variation in DNA content among families was found only for North American populations, but these individuals were sampled from a broader geographic range than those from other regions.Key words: cytogenetics, flow cytometry, polyploidy, Arabidopsis lyrata, genome size, chromosome counts.

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