scholarly journals Nuclear DNA endoreplication and plastid index in mesophyll of some dicotyledonous species

2014 ◽  
Vol 57 (3) ◽  
pp. 303-316 ◽  
Author(s):  
Barbara Damsz ◽  
Piotr Łuchniak

Cytophotometric studies of nuclear DNA content after Feulgen procedure indicate that in mesophyll of all the seven studied species the highest nuclear DNA endoreplication level occurs in II or III leaf and it varies for particular species. No differences were found in nuclear DNA endoreplication dynamics between the basal and apical parts of the leaf blade. Chloroplast number per cell generally decreases in the successive leaves, and the plastid index is the smallest in the first (oldest) leaves, being similar in both zones. In four species chloroplast number and plastid index show relatively low negative correlation with nuclear DNA contents (expressed as endoreplication index), in two species this correlation is positive, and one species displays very low r value.

2009 ◽  
Vol 57 (6) ◽  
pp. 524 ◽  
Author(s):  
Milene Miranda Praça ◽  
Carlos Roberto Carvalho ◽  
Carolina Ribeiro Diniz Boaventura Novaes

Previous flow cytometry (FCM) analyses delivered nearly equal mean values of nuclear 2C DNA content for Eucalyptus grandis Hill ex Maiden and E. urophylla S. T. Blake (1.33 pg and 1.34 pg, respectively), whereas E. globulus Labill. presented distinct mean values (1.09, 1.13 and 1.40). These differences have been attributed to the different methodological approach, utilised plant cultivar and presence of intrinsic metabolic compounds that affect fluorochrome fluorescence. In the present study, a FCM and image cytometry (ICM) design, following international consensus criteria, were adopted to reassess the nuclear DNA contents of the above-mentioned Eucalyptus species. Statistical analyses revealed either similar or discrepant nuclear DNA contents, depending on the standard species used and whether FCM or ICM was employed. Our results demonstrated that 2C DNA values obtained by FCM and ICM were most uniform when Solanum lycopersicum was used as a standard. Moreover, the values obtained for E. grandis and E. urophylla were close, but differed as much as 24.63% in relation to previous data, and E. globulus proportionally varied up to 25%. New DNA content values are suggested for these eucalypt species.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
B. J. M. Zonneveld

Genome size (C-value) was applied anew to investigate the relationships within the genus Hepatica (Ranunculaceae). More than 50 samples representing all species (except H. falconeri), from wild and cultivated material, were investigated. Species of Hepatica turn out to be diploid (), tetraploid ( ), and a possible pentaploid. The somatic nuclear DNA contents (2C-value), as measured by flow cytometry with propidium iodide, were shown to range from 33 to 80 pg. The Asiatic and American species, often considered subspecies of H. nobilis, could be clearly distinguished from European H. nobilis. DNA content confirmed the close relationships in the Asiatic species, and these are here considered as subspecies of H. asiatica. Parents for the allotetraploid species could be suggested based on their nuclear DNA content. Contrary to the increase in genome size suggested earlier for Hepatica, a significant (6%–14%) loss of nuclear DNA in the natural allopolyploids was found.


1971 ◽  
Vol 13 (3) ◽  
pp. 607-611 ◽  
Author(s):  
Michael D. Bennett ◽  
J. B. Smith

The 4C nuclear DNA content was estimated for 17 wild Hordeum species and five cultivated Hordeum vulgare varieties which were chosen to include examples varying greatly in geographical origin and in morphological and physiological characters. Nuclear DNA was measured on an integrating microdensitometer using prophase nuclei in Feulgen stained root-tip squashes. There were no significant differences in DNA content between any or the 15 diploid genotypes measured, and the seven polyploid genotypes all had nuclear DNA contents which were simple multiples of the diploid genotypes. This result, namely that the DNA content of diploid Hordeum species is invariable, differs from results obtained from diploid species in several other plant genera which differed greatly in nuclear DNA content.


1985 ◽  
Vol 27 (1) ◽  
pp. 47-50 ◽  
Author(s):  
J. B. Anderson ◽  
D. M. Petsche ◽  
A. L. Franklin

The relative nuclear DNA contents of haploid, diploid, and benomyl-induced segregants of diploid strains of the phytopathogenic fungus Armillaria mellea were measured by mithramycin staining and fluorescence photometry. The diploid strains, originally recovered from sexually compatible matings of haploid strains, were heterozygous at mating-type and auxotrophic marker loci. The somatic segregants examined here were derived by treatment of the diploid strains with the fungicide benomyl in previous studies. As expected, the diploid strains had approximately twice as much nuclear DNA as the haploid strains. Most segregants had near-haploid DNA contents and no detectable heterozygosity at the marker loci; these strains were most likely true haploids. Other segregants with near-haploid DNA contents were heterozygous at a marker locus indicating that they were aneuploid. A minority of segregants had near-diploid DNA contents and may have been either aneuploid or diploid.Key words: basidiomycetes, mithramycin, parasexuality.


2001 ◽  
Vol 126 (2) ◽  
pp. 195-199 ◽  
Author(s):  
Sandy Lin ◽  
Hsiao-Ching Lee ◽  
Wen-Huei Chen ◽  
Chi-Chang Chen ◽  
Yen-Yu Kao ◽  
...  

Nuclear DNA contents were estimated by flow cytometry in 18 Phalaenopsis Blume species and Doritis pulcherrima Lindl. DNA amounts differed 6.07-fold, from 2.74 pg/diploid nuclear DNA content (2C) in P. sanderiana Rchb.f. to 16.61 pg/2C in P. parishii Rchb.f. Nuclear DNA contents of P. aphrodite Rchb.f. clones, W01-38 (2n = 2x = 38), W01-41 (2n = 3x = 57), and W01-22 (2n = 4x = 76), displayed a linear relationship with their chromosome numbers, indicating the accuracy of flow cytometry. Our results also suggest that the 2C-values of the Phalaenopsis sp. correlate with their chromosome sizes. The comparative analyses of DNA contents may provide information to molecular geneticists and systematists for genome analysis in Phalaenopsis. Endoreduplication was found in various tissues of P. equestris at different levels. The highest degree of endoreduplication in P. equestris was detected in leaves.


2008 ◽  
Vol 90 (1) ◽  
pp. 111-118 ◽  
Author(s):  
THOMAS R. MEAGHER ◽  
DENISE E. COSTICH

SummaryOne of the long-standing mysteries in genomic evolution is the observation that much of the genome is composed of repetitive DNA, resulting in inter- and intraspecific variation in nuclear DNA content. Our discovery of a negative correlation between nuclear DNA content and flower size in Silene latifolia has been supported by our subsequent investigation of changes in DNA content as a correlated response to selection on flower size. Moreover, we have observed a similar trend across a range of related dioecious species in Silene sect. Elisanthe. Given the presence of sex chromosomes in dioecious Silene species, and the tendency of sex chromosomes to accumulate repetitive DNA, it seems plausible that dioecious species undergo genomic evolution in ways that differ from what one might expect in hermaphroditic species. Specifically, we query whether the observed relationship between nuclear DNA content and flower size observed in dioecious Silene is a peculiarity of sex chromosome evolution. In the present study we investigated nuclear DNA content and flower size variation in hermaphroditic species of Silene sect. Siphonomorpha, as close relatives of the dioecious species studied previously. Although the nuclear DNA contents of these species were lower than those for species in sect. Elisanthe, there was still significant intra- as well as interspecific variation in nuclear DNA content. Flower size variation was found among species of sect. Siphonomorpha for petal claw and petal limb lengths, but not for calyx diameter. This last trait varies extensively in sect. Elisanthe, in part due to sex-specific selection. A negative correlation with nuclear DNA content was found across populations for petal limb length, but not for other floral dimensions. We conclude that impacts of nuclear DNA content on phenotypic evolution do manifest themselves in hermaphroditic species, so that the effects observed in sect. Elisanthe, and particularly in S. latifolia, while perhaps amplified by the genomic impacts of sex chromosomes, are not limited to dioecious taxa.


A survey of work on meiotic duration in diploid plants shows that the duration is positively correlated with the DNA content per nucleus and with the mitotic cycle time. However, meiotic duration is not solely determined by the DNA content per nucleus but is also affected by chromosomal organization, DNA structure and the developmental pattern of the organism. Thus, in three polyploid plant species meiosis is much shorter and in three animal species it is much longer than would be expected in diploid plant species having corresponding DNA contents. Differences in meiotic duration in plant species are usually the result of proportional differences in all the stages of meiosis. Factors affecting the initiation, control and duration of meiosis are discussed. The consequences of changes in nuclear DNA content on developmental processes and the life cycle in plants are considered. It is suggested that DNA influences development in two ways, first directly through its informational content, and second indirectly by the physical mechanical effects of its mass independent of its informational content.


AoB Plants ◽  
2011 ◽  
Vol 2011 ◽  
Author(s):  
Naomi Phillips ◽  
Donald F. Kapraun ◽  
Amelia Gómez Garreta ◽  
M. Antonia Ribera Siguan ◽  
Jorde L. Rull ◽  
...  

Abstract Background and aims Brown algae are critical components of marine ecosystems around the world. However, the genome of only one species of the class has so far been sequenced. This contrasts with numerous sequences available for model organisms such as higher plants, flies or worms. The present communication expands our coverage of DNA content information to 98 species of brown algae with a view to facilitating further genomic investigations of the class. Methodology The DNA-localizing fluorochrome DAPI (4′,6-diamidino-2-phenylindole) and the red blood cell (chicken erythrocyte) standard were used to estimate 2C values by static microspectrophotometry. Principal results 2C DNA contents are reported for 98 species of brown algae, almost doubling the number of estimates available for the class. The present results also expand the reported DNA content range to 0.2–3.6 pg, with several species of Fucales and Laminariales containing apparent polyploid genomes with 2C = 1.8–3.6 pg. Conclusions The data provide DNA content values for 12 of the 19 recognized orders of brown algae spanning the breadth of the class. Despite earlier contentions concerning DNA content and the presence of oogamy, the present results do not support a correlation between phylogenetic placement and genome size. The closest sister groups to the brown algae have genome sizes on the order of 0.3 pg (e.g. Schizocladiophyceae), suggesting that this may be the ancestral genome size. However, DNA content ranges widely across the class.


2014 ◽  
Vol 71 (3) ◽  
pp. 195-200
Author(s):  
Hanna Kuran ◽  
Kazimierz Marciniak

Mitotic activity and nuclear DNA content in endosperm of <em>Zea mays</em> cv. Złota Karłowa were examined. DNA content was cytophotometrically measured on squashed preparations after Feulgen procedure. Mitotic activity in endosperm was determined till the stage when embryo sack reached 4.5 mm in length. Some of mitotic figures show multiplied DNA content. Endosperm nuclei have various DNA contents which increase throughout endosperm development. DNA content enhancement indicates endoreduplication in progress. Some nuclei with high DNA content display changes in chromatin structure, which are expressed by the presence of strands and aggregates of chromatin characterised by high staining intensity. A conclusion has been drawn that mitotic divisions and the endoreduplication phase of nuclear DNA may occur simultaneously and dominate one over another at different phases of endosperm development.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1339
Author(s):  
Piotr Kamiński ◽  
Agnieszka Marasek-Ciolakowska ◽  
Małgorzata Podwyszyńska ◽  
Michał Starzycki ◽  
Elżbieta Starzycka-Korbas ◽  
...  

Interspecific hybridization between B. oleracea inbred lines of head cabbage, Brussels sprouts, kale and B. taurica and inbred lines of rapeseed (B. napus L.) were performed aiming at the development of the new sources of genetic variability of vegetable Brassicas. Using conventional crossings and the embryo-rescue techniques the following interspecific hybrids were developed: 11 genotypes of F1 generation, 18 genotypes of F2 and F1 × F2 generations (produced after self- and cross-pollination of interspecific F1 hybrids), 10 plants of the BC1 generation (resulted from crossing head cabbage cytoplasmic male-sterile lines with interspecific hybrids of the F2 and F1 generations) and 8 plants of BC1 × (F1 × F2). No viable seeds of the BC2 generation (B. oleracea) were obtained due to the strong incompatibility and high mortality of embryos. The morphological characteristics during the vegetative and generative stages, pollen characteristics, seed development and propagation, nuclear DNA contents and genome compositions of interspecific hybrids were analyzed. All the interspecific F1 hybrids were male-fertile with a majority of undeveloped and malformed pollen grains. They showed intermediate values for morphological traits and nuclear DNA contents and had nearly triploid chromosomal numbers (27 to 29) compared with parental lines. The F2 generation had a doubled nuclear DNA content, with 52 and 56 chromosomes, indicating their allohexaploid nature. F2 hybrids were characterized by a high heterosis of morphological characteristics, viable pollen and good seed development. F1 × F2 hybrids were male-fertile with a diversified DNA content and intermediate pollen viability. BC1 plants were male-sterile with an intermediate nuclear DNA content between the F2 and head cabbage, having 28 to 38 chromosomes. Plants of the BC1 × (F1 × F2) generation were in majority male-fertile with 38–46 chromosomes, high seed set, high heterosis and intermediate values for morphological traits. The obtained interspecific hybrids are valuable as new germplasm for improving Brassica-breeding programs.


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