Crossability, Cytogenetics, and Reproductive Pathways in Rudbeckia Subgenus Rudbeckia

Rudbeckia L. are valuable nursery crops that offer broad adaptability and exceptional ornamental merit. However, there is little information on interspecific and interploid crossability and ploidy levels of specific cultivars. The objectives of this study were to determine the ploidy levels and relative DNA contents (genome sizes) of selected species and cultivars, to evaluate self-compatibility and crossability among species and ploidy levels, and to explore reproductive pathways in triploid R. hirta L. with the goal of facilitating future breeding endeavors and development of new hybrids. Reciprocal interspecific crosses were performed between R. hirta cultivars and R. fulgida Ait., R. missouriensis Engelm. ex C.L. Boynton & Beadle, and R. subtomentosa Pursh. as well as reciprocal interploid crosses among four R. hirta cultivars. A combination of relative DNA content analysis and chromosome counts was used to test for hybridity and to determine ploidy levels for selected species, cultivars, and interploid R. hirta F1 hybrids. Of the specific clones tested, R. subtomentosa and R. missouriensis were diploid, R. fuligida varieties were tetraploid, and R. hirta include both diploid and tetraploid cultivars. Mean 1Cx DNA content varied over 320% among species. The interploid R. hirta crosses produced triploids as well as pentaploids and hexaploids. Seedlings from open-pollinated triploid R. hirta appeared, based on diverse phenotypes and DNA contents, to be aneuploids resulting from sexual fertilization, not apomixis. Of the 844 seedlings from interspecific F1 crosses, only one individual, R. subtomentosa ×R. hirta, had a DNA content intermediate between its parents and was confirmed as the only interspecific hybrid. Although most taxa had low self-fertility, seedlings (with genomic sizes similar to their maternal parent) resulted after interspecific crosspollination, indicating that pseudogamy is one reproductive pathway in Rudbeckia species.

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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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Estimation of relative DNA content in nuclei of races of Phytophthora megasperma f. sp. glycinea by quantitative fluorescence microscopy

Canadian Journal of Genetics and Cytology ◽

10.1139/g85-091 ◽

1985 ◽

Vol 27 (5) ◽

pp. 614-616 ◽

Cited By ~ 10

Author(s):

F. S. Rutherford ◽

E. W. B. Ward

Keyword(s):

Fluorescence Microscopy ◽

Aspergillus Nidulans ◽

Dna Content ◽

Nuclear Dna ◽

Phytophthora Megasperma ◽

Dna Contents ◽

Relative Dna Content ◽

Quantitative Fluorescence

The fluorochrome 4,6-diamidino-2-phenylindole was used as a stain for nuclear DNA in the fungus Phytophthora megasperma f. sp. glycinea. Measurements of DNA contents were made cytofluorometrically using known haploid and diploid strains of Aspergillus nidulans as standards. No significant differences between DNA levels in nine races of Phytophthora megasperma f. sp. glycinea were found. The results are consistent with genetical data that all nine races are diploid in the vegetative state.Key words: Phytophthora, ploidy, fungi, DNA content, fluorescence.

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Flow Sitometri ile Bazı Ispanak Aksesyonlarının Çekirdek DNA İçeriklerinin Belirlenmesi

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v6i2.239-246.1718 ◽

2018 ◽

Vol 6 (2) ◽

pp. 239

Author(s):

Murat Deveci ◽

Özcan Yavaş ◽

Nihan Sahin ◽

Metin Tuna

Keyword(s):

Dna Content ◽

Clustering Analysis ◽

Mitotic Chromosome ◽

Nuclear Dna ◽

Spinacia Oleracea ◽

Ploidy Levels ◽

Spinacia Oleracea L ◽

Multiple Comparison Test ◽

Dna Contents ◽

The Mean

The aim of this research is to determine ploidy levels of 53 spinach (Spinacia oleracea L.) accessions obtained from abroad sources by using flow cytometry. According to the results of the statistical analysis, the differences among DNA content of accessions were statistically important. The average DNA content of spinach accessions used in the study ranged between 2.225 pg/2C (Esfenaj accession) and 2.059 pg/2C (Matador and Godir accessions). The mean nuclear DNA of accessions shown to be relatively stable due to low standard deviation (0.003-0.096). Based on the mitotic chromosome analyses of the some plants with different DNA contents, mitotic chromosome number of the all plants analyzed in the study were determined as 2n=12. These results indicate that all the accessions used in the study are diploid although their DNA content is significantly vary. According to the clustering analysis of the 2C DNA contents results, it was observed that eight sub clusters were formed under two main clusters. The clustering of axioms was performed in a similar manner to the multiple comparison test. As a result, the data will save time and labor convenience in a further breeding studies deal with the same 53 spinach accessions of our study.

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FEULGEN HYDROLYSIS: EFFECT OF ACID AND TEMPERATURE

Journal of Histochemistry & Cytochemistry ◽

10.1177/14.8.601 ◽

1966 ◽

Vol 14 (8) ◽

pp. 601-604 ◽

Cited By ~ 113

Author(s):

JEROME J. DECOSSE ◽

NANCY AIELLO

Keyword(s):

Dna Content ◽

Room Temperature ◽

Human Lymphocytes ◽

Initial Experiment ◽

Optimum Time ◽

Reliable Technique ◽

Dna Contents ◽

Normal Human ◽

Relative Dna Content

Two methods of Feulgen hydrolysis (5.0 N HCl at room temperature and 1.0. N HCl at 60°C) were examined by serial microspectrophotometric measurements of the relative DNA content of normal human lymphocytes subjected to each hydrolysis. The DNA contents at optimum hydrolysis were equal by both methods. Hydrolysis in 5.0 N HCl at room temperature resulted in an interval of 120 min of stable peak values. Successive hydrolyses to the optimum time, as defined for each methtod in the initial experiment, indicated that hydrolysis 5.0. N HCl at room temperature provided a more reliable technique. The results also suggested that depurination is dependent primarily on acid rather than heat, while further degradation is dependent primarily on heat rather than acid.

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QUANTITATIVE VARIATION IN DNA AS RELATED TO PLOIDY LEVEL AND SPECIES IN SOME WILD ROSES

Canadian Journal of Genetics and Cytology ◽

10.1139/g72-043 ◽

1972 ◽

Vol 14 (2) ◽

pp. 347-351 ◽

Cited By ~ 5

Author(s):

M. H. El-Lakany

Keyword(s):

Chromosome Number ◽

Ploidy Level ◽

Dna Content ◽

Diploid Species ◽

Quantitative Variation ◽

Chromosome Behaviour ◽

Interspecific Relationships ◽

Hexaploid Species ◽

Dna Contents ◽

Relative Dna Content

Relative DNA content and chromosome number and behaviour were studied in Manitoba wild roses. The hexaploid, Rosa acicularis, contained the largest amount of DNA, about three times that of the diploid, R. woodsii. Another diploid species, R. blanda, contained less DNA than R. woodsii. One specimen, identified as R. blanda with some introgression from R. woodsii, had the same amount of DNA as the latter species. R. × dulcissima, a hybrid between R. blanda and R. woodsii, had DNA contents similar to R. woodsii. The origin of a tetraploid, with DNA contents intermediate between diploid and hexaploid species, and 14 bivalents in diakinesis, was suggested to be hybridization between R. acicularis and a diploid rose. Chromosome behaviour in meiosis and DNA content were used in a discussion of interspecific relationships.

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Variation in Ploidy Levels and Reproductive Pathways Among Flowering Crabapples

HortScience ◽

10.21273/hortsci.39.4.773b ◽

2004 ◽

Vol 39 (4) ◽

pp. 773B-773

Author(s):

Thomas Ranney* ◽

Thomas Eaker

Keyword(s):

Ploidy Level ◽

Dna Content ◽

Nuclear Dna ◽

Nuclear Dna Content ◽

Unreduced Gametes ◽

Breeding Programs ◽

Ploidy Levels ◽

Level Measurement ◽

Dna Contents

Information on ploidy levels is extremely valuable for use in plant breeding programs. Fertility, crossability, and heritability of traits are all influenced by ploidy levels. Knowledge of reproductive pathways, including occurrence of apomixes, pseudogamy, and formation of unreduced gametes can also be important information for developing breeding strategies. Although ploidy level can be determined by counting chromosomes, flow cytometry provides a reliable and much faster means for determination of nuclear DNA content and associated ploidy level. Measurement of ploidy levels of seeds (embryo and endosperm) can also provide useful insights into reproductive pathways. The objective of this study was to determine the approximate genome size, estimated ploidy level, and range of reproductive pathways of a diverse collection of flowering crapbapples (Malus spp.). Genome sizes were calculated as nuclear DNA content for unreduced tissue (2C). Results from the taxa included in our survey showed DNA contents ranging from 1.52 to 1.82 for diploids, 2.40 to 2.62 for triploids, and 3.36 to 3.74 pg/2C for tetraploids. Based on these ranges, we identified 43 diploid, 10 triploid, and 4 tetraploid crabapple taxa in this collection. Results from open pollinated seeds and seedlings demonstrated a variety of reproductive pathways including apomixes and unreduced gametes. This research provides information on ploidy levels and reproductive pathways of flowering crabapples and will allow for more systematic and efficient progress in the development of improved cultivars.

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Compatibility Studies in Hydrangea

Journal of Environmental Horticulture ◽

10.24266/0738-2898-18.1.29 ◽

2000 ◽

Vol 18 (1) ◽

pp. 29-33 ◽

Cited By ~ 1

Author(s):

S. M. Reed

Keyword(s):

Cold Hardiness ◽

The Self ◽

Interspecific Crosses ◽

Putative Hybrid ◽

Compatibility Studies ◽

Maternal Parent ◽

Hydrangea Macrophylla ◽

Self Compatibility ◽

Viable Seeds ◽

Cotyledonary Stage

Abstract Improvement in cold-hardiness is needed in bigleaf hydrangea (Hydrangea macrophylla). Potential sources of cold-hardiness for enhancing the usefulness of this popular shrub include panicle hydrangea (H. paniculata), smooth hydrangea (H. arborescens), and oakleaf hydrangea (H. quercifolia). The objective of this study was to investigate the possibility of creating hybrids between these three species and H. macrophylla. In addition, self-compatibility of each of the species was evaluated to determine the need for emasculation when making controlled pollinations. Numerous cultivars of the species were utilized in both the self-pollination and interspecific hybridization studies. Number of flowers self-pollinated ranged from 1000 in H. arborescens to 3000 in H. quercifolia. Viable seeds were obtained from all species except H. arborescens. All five of H. quercifolia, 9 of the 18 H. paniculata, and 1 of the 8 H. macrophylla self progeny obtained survived. Emasculation of Hydrangea flowers to be used in controlled pollinations is therefore recommended. Seedlings were obtained from all interspecific crosses in which H. macrophylla was used as the maternal parent. All putative hybrid seedlings died either at the cotyledonary stage or while the first set of true leaves was expanding.

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Cytogenetic and Pollination Studies in the Genus Verticordia DC

Australian Journal of Botany ◽

10.1071/bt9910261 ◽

1991 ◽

Vol 39 (3) ◽

pp. 261 ◽

Cited By ~ 2

Author(s):

AP Tyagi ◽

J Mccomb ◽

J Considine

Keyword(s):

Chromosome Number ◽

Chromosome Numbers ◽

Seed Set ◽

Interspecific Crosses ◽

Root Tips ◽

Chromosome Counts ◽

Flower Buds ◽

Taxonomic Distance ◽

Self Compatibility ◽

High Level

Aspects of the genetic and physiological barriers to hybridisation have been assessed for the genus Verticordia which contains many species with significant potential for ornamental horticulture. The chromosome numbers of 52 species were analysed using flower buds and root tips. Previously published reports on chromosome numbers were confirmed for 21 species and new numbers reported in a further 31. Self compatibility was present in 20 species and only three species were shown to possess barriers to self pollination. Seed set occurred in two of six interspecific crosses carried out within sections. In 21 wider crosses the degree of pollen tube development was increasingly repressed with taxonomic distance. The chromosome counts also support the reclassification of the genus Verticordia into three subgenera: Chrysoma, Verticordia and Eperephes. Species within each section of a subgenus generally had the same chromosome number. Exceptions occurred in the subgenus Verticordia, sections Verticordia, Intricata and Micrantha. In species with one or two ovules, the chromosome number was also low (6, 7, 8 or 9) while species with six or more ovules had a higher chromosome number (11 or 22). There was, however, no relationship between chromosome number and chromosome size, nor between chromosome number and any observed feature which might be attributable to polyploidy or allopolyploidy. With the possible exception of V. grandis, which displayed loss of seasonality in flowering, all putative polyploids behaved developmentally as diploids and displayed a high level of male fertility.

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Ploidy Level, Karyotype, and DNA Content in the Genus Lonicera

HortScience ◽

10.21273/hortsci12489-17 ◽

2017 ◽

Vol 52 (12) ◽

pp. 1680-1686 ◽

Cited By ~ 3

Author(s):

Juan Chen ◽

Nianhe Xia ◽

Xiaoming Wang ◽

Richard C. Beeson ◽

Jianjun Chen

Keyword(s):

Dna Content ◽

Chromosome Numbers ◽

Crop Improvement ◽

Basic Chromosome Number ◽

Asymmetry Index ◽

Plant Evolution ◽

Ploidy Levels ◽

Basic Chromosome ◽

Dna Contents ◽

Breeding Efficiency

Ploidy levels and genome sizes have significant implications in plant evolution and crop improvement. Species of Lonicera L. have long been cultivated as medicinal, ornamental crops, or both. However, chromosome numbers, karyotypes, and DNA contents have only been documented in a few species, of which some controversies regarding basic chromosome numbers and karyotypes remain. This study analyzed the chromosome numbers and karyomorphology of 11 cultivars across four species and also the DNA content of 10 cultivars representing six species of Lonicera. Among them, the chromosome numbers of nine cultivars are reported for the first time. Results showed that the basic chromosome number of x = 9 was constant, and chromosome numbers of 2n = 18, 27, 36, or 54 were observed, suggesting that polyploidy exists in the genus. Five cultivars are diploid with 2n = 18; one cultivar is triploid, four are tetraploid, and one is hexaploid. The karyotypes of all studied cultivars are 3B or 3A, except Lonicera sempervirens ‘Crimson Cascade’ that is 2B based on the Stebbins’ asymmetry classification of karyotypes. The asymmetry index (A1) values vary from 0.47 to 0.60. The chromosome lengths range from 0.77 to 4.09 μm. Total karyotype lengths differ from 33.55 to 78.71 μm. The 1C-value of 10 cultivars varies 3-fold, ranging from 1.158 to 3.664 pg. Information gathered from this study could be valuable for improving breeding efficiency in the development of new cultivars of Lonicera with enhanced medicinal, ornamental value, or both.

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