scholarly journals CHROMOSOME NUMBER, NUCLEAR VOLUME AND POLLEN GRAIN SIZE IN GALEOPSIS

Hereditas ◽  
2010 ◽  
Vol 10 (3) ◽  
pp. 241-260 ◽  
Author(s):  
ARNE MÜNTZING
Keyword(s):  
Grain Size ◽  
Chromosome Number ◽  
Pollen Grain ◽  
Nuclear Volume ◽  
Pollen Grain Size

scholarly journals A Cytotaxonomic study on Minuartia L. (Caryophyllaceae) in Iraq

2019 ◽  
Vol 32 ◽  
pp. 207-216
Author(s):  
Sadeq S. Kareem Al-Tai ◽  
Sahar A.A. Malik Al-Saadi
Keyword(s):  
Grain Size ◽  
Chromosome Number ◽  
Karyotype Analysis ◽  
Ring Chromosome ◽  
Chromosome Count ◽  
Pollen Grain ◽  
Study Analysis ◽  
Metaphase Stage ◽  
Karyotype Formula ◽  
Pollen Grain Size

Chromosome count, karyotypic character analysis, meiotic studies, monoploid karyograms and ideograms were performed in six taxa of Minuartia growing in Iraq (M. hamata, M. hybrida subsp. hybrida, M. intermedia, M. meyeri, M. picta and  M. hybrida subsp. turcica). Species of M. hamata and M. meyeri showed 2n=2x=30 chromosome number, while M. hybrida subsp. hybrida and M. intermedia  were diploid (26). The chromosome number (n=x) of six species was studied, and was found to be n=15 in M. hamata and M. meyeri, 13 in M. hybrida and M. intermedia, while in M. picta we recorded values of n= 11 and 14. Karyotype analysis of this species was first carried out in our study. Analysis of metaphases showed that the karyotype formula was mainly metacentric, submetacentric, and sub acrocentric. The sizes of the chromosomes were mainly small and very small. The course of meiosis varied from normal to abnormal. Abnormal microsporogenesis formation of two bridge chromosomes was detected in M. hamata and one bridge chromosome in M. intermedia and M. meyeri. Formation of laggard’s chromosomes was detected in M. hamata, M. meyeri   and M. intermedia. As well as ring chromosome was showed in M. hybrida subsp. hybrida, also, some cells contain triad cell in metaphase stage instead four cells, as well as founded cell, contains two nuclei in same species which led to reduced pollen fertility and differences in pollen grain size.

scholarly journals Palynology of the Genus Stachytarpheta Vahl. (Verbenaceae)

2010 ◽  
Vol 2 (4) ◽  
pp. 27-33
Author(s):  
Olubukola ADEDEJI
Keyword(s):  
Cluster Analysis ◽  
Grain Size ◽  
Evolutionary History ◽  
Pollen Grains ◽  
Pollen Grain ◽  
The Other ◽  
Pollen Grain Size ◽  
Pollen Diameter ◽  
Stachytarpheta Cayennensis ◽  
Exine Morphology

The exine morphology of pollen grains of Stachytarpheta indica (Linn.) Vahl, Stachytarpheta cayennensis (Rich.) Vahl and Stachytarpheta angustifolia (Mill.) Vahl is reported. This study was carried out with a light microscope. Pollen grains from fresh anthers were collected and aceolysed. Statistical analysis used to analyse the data collected include cluster analysis, correlation analysis, similarity and distance indices. The pollen grains are spheroidal to oblate to sub-oblate in shape. They are aperturate, both colpate and porate. Tricolpate types occur most frequently, acolpate, monocolpate, bicolpate and tetracolpate types less frequently. The multicolpate and multiporate attributes in all the species indicate that the genus is not primitive in evolutionary history and this species probably, evolved around in the same time. According to the size, the pollen grains of the genus falls into groups permagna (pollen diameter 100-200 μm) and giganta (pollen diameter greater than 200 μm). S. cayennensis and S. anguistifolia belong to group permagna and S. indica only in the group giganta. This separates S. indica from the other two species. The large pollen grain size in the genus clearly supports the fact that the flowers in the genus are more insect-and-bird pollinated than wind pollinated. The similarity and distance indices of the species showed that S. cayennensis and S. angustifolia are the closest. S. indica is closer to S. angustifolia but farther from S. cayennensis.

scholarly journals Differences in stomatal and pollen grain dimensions and pollen viability between Paspalum rawitscheri populations

2020 ◽  
Vol 42 ◽  
pp. e46
Author(s):  
Jéssica Mena Barreto De Freitas ◽  
Andrielle Wouters Kuhn ◽  
Viviane Dal-Souto Frescura ◽  
Liliana Essi ◽  
Solange Bosio Tedesco
Keyword(s):  
Grain Size ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Low Fertility ◽  
Leaf Epidermis ◽  
Stomatal Size ◽  
Pollen Grain Size ◽  
Different Populations ◽  
Santa Maria

The objective of this study was to evaluate stomatal and pollen grain size and to estimate pollen viability of individuals from different populations of Paspalum rawitscheri (Parodi) Chase ex G.H. Rua Valls. To analyze stomatal size, slides were made of the adaxial leaf epidermis using the epidermal impression method. The height and width of 100 stomata per population were analyzed. Pollen was obtained from inflorescences to evaluate pollen grain size and pollen viability. Pollen grains were stained with 2% acetic orcein, 2% acetic carmine, or Alexander’s reactive stain. Per population, 1600 grains of pollen were observed for viability, and 50 grains of pollen were measured. There were significant differences between populations in stomatal height and pollen grain height and width. The populations also differed in pollen viability, with the Santa Maria population showing the lowest viability. The differences in stomatal and pollen grain size suggest genetic variability in the evaluated populations. Moreover, low pollen viability in one population indicates that its decline may be related to low fertility. Keywords: Grass. Ploidy. Fertility. Threatened species.

scholarly journals Male gametophytic generation and a possible approach for selective pollination in carnation (Dianthus) breeding program

2011 ◽  
Vol 48 (No. 8) ◽  
pp. 368-375
Author(s):  
Tejaswini
Keyword(s):  
Grain Size ◽  
Pollen Tube ◽  
Dianthus Caryophyllus ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Breeding Program ◽  
Germination Capacity ◽  
Causal Organism ◽  
Pollen Tube Growth Rate ◽  
Pollen Grain Size

Present study focuses on making best possible use of male gametophytic generation in carnation breeding program. Exploration of pollen population revealed the existence of variability in terms of pollen morphology and histochemical content among as well as within varieties and species of Dianthus caryophyllus and D. chinensis sufficient to make selection. Pollen grain size and histochemical content were found to be associated with germination capacity and pollen tube growth rate. In addition, pollen germination capacity and elongation of pollen tube in response to presence of culture filtrate from F. oxysporum. f.sp. dianthi causal organism of fusarium wilt in carnation was found to be governed by pollen grain size and histochemical content of pollen grains. Entire result suggests the possibility of selecting the desired pollen grains from a pollen population and possibility of attempting selective pollination in carnation breeding program.

scholarly journals Laboratory Techniques for Determining Ploidy in Plants

1999 ◽  
Vol 9 (4) ◽  
pp. 594-596 ◽  
Author(s):  
Christopher S. Cramer
Keyword(s):  
Grain Size ◽  
Mother Cell ◽  
Pollen Grain ◽  
Root Tip ◽  
Plant Tissues ◽  
Breeding Technique ◽  
Laboratory Techniques ◽  
Stomata Size ◽  
Pollen Grain Size

Determination of ploidy is an essential plant breeding technique. Laboratory exercises for teaching students how to determine ploidy in plant tissues using various techniques are described for geranium and onion. The different methods include root tip squashes, pollen mother cell squashes, pollen grain size and germinal pore counts, stomata size and density determination, and gross morphology.

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