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Abstract

This study is the first comparison of the morphology of pollen grains in ten cultivars of three species of the Taxus,

Torreya nucifera and Cephalotaxus harringtonia var. drupacea genera. The material came from the Botanical

Garden of Adam Mickiewicz University in Poznań, Poland. Each measurement sample consisted of 50 pollen

grains. In total, 750 pollen grains were analyzed. Light and electron scanning microscopy was used for the morphometric

observation and analysis of pollen grains. The pollen grains were inaperturate and classified as small

and medium-sized. They were prolate-spheroidal, subprolate to prolate in shape. The surface of the exine was

microverrucate-orbiculate, perforate in Cephalotaxus harringtonia var. drupacea, granulate-orbiculate, perforate

in all Taxus taxa and granulate-microverrucate-orbiculate, perforate in Torreya. The orbicules were rounded to

oval in surface view, and the size was considerably diversified. The pollen features were insufficient to distinguish

between individual Taxus members – only groups were identified. The values of the coefficient of variability of

three features (LA, SA and LA/SA) were significantly lower than the orbicule diameter. The pollen surface of all

Taxus specimens was similar, so it was not a good identification criterion. The pollen grains of the Taxus taxa

were smaller and had more orbicules than Cephalotaxus and Torreya. Palynological studies provided taxonomic

support for recognition of two different genera of the Cephalotaxaceae and Taxaceae families, which are closely

related.

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Authors and Affiliations

Joanna Bykowska
Małgorzata Klimko
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Abstract

Chromosome numbers for 15 taxa of Hieracium L. s.str. from Bulgaria, Greece, Macedonia, Poland, Romania

and Slovakia are given and their metaphase plates are illustrated. Chromosome numbers are published for the

first time for H. vagneri Pax s.str. (2n = 4x = 36), H. wiesbaurianum subsp. herculanum Zahn (2n = 4x = 36),

H. wiesbaurianum subsp. kelainephes Nyár. & Zahn (2n = 3x = 27), as well as for two undescribed species

of hybrid origin between H. umbellatum L. and H. wiesbaurianum s.lat. (2n = 3x = 27), and between H. sparsum

Friv. and H. schmidtii s.lat. (2n = 3x = 27), and for three undescribed species of the H. djimilense agg.

(2n = 3x = 27), H. heldreichii agg. (2n = 3x = 27), and H. sparsum agg. (2n = 3x = 27). Furthermore, the chromosome

numbers of two undescribed species of hybrid origin between H. umbellatum L. and H. wiesbaurianum

s.lat. (2n = 3x = 27), and between H. sparsum Friv. and H. schmidtii s.lat. (2n = 3x = 27) are given. A new,

tetraploid chromosome number is given for H. barbatum Tausch from the northernmost locality of the species

in Europe.

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Authors and Affiliations

Krystyna Musiał
Agnieszka Janas
Zbigniew Szeląg
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Abstract

An efficient system of micropropagation via somatic embryogenesis from root-derived callus was established in

Arabica coffee (Coffea arabica L.). Twenty-six callus lines were induced on MS (Murashige and Skoog, 1962)

medium supplemented with combinations of NAA (0, 0.1, 0.5, 1 and 2 mg/L) plus BA (0, 1 and 2 mg/L), or 2,4-D

(0, 0.1, 0.5, 1 and 2 mg/L) plus TDZ (0, 1 and 2 mg/L). Subsequently, two types of somatic embryos were obtained

from callus cultures and named S-type and I-type embryos. The S-type embryos were obtained from an 18-monthold

callus line which was induced and maintained at 2 mg/L TDZ and 0.1 mg/L 2,4-D near the end of each period

of the subculture. These embryos have a developmental barrier, which did not pass through the torpedo stage

and could be overcome by a supplement of 2 or 5 mg/L BA. The I-type embryos were induced from 3-month-old

callus when transferred onto induction media, i.e., MS supplemented with TDZ (2 and 5 mg/L) plus 2,4-D (0 and

0.1 mg/L). The significantly highest response, i.e., 13.3 embryos per callus clump was obtained at 2 mg/L TDZ.

In this study, the results reveal that TDZ has a crucial effect on embryogenic callus induction, proliferation and

subsequent somatic embryogenesis.

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Authors and Affiliations

Yi-Chieh Wang
Meng-Ze Lin
Bin Huang
Hsiao-Hang Chung
Jen-Tsung Chen
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Abstract

Plant tissue culture techniques have become an integral part of progress in plant science research due to the opportunity offered for close study of detailed plant development with applications in food production through crop improvement, secondary metabolites production and conservation of species. Because the techniques involve growing plants under controlled conditions different from their natural outdoor environment, the plants need adjustments in physiology, anatomy and metabolism for successful in vitro propagation. Therefore, the protocol has to be optimized for a given species or genotype due to the variability in physiological and growth requirement. Developing the protocol is hampered by several physiological and developmental aberrations in the anatomy and physiology of the plantlets, attributed to in vitro culture conditions of high humidity, low light levels and hetero- or mixotrophic conditions. Some of the culture-induced anomalies become genetic, and the phenotype is inherited by clonal progenies while others are temporary and can be corrected at a later stage of protocol development through changes in anatomy, physiology and metabolism. The success of protocols relies on the transfer of plantlets to field conditions which has been achieved with many species through stages of acclimatization, while with others it remains a challenging task. This review discusses various adjustments in nutrition, physiology and anatomy of micro-propagated plants and field grown ones, as well as anomalies induced by the in vitro culture conditions.

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Authors and Affiliations

Beata Myśków
Ilona Czyczyło-Mysza
Sandra Sokołowska
Stefan Stojałowski

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