The structure of the stomatal complex (the shape and arrangement of the subsidiary cells) was different in each Pinus species

Figure 2. Stomatal variables: Aa, stomatal width; La, stomatal length; Ab, upper woody lamellar width; Lb, upper woodylamella length; lc, distance between the external limits of the medial lamellae borders measured at the centre; ld, distancebetween the external limits of the medial lamellae borders measured at the point at which both meet to form the stem;e, medial lamellae border width; Lt, stem length; At, stem width; a, angle of attachment of the upper woody lamella; b,angle between the stem and medial lamellae border; coef_a = Aa/La, stomatal width ratio. Terminology based on that ofFlorin (1931), Trautmann (1953) and Hansen (1995) (Appendix).

The value of leaf cuticle characteristics in the identification and classification of Iberian Mediterranean members of the genus Pinus

Garcia Alvarez S., Garcia-Amorena I., Rubiales J. M., Morla C. (2009)

SALVIA GARCÍA ÁLVAREZ, IGNACIO GARCÍA-AMORENA, JUAN M. RUBIALES, CARLOS MORLA

Unidad Docente de Botánica, Escuela Técnica Superior de Ingenieros de Montes, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain

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Botanical Journal of the Linnean Society 161: 436–448 –

https://oa.upm.es/5073/2/INVE_MEM_2009_64103.pdf

https://www.researchgate.net/publication/227644426_The_value_of_leaf_cuticle_characteristics_in_the_identification_and_classification_of_Iberian_Mediterranean_members_of_the_genus_Pinus

Figure 3. Stomatal rows of Pinus nigra subsp. salzmannii.

This study reports the value of leaf cuticle characteristics in the identification and classification of Iberian Mediterranean species of the genus Pinus (P. nigra subsp. salzmannii, P. pinaster, P. pinea and P. halepensis), with the aim of using these characters to identify isolated cuticles and stomata in palynology slides.

Preparations were made of the cuticles of pine needles belonging to one natural Iberian population of each of the above species. A number of epidermal morphological characteristics were then recorded with the aim of distinguishing these species from one another.

The structure of the stomatal complex (the shape and arrangement of the subsidiary cells) was different in each species. The aperture of the epistomatal chamber was significantly smaller in P. pinea than in the other species examined, and the variables recorded for the thickening of the guard cells provided relationships that clearly distinguished all four taxa.

The width and length of the stomata and the upper woody lamellae, the central distance between the external limits of the medial lamellae borders and the length of the stem were the most useful variables in this respect.

The present results contribute to the ongoing discussion regarding the taxonomic classification of the members of Pinus, and provide valuable clues for the identification of Iberian Mediterranean pine species from small pine needle fragments or isolated stomata.

After validation of the present results for multiple populations, these results could also be used to help identify fossil leaf macroremains and the scattered/isolated stomata commonly observed in palaeopalynological samples.

Stomata in Abies and Picea

Figure 1   SEM micrograph of abaxial faces from Abies species. A, B A. firma. A Stomatal band. B Stomata magnified. C, D A. holophylla. C Stomatal band. D Stomata magnified. E, F A. koreana. E Stomatal band. F Stomata magnified. G, H A. nephrolepis. G Stomatal band. H Stomata magnified. Abbreviations: gc, guard cell; mv, mid vein; sb, stomatal band; sc subsidiary cells; st, stomata. Scale bars: A, C, E, G = 1 mm; B, D, F, H = 50 µm.

Comparative leaf anatomy of some species of Abies and Picea (Pinaceae)

Ghimire B., Lee C., Yang J., Heo K. (2015)

Balkrishna Ghimire
Department of Applied Plant Science, Kangwon National University, Chuncheon 200-701, KoreaDivision of Plant Conservation, Korea National Arboretum, Pocheon 487-829, Korea

Chunghee Lee
Korea National Arboretum, Pocheon 487-829, Korea

Jongcheol Yang
Korea National Arboretum, Pocheon 487-829, Korea

Kweon Heo 
Department of Applied Plant Science, Kangwon National University, Chuncheon 200-701, Korea

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Acta Bot. Bras. 29(3):  – https://doi.org/10.1590/0102-33062014abb0009 –

https://www.scielo.br/j/abb/a/MjNwf9Bw3VW3jbzJxKVFgJt/?lang=en

Figure 2   SEM micrograph of abaxial faces from Picea species. A, B P. abies. A Stomatal band. B Stomata magnified. C, D P. jezoensis. C Stomatal band. D Stomata magnified. E, F P. koraiensis. E Stomatal band. F Stomata magnified. Abbreviations: gc, guard cell; mv, mid vein; sb, stomatal band; sc subsidiary cells; st, stomata. Scale bars: A = 500 µm; B, D, F = 50 µm; C, E = 1 mm.

ABSTRACT

A number of conifer species are still lacking anatomical data, which is significant because morphological and anatomical data are essential for systematic study.

Leaf anatomy was studied in selected species of Abies and Picea using light and scanning electron microscopy. Both genera were found to have typical coniferous and highly xerophytic leaves with sunken stomata and an epidermis covered by a thick cuticle.

In the genus Abies, species can be differentiated by the nature of the lignified hypodermis and the number and position of resin ducts. Abies firma and A. holophylla have a continuous hypodermis whereas in A. koreana and A. nephrolepis the hypodermis is discontinuous and represented by isolated cells or groups of four or five cells.

On the other hand, in Picea leaf shape, stomata arrangement, and number, position, and nature of resin ducts are the key features for species differentiation. Picea jezoensis has a flattened leaf with stomata distributed on the adaxial surface whereas P. abies and P. koraiensis have a rectangular leaf with stomata found on surfaces.

New insights on stomata analysis of European conifers 65 years after the pioneering study of Werner Trautmann (1953)

Finsinger W., Tinner W. (2020)

Walter Finsinger1, Willy Tinner2,

1 ISEM, Univ Montpellier, CNRS, EPHE, IRD, 34095 Montpellier, France
2 Oeschger Centre for Climate Change Research and Institute of Plant Sciences, University of Bern, Bern, Switzerland

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Vegetation History and Archaeobotany, Springer Verlag 29: 393-406 – 10.1007/s00334-019-00754-1

hal-02319673

https://hal.archives-ouvertes.fr/hal-02319673/document

Discrimination of populations considering number of rows of stomata and total number of stomata

Genetic variation in morphological and anatomical needle characteristics in Pinus brutia Ten.

Calamassi R. 1, Puglisi S. R. 2, Vendramin G. G. 2, (1988) – – Silvae Genetica 37: 5-6 –

https://www.thuenen.de/media/institute/fg/PDF/Silvae_Genetica/1988/Vol._37_Heft_5-6/37_5-6_199.pdf

Stomatal distribution on leaves of Chamaecyparis

Stomatal distribution on leaves of three species of Chamaecyparis

Zobel D. B., Lin T.-P., Liu V. T. (1978)

Donald B. Zobel, Tsan-Piao Lin, Valiant T. Liu,

Taiwania 23: 1-6 – DOI: 10.6165/tai.1978.23.1

https://taiwania.ntu.edu.tw/pdf/tai.1978.23.1.pdf

https://taiwania.ntu.edu.tw/abstract.php?type=abstract&id=594

Stomatal development in Zamiaceae

Stomatal development in the cycad family Zamiaceae

Coiro M., Lumaga B., Rosaria M., Rudall P. J. (2021 )

Coiro Mario, Barone Lumaga, Maria Rosaria, Rudall Paula J.,

Annals of Botany XX: 1–12 – https://doi.org/10.1093/aob/mcab095 –

https://www.zora.uzh.ch/id/eprint/205151/13/mcab095%281%29.pdf

Fig. 4. Bowenia spectabilis. (A, B). Transverse section of stomatal complex of an adult leaflet stained with pseudo-Schiff-propidium iodide observed using confocal laser scanning microscopy and imaged using (A) UV excitation, (B) propidium iodide excitation. (C) Fluorescence micrograph of isolated cuticle from
adult leaflet stained with Auramine O, showing mature stomata in axial cell files. (D) Fluorescence micrograph of isodiametric protodermal cells in developing leaflet. (E–G) Development of stomatal complexes at different stages. Scale bars = 50 µm. Abbreviations: GMC, guard mother cell; GC, guard cell; LSC, lateral subsidiary cell.

Abstract: (Sent by Submission form by Mario COIRO)

Background and Aims
The gymnosperm order Cycadales is pivotal to our understanding of seed-plant phylogeny because of its phylogenetic placement close to the root node of extant spermatophytes and its combination of both derived and plesiomorphic character states. Although widely considered a ‘living fossil’ group, extant cycads display a high degree of morphological and anatomical variation. We investigate stomatal development in Zamiaceae to evaluate variation within the order and homologies between cycads and other seed plants.

Methods
Leaflets of seven species across five genera representing all major clades of Zamiaceae were examined at various stages of development using light microscopy and confocal microscopy.

Fig. 8. Zamia. (A, B) Zamia integrifolia, early developmental stages; (C–G) Zamia roezlii, differentiated stomata. (A) Protodermal cells. (B) Early stage with GMCs undergoing division, arranged in axially orientated cell files. (C) Surface view showing stomatal openings surrounded by encircling cells. (D) Young stoma with dividing lateral subsidiary cells. (E) Mature stoma with encircling cells and wall thickenings on guard cells. (F, G) Transverse sections showing successive stages of maturing stomata with guard cells already differentiated; in G the guard cells are sunken due to enlargement of the encircling subsidiary cells. Scale bars = 50 µm. Abbreviations: GMC, guard-cell mother cell; GC, guard cell.



Key Results
All genera examined have lateral subsidiary cells of perigenous origin that differ from other pavement cells in mature leaflets and could have a role in stomatal physiology. Early epidermal patterning in a ‘quartet’ arrangement occurs in Ceratozamia, Zamia and Stangeria. Distal encircling cells, which are sclerified at maturity, are present in all genera except Bowenia, which shows relatively rapid elongation and differentiation of the pavement cells during leaflet development.

Conclusions
Stomatal structure and development in Zamiaceae highlights some traits that are plesiomorphic in seed plants, including the presence of perigenous encircling subsidiary cells, and reveals a clear difference between the developmental trajectories of cycads and Bennettitales. Our study also shows an unexpected degree of variation among subclades in the family, potentially linked to differences in leaflet development and suggesting convergent evolution in cycads.