Variation in Pollen Size, Fertilization Ability, and Postfertilization Siring Ability in Erythronium grandiflorum

Evolution ◽  
1990 ◽  
Vol 44 (4) ◽  
pp. 843 ◽  
Author(s):  
Mitchell B. Cruzan
Keyword(s):  
Pollen Size ◽  
Erythronium Grandiflorum ◽  
Siring Ability

Evolution of Angiosperm Pollen: 8. Lamiids

2020 ◽  
Vol 105 (3) ◽  
pp. 323-376
Author(s):  
Li-E Yang ◽  
Lu Lu ◽  
Kevin S. Burgess ◽  
Hong Wang ◽  
De-Zhu Li
Keyword(s):  
Maximum Likelihood ◽  
Pollen Morphology ◽  
Pollen Size ◽  
State Transitions ◽  
Character State ◽  
Evolutionary Mechanisms ◽  
Pollen Characters ◽  
Exine Ornamentation ◽  
Shape Class ◽  
Pollen Character

Lamiids, a clade composed of approximately 15% of all flowering plants, contains more than 50,000 species dispersed across 49 families and eight orders (APG IV, 2016). This paper is the eighth in a series that analyzes pollen characters across angiosperms. We reconstructed a maximum likelihood tree based on the most recent phylogenetic studies for the Lamiids, comprising 150 terminal genera (including six outgroups) and covering all eight orders and 49 families within the clade. To illustrate pollen diversity across the Lamiids, pollen grains from 22 species (22 genera in 14 families) were imaged under light, scanning, and transmission electron microscopy. Eighteen pollen characters that were documented from previous publications, websites, and our new observations were coded and optimized onto the reconstructed phylogenetic tree using Fitch parsimony, maximum likelihood, and hierarchical Bayesian analysis. Pollen morphology of the Lamiids is highly diverse, particularly in shape class, pollen size, aperture number, endoaperture shape, supratectal element shape, and tectum sculpture. In addition, some genera show relatively high infrageneric pollen variation within the Lamiids: i.e., Coffea L., Jacquemontia Choisy, Justicia L., Pedicularis L., Psychotria L. nom. cons., Sesamum L., Stachytarpheta Vahl, and Veronica L. The plesiomorphic states for 16 pollen characters were inferred unambiguously, and 10 of them displayed consistent plesiomorphic states under all optimization methods. Seventy-one lineages at or above the family level are characterized by pollen character state transitions. We identified diagnostic character states for monophyletic clades and explored palynological evidence to shed light on unresolved relationships. For example, palynological evidence supports the monophyly of Garryales and Metteniusaceae, and sister relationships between Icacinaceae and Oncothecaceae, as well as between Vahliales and Solanales. The evolutionary patterns of pollen morphology found in this study reconfirm several previously postulated evolutionary trends, which include an increase in aperture number, a transition from equatorially arranged apertures to globally distributed ones, and an increase in exine ornamentation complexity. Furthermore, there is a significant correlation between pollen characters and a number of ecological factors, e.g., pollen size and pollination type, pollen ornamentation and pollination type, and shape class and plant growth form. Our results provide insight into the ecological, environmental, and evolutionary mechanisms driving pollen character state changes in the Lamiids.

CYTOLOGY OF POPLAR SPECIES AND NATURAL HYBRIDS

1938 ◽  
Vol 16c (11) ◽  
pp. 445-455 ◽  
Author(s):  
F. H. Peto
Keyword(s):  
Size Distribution ◽  
Genetic Factors ◽  
Chromosome Complement ◽  
Pollen Grains ◽  
Pollen Size ◽  
Cell Nuclei ◽  
Good Pollen ◽  
Natural Hybrids ◽  
Pollen Diameter ◽  
High Degree

Complete analyses of pollen-mother-cell nuclei at first metaphase, percentage good pollen, pollen diameter and pollen-size distribution were determired for the following poplar species and natural hybrids: Populus grandidentata Michx., P. tremuloides Michx., P. eugenei Simon Louis, P. alba L., P. canescens Sm., natural hybrids of P. alba × P. grandidentata and of P. alba × P. tremuloides.Both of the P. alba and two of the four P. canescens trees examined were triploids (2n = 57) while all other trees examined were diploids (2n = 38). Meiotic observations on the natural hybrids indicated a high degree of homology between the chromosomes of P. alba and the native aspens (P. grandidentata and P. tremuloides), since 17 to 19 bivalents were usually found at first metaphase. In collections from one triploid P. canescens and two diploid alba-grandidentata hybrid trees, failure of a high proportion of the chromosomes to pair was attributed to genetic factors limiting pairing, rather than to non-homology.Pollen characters such as percentage good pollen, pollen diameter, and pollen size distribution were, in most cases, not indicative of the chromosome number or pairing relations at first metaphase. Consequently, triploids could not be detected by pollen observations under the conditions of this experiment. In spite of the lack of correlation between first metaphase and pollen observations, abnormally large pollen grains were observed in collections from several of the trees, and these were considered to contain the diploid or unreduced chromosome complement. The tendency for the poplars to produce unreduced pollen grains probably accounts for the number of triploid trees discovered in Canada and Sweden.

Parsing a plethora of pollen: the role of pollen size and shape in the evolution of Boraginaceae

Cladistics ◽  
2021 ◽  
Author(s):  
Maryam Noroozi ◽  
Farrokh Ghahremaninejad ◽  
David Bogler ◽  
Jocelyn M. Witherspoon ◽  
Gillian L. Ryan ◽  
...  
Keyword(s):  
Pollen Size ◽  
Size And Shape

Effect of growth substances on the expression of flowering and study on pollen viability of hermaphrodite & male ower in the female clone “Mondouri local” of Teasle gourd (Momordica subangulata Blume. subsp. renigera)

2019 ◽  
Vol 8 (2) ◽  
pp. 63-66
Author(s):  
Abhishek Naik ◽  
Shirin Akhtar ◽  
Arup Chattopadhyay ◽  
Umesh Thapa ◽  
Pranab Hazra
Keyword(s):  
Gibberellic Acid ◽  
Pollen Tube ◽  
Silver Nitrate ◽  
Pollen Viability ◽  
Pollen Size ◽  
Normal Male ◽  
Growth Substances ◽  
Flowering Stage ◽  
Foliar Sprays ◽  
Small Pollen

Foliar sprays with gibberellic acid (GA) and silver nitrate (AgNO3) of di erent concentra ons at pre-flowering stage induced hermaphrodite and male owers on strictly gynoecious vines of teasle gourd (Momordica subangulata Blume. subsp. renigera). GA at 1500 ppm and AgNO3at 500 ppm were effective inducing more than 50% male owers in the female clone “Mondouri local”. AgNO3 at 750 ppm was effective in inducing 36.6% male and 33.9% hermaphrodite owers on same plant. The hermaphrodite ower had higher pollen size (103.57 μm) compared to that of natural male ower (94.94 μm). However, there existed no variation between pollen viability of bisexual ower (81.6%) and normal male ower (89.1%). However, germinability of the pollen of hermaphrodite ower was very low (14.16%) producing very small pollen tube (9 μm), though the bisexual ower did not produce any fruit on self-pollination.

scholarly journals Microsporogenesis and pollen formation in Larch Sukachev (Larix Sukaczewii Djil.) on permanent forest seed plot in Semiluksky forestry

2021 ◽  
Vol 25 (3) ◽  
pp. 42-48
Author(s):  
E.E. Kulakov ◽  
◽  
A.I. Sivolapov ◽  
Keyword(s):  
Significant Proportion ◽  
Spherical Shape ◽  
Pollen Size ◽  
Seed Plot ◽  
Male And Female ◽  
Division Spindle ◽  
Sterile Pollen ◽  
Pollen Formation ◽  
Sukachev Larch

The formation of male and female generative buds in the Sukachev larch in the conditions of Voronezh in the second decade of August is considered. The behavior of chromosomes in the meta-, ana -, and telophase of the first and second divisions of meiosis is analyzed. In each phase, 150–200 microsporocytes were taken into account. According to the results of the conducted studies, it was revealed that the microsporogenesis of larch proceeded asynchronously. A significant proportion of the disorders are caused by chromosome lag and the formation of bridges, the formation of a hexad, and the release of chromosomes outside the division spindle. The viability of Sukachev larch pollen is estimated to be high. A small number of disturbances in the process of meiotic divisions and the formation of gametophytes did not lead to the formation of a significant amount of sterile pollen. The average pollen size varies between 82.18–86.4 microns. Pollen has a spherical shape

Palynological analysis of five selected Onosma taxa

Biologia ◽  
2008 ◽  
Vol 63 (2) ◽  
Author(s):  
Filippo Maggi ◽  
Vladislav Kolarčik ◽  
Pavol Mártonfi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chromosome Number ◽  
Pollen Grains ◽  
Pollen Size ◽  
Palynological Analysis ◽  
Positive Correlation ◽  
Pollen Characters ◽  
Scanning Electron

AbstractPollen size and exine structure of the following five Onosma L. species from Slovakia and Italy were studied by light and scanning electron microscopy: Onosma echioides, O. tornensis, O. visianii, O. arenaria, and O. pseudoarenaria. Among the taxa studied, O. echioides has the smallest pollen grains in average (10.5–17.5 × 8.0–14.5 µm), and O. pseudoarenaria the largest grains in average (15.3–20.5 × 12.3–16.3 µm). Pollen grains of all 5 species are small sized, 3-syncolporate, subprolate, heteropolar, with ovate equatorial outlines and circular to rounded triangular polar outlines; the tectum is microechinate. A positive correlation is found between pollen size and chromosome number. The value of pollen characters for taxonomic purposes and the position of the taxa studied within the genus Onosma are discussed.

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