Ultrastructure and cytochemistry of the hydrophilous pollen of Lepilaena (Zannichelliaceae)

McConchie, C. A.; Knox, R. B.; Ducker, Sophie C.

doi:10.1016/0047-7206(82)90048-6

Cited by 3 publications

(2 citation statements)

References 2 publications

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“…The only exception is Althenia (Potamogetonaceae), which was recently redefined to include Lepilaena (Ito et al, 2016). Earlier data on pollen of Australian Althenia (former Lepilaena ) were incomplete, but showed differences from Eurasian/African species (McConchie et al, 1982; Severova et al, 2020a). Here we used original data on two Australian species of Althenia .…”

Section: Methodsmentioning

confidence: 99%

Pollen in water of unstable salinity: Evolution and function of dynamic apertures in monocot aquatics

Severova

Rudall

Macfarlane³

et al. 2022

American J of Botany

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Premise: The sporoderm of seed-plant pollen grains typically has apertures in which the outer sporopollenin-bearing layer is relatively sparse. The apertures allow regulation of the internal volume of the pollen grain during desiccation and rehydration (harmomegathy) and also serve as sites of pollen germination. A small fraction of angiosperms undergo pollination in water or at the water surface, where desiccation is unlikely. Their pollen grains commonly lack apertures, though with some notable exceptions. We tested a hypothesis that in some angiosperm aquatics that inhabit water of unstable salinity, the pollen apertures accommodate osmotic effects that occur during pollination in such conditions. Methods: Pollen grains of the tepaloid clade of the monocot order Alismatales, which contains ecologically diverse aquatic and marshy plants, were examined using light microscopy and scanning electron microscopy. We used Ruppia as a model to test pollen grain response in water of various salinities. Pollen aperture evolution was also analyzed using molecular tree topologies. Results: Phylogenetic optimizations demonstrated an evolutionary loss and two subsequent regains of the aperturate condition in the tepaloid clade of Alismatales. Both of the taxa that have reverted to aperturate pollen (Ruppia, Ruppiaceae; Althenia, Potamogetonaceae) are adapted to changeable water salinity. Direct experiments with Ruppia showed that the pollen apertures have a role in a harmomegathic response to differences in water salinity. Conclusions: Our results showed that the inferred regain of pollen apertures represents an adaptation to changeable water salinity. We invoke a loss-and-regain scenario, prompting questions that are testable using developmental genetics and plant physiology.

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Section: Methodsmentioning

confidence: 99%

Pollen in water of unstable salinity: Evolution and function of dynamic apertures in monocot aquatics

Severova

Rudall

Macfarlane³

et al. 2022

American J of Botany

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“…and Nqjas tenuijiJlia (N ajadaceae), and in the terrestrial plants Liliumlongijlorum (Liliaceae) and Latium perenne (Gramineae). For the aquatic taxa considered here details of the male program of ontogeny are drawn primarily from the work of McConchie (1983), McConchie et al (1982) and McConchie and Knox (1987a, b). In these, and other submerged aquatic flowering plants, pollen ontogeny and pollination are highly specialized and have been the subject of numerous studies (Ducker and Knox, 1976;Ducker et al, 1978;Pettitt, 1976;Pettitt et al, 1980Pettitt et al, , 1981.…”

Section: Introductionmentioning

confidence: 99%

Phylogenetic Analysis of the Male Ontogenetic Program in Aquatic and Terrestrial Monocotyledons

Blackmore¹,

McConchie²,

Knox³

1987

Cladistics

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The male program of ontogeny in flowering plants encompasses the events from meiosis of microsporocytes to fertilization. Three main sequences are discussed; the deposition of cell walls, changes in cytoplasmic organelles, and the program of nuclear divisions leading to the formation of two sperm cells and a vegetative cell in each pollen grain. Variations in these ontogenetic sequences are particularly apparent in the monocotyledons, which exhibit diversity in pollen morphology, wall structure, and mode of pollination. The male program of development has been compared in selected terrestrial monocotyledons belonging to the Liliaceae and Gramineae and aquatic members of the Cymodoceaceae, Najadaceae, and Zannichelliaceae. A total of 26 characters from the male program are discussed and then used to construct a cladogram derived only from developmental data for the five species. The polarity of only a few of the character transformations has been determined directly by observation of developmental sequences; most have been interpreted by outgroup analysis.

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Systematics and Evolution of Australian Seagrasses in a Global Context

Waycott

Biffin

Les

2018

Seagrasses of Australia

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Ultrastructure and cytochemistry of the hydrophilous pollen of Lepilaena (Zannichelliaceae)

Cited by 3 publications

References 2 publications

Pollen in water of unstable salinity: Evolution and function of dynamic apertures in monocot aquatics

Pollen in water of unstable salinity: Evolution and function of dynamic apertures in monocot aquatics

Phylogenetic Analysis of the Male Ontogenetic Program in Aquatic and Terrestrial Monocotyledons

Systematics and Evolution of Australian Seagrasses in a Global Context

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