Germination of Pollen Inside Anthers in Some Non-Cleistogamous Species

Pacini, Ettore; Franchi, Gian Gabriele

doi:10.1080/00087114.1982.10796925

Cited by 35 publications

(10 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Epipactis microphylla thus falls within the spectrum of species (cleistogamous as well chasmogamous) whose pollen germinates inside the anther, transiently or totally bypassing contact with the receptive stigma (Anderson 1980;Lord 1981;Pacini and Franchi 1982;Mayers and Lord 1984;Grilli Caiola et al 2000). In the Arabidopsis gametophytic mutant ''raring-to-go'' (Johnson and McCormick 2001), 20% of pollen grains, besides normal ones, precociously germinate before anther dehiscence.…”

Section: Discussionmentioning

confidence: 99%

Gynostemium micromorphology and pollination in Epipactis microphylla (Orchidaceae)

2006

View full text Add to dashboard Cite

Self-pollination conditions have been recorded frequently in local populations of the genus Epipactis, and structural modifications have sometimes been reported, supporting taxonomic recognition of new species. As part of a survey of gynostemium micromorphology of Italian Epipactis populations, we studied an Apennine population of Epipactis microphylla (Ehrh.) Sw. a species listed as autogamous but with residual allogamous characters. In this population we observed the tendency to perform pre-anthesis cleistogamy. However, self-pollination was not a consequence of modification in column morphology. Cryptic pollen germination occurred in anther thecae or in the clinandrium, bypassing any contact with the receptive stigma. Pollen germination started from the distal pool of the pollinium, close to the rostellum-viscidium, suggesting that the rostellum-viscidium may have a function in promoting pollen-tube growth. Germinated pollen was exposed at the anthesis.

show abstract

Section: Discussionmentioning

confidence: 99%

Gynostemium micromorphology and pollination in Epipactis microphylla (Orchidaceae)

2006

View full text Add to dashboard Cite

show abstract

“…Most members of Alismatales (except Tofieldiaceae and Aponogetonaceae) are characterized by succesive microsporogenesis (Furness & Rudall, ; Furness & Banks, ) often resulting in formation of tetragonal and decussate tetrads. Variations in tetrad types are described for Arum L. (Araceae; Pacini & Franchi, ), Arisaema Mart. (Araceae; Maheshwari & Khanna, ), Butomus L. (Butomaceae; Furness & Banks, ), Thalassia Banks ex K.D.Koenig (Hydrocharitaceae, Pettitt, ), Triglochin L. (including Lilaea Bonpl .…”

Section: Discussionmentioning

confidence: 99%

A developmental study of pollen dyads and notes on floral development inScheuchzeria(Alismatales: Scheuchzeriaceae)

et al. 2016

View full text Add to dashboard Cite

Scheuchzeria palustris, the only member of Scheuchzeriaceae, is unique among Alismatales in several characters, including flower‐subtending bracts with conspicuous laminas and pollen dispersed in permanent dyads. Earlier studies revealed unidirectional flower development in some monocots with massive flower‐subtending bracts, but not in Scheuchzeria. Permanent pollen or spore dyads are extremely rare among extant land plants and in no case have they been studied developmentally. The paper provides new data on flower development and the first description of pollen development in Scheuchzeria. Flowers are arranged in a closed raceme. Development of lateral flowers is unidirectional, with delayed initiation of abaxial tepals and stamens. Flowers are often trimerous and pentacyclic, but numerous deviations from this groundplan are observed. Dyad development is investigated from microspore mother cells to mature pollen and their germination by electron microscopy and cytochemical methods. Meiosis is successive. Tetrads are irregular (42%), tetragonal (35%), decussate (13%), linear (7%) and T‐shaped (3%). During the tetrad period, the microspores are surrounded by a callose special wall of different thickness. Disintegration of tetrads into two dyads takes place along the plane of the first cytokinesis, where the thickness of the callose wall is maximal. Pollen grains are held together in the dyads due to a simple fusion of tectal layers, this fusion takes place at the late tetrad period. Developmental data did not reveal any possible aperture sites in Scheuchzeria. This favours the hypothesis of complete loss and subsequent regain of apertures in the course of evolution of the ‘tepaloid clade’ of Alismatales.

show abstract

“…The extension of pollen tubes in D. biflorum was observed both in locules and also after the pollen had slid down slightly onto the stigmatic surface. In flowers of E. microphylla (cleistogamous and also chasmogamous species) pollen germinated inside the anther, transiently or totally bypassing contact with the receptive stigma [6,[12][13][14][15][16]. Bonatti et al [6] maintained that in cleistogamous and self-pollinated flowers, pollen tubes emerging from pollen grains retained in the locules were growing beneath the stigmatic surface layer.…”

Section: Discussionmentioning

confidence: 99%

Notes on the self-pollination in Dendrobium biflorum (Orchidales, Dendrobiinae)

Kowalkowska

Margońska

2012

Acta Soc Bot Pol

View full text Add to dashboard Cite

The conditions favouring self-pollination are determined for a species of Dendrobium Sw. A survey of gynostemium micromorphology in collected flowers of Dendrobium biflorum revealed two stages of a unique form of autogamy: on germination of pollen tetrads, pollen tubes reached the stigmatic region without the pollen being displaced from the anther locules. This is the first time for this type of autogamy to be reported in Dendrobium biflorum. Pollen grains germinated directly from the locules, bypassing the stigma or falling or sliding down onto the stigmatic surface. The pollen tubes were long and reached the stylar canal. On The Society Islands, differences in exposure of the habitats to weather conditions and altitude gradients influence both composition and form of the vegetation, as well as the occurrence of pollinators. The form of autogamy described here may be the usual method of pollination found on The Society Islands (and even the whole of French Polynesia), where suitable pollinators are absent and/or growth conditions stressful

show abstract

Germination of Pollen Inside Anthers in Some Non-Cleistogamous Species

Cited by 35 publications

References 19 publications

Gynostemium micromorphology and pollination in Epipactis microphylla (Orchidaceae)

Gynostemium micromorphology and pollination in Epipactis microphylla (Orchidaceae)

A developmental study of pollen dyads and notes on floral development inScheuchzeria(Alismatales: Scheuchzeriaceae)

Notes on the self-pollination in Dendrobium biflorum (Orchidales, Dendrobiinae)

Contact Info

Product

Resources

About