Gametophytes of homosporous ferns

Nayar, B. K.; Kaur, Surjit

doi:10.1007/bf02859157

Cited by 263 publications

(295 citation statements)

References 142 publications

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“…Nevertheless, in A. nivea, as is has been stated by Atkinson (1973) for several genera of the Pteridaceae, it is difficult or impossible to determine the original position of the meristem looking to the adult gametophytes. Within cheilantoid ferns, Ceratopteris model of vegetative development seems to be infrequent, appearing in Astrolepis and Argyrochosma (Nayar & Bajpai 1963), and in Notholaena, Hemionitis and some Cheilanthes (Nayar & Kaur 1971).…”

Section: Discussionmentioning

confidence: 99%

Gametophyte development and reproduction of Argyrochosma nivea (Pteridaceae)

Galán

2010

Biologia

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The gametophyte of Argyroschosma nivea was studied, mainly focusing in its morphological development, and in the apogamous production of sporophytes. Some observations on the spores were also made. As far as it is known, this is the second species of the genus whose gametophytes are studied. The germination pattern followed the Vittaria type. The subsequent developmental processes followed the Ceratopteris type. Some of the gametophytes reached an adult stage with a cordate, symmetric shape, but most of them developed as irregular, lobed prothalli. The sporophyte emerged from the anterior part of the prothallus, without formation of gametangia. First, a cell became active and originated a proliferating area of small cells. From this area, long glandular hairs were formed followed by a projected conical cluster of cells. The cluster elongated into a sporophytic structure and its apex became progressively spatulate and finally trilobulate, with marginal, glandular hairs, stomata and tracheids continuously produced. This sporophyte secreted granules of white farina from its beginnings. The production of farina in the sporophyte but not in the gametophyte could help to support the idea of the segregation of this species from its traditional location in Notholaena to Argyrochosma, as farinose gametophytes seem to be a synapomorphy of the notholenoids, group that includes Notholaena but not Argyroschoma.

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Section: Discussionmentioning

confidence: 99%

Gametophyte development and reproduction of Argyrochosma nivea (Pteridaceae)

Galán

2010

Biologia

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“…El patrón de germinación de las esporas de ambas especies es del tipo Vittaria definido por Nayar & Kaur (1971), el más común entre los helechos homospóreos, según los mismos autores. Atendiendo a este patrón de desarrollo, la primera célula protálica, y por tanto el subsiguiente filamento, se forma de manera perpendicular al primer rizoide aparecido antes.…”

Section: Discussionunclassified

Gametófitos de Pleurosorus papaverifolius (Kunze) Fée (Aspleniaceae) y Cheilanthes glauca (Cav.) Mett. (Pteridaceae), dos helechos rupícolas sudamericanos

Galán

Prada

2009

Acta Bot. Bras.

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RESUMO -(Gametófitos dePleurosorus papaverifolius (Kunze) Fée (Aspleniaceae) e Cheilanthes glauca (Cav.) Mett. (Pteridaceae), dois fetos rupestres sul-americanos). O objetivo deste trabalho foi estudar a germinação de esporos, o desenvolvimento morfológico dos gametófitos e a expressão sexual de dois pteridófitas sul-americanos rupestres: Pleurosorus papaverifolius (Kunze) Fée. e Cheilanthes glauca (Cav.) Mett. Os esporos mostraram uma germinação vigorosa, e foram alcançadas percentagens relativamente altas de germinação (>70%) em menos de três semanas. Pleurosorus papaverifolius desenvolveu uma fase filamentosa de crescimento lento, com células grossas e inchadas que davam ao gametófito um aspecto algo arredondado; de forma contrária, em Cheilanthes glauca esta etapa foi efémera e rapidamente se passou à fase laminar. As formas pré sexuais tinham o aspecto cordado em ambas as espécies, mas em Pleurosorus papaverifolius desenvolveram-se, além disso, abundantes protalos alargados de maior tamanho. Enquanto que os protalos de Cheilanthes glauca foram não tricomados, os de Pleurosorus papaverifolius apresentaram numerosos tricomas unicelulares tanto marginais como superficiais. Ambos os pteridófitas se diferenciaram também na sua expressão sexual, que começou com o desenvolvimento de anterídios em Pleurosorus papaverifolius e de arquegónios em Cheilanthes glauca. Em Pleurosorus papaverifolius nunca se observaram gametófitos femininos, mas sim abundantes bissexuais. Cheilanthes glauca manteve durante muito tempo um número similar de gametófitos femininos e masculinos, produzindo unicamente um reduzido número de protalos bissexuais. Palavras-chave: Cheilanthes, Gametófitos, Pleurosorus, rupestre, Sul-américa RESUMEN -(Gametófitos de Pleurosorus papaverifolius (Kunze) Fée (Aspleniaceae) y Cheilanthes glauca (Cav.) Mett. (Pteridaceae), dos helechos rupícolas sudamericanos). En este trabajo se estudia la germinación de la espora, el desarrollo morfológico de los gametófitos y la expresión sexual de dos pteridófitos sudamericanos rupícolas: Pleurosorus papaverifolius (Kunze) Fée. y Cheilanthes glauca (Cav.) Mett. Las esporas mostraron una germinación vigorosa, y se alcanzaron porcentajes relativamente altos de germinación (>70%) en menos de tres semanas. Pleurosorus papaverifolius desarrolló una fase filamentosa de lento crecimiento, con células gruesas e hinchadas que daban al gametófito un aspecto algo redondeado; por el contrario, en Cheilanthes glauca esta etapa fue efímera y rápidamente se dio paso a la fase laminar. Las formas presexuales fueron cordadas en ambas especies, pero en Pleurosorus papaverifolius se desarrollaron, además, abundantes protalos alargados de mayor tamaño. Mientras que los protalos de Cheilanthes glauca fueron desnudos, los de Pleurosorus papaverifolius presentaron numerosos tricomas unicelulares tanto marginales como superficiales. Ambos pteridófitos difirieron también en su expresión sexual, que comenzó con el desarrollo de anteridios en Pleurosorus papaverifolius y de arquegonios en Cheila...

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“…The spores began to germinate 7-12 days after they were sown. Germination of the spore is of Aspidium-type following the definition of Nayar & Kaur (1971). The mature gametophytes were heart-shaped with unicellular papillate hairs on both surface and margin.…”

Section: Reproductive Mode and Spore Number/sporangiummentioning

confidence: 99%

First insights into the evolutionary history of the <I>Davallia repens</I> complex

Chen¹,

Ngan²,

Hidayat³

et al. 2014

Blum - J Plant Tax and Plant Geog

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Davallia repens and its close relatives have been identified as a species complex in this study because of the existence of continuously morphological variation. To decipher its evolutionary history, integrated methodologies were applied in this study including morphology, cytology, reproductive biology and molecular phylogeny. Analysis of morphological characters reveals several important discriminating characteristics, such as the shape of stipe scales, frond and indusium. Both diploid and polyploid forms are present in the complex and reproduce sexually and by apogamy, respectively. The incongruence between cpDNA and nDNA phylogeny indicates a hybrid origin for most polyploid individuals. Based on the present results, we hypothesize that there were at least two ancestral lineages distributed in the Malesian region. Through hybridization, polyploidization and apogamy, some polyploid genotypes dispersed outwards to shape the extant distribution.

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Gametophytes of homosporous ferns

Cited by 263 publications

References 142 publications

Gametophyte development and reproduction of Argyrochosma nivea (Pteridaceae)

Gametophyte development and reproduction of Argyrochosma nivea (Pteridaceae)

Gametófitos de Pleurosorus papaverifolius (Kunze) Fée (Aspleniaceae) y Cheilanthes glauca (Cav.) Mett. (Pteridaceae), dos helechos rupícolas sudamericanos

First insights into the evolutionary history of the <I>Davallia repens</I> complex

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