Cytological studies in the genus Azolla.

Nayak, S. K.; Singh, Pawan Kumar

doi:10.1508/cytologia.54.275

Cited by 11 publications

(5 citation statements)

References 11 publications

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“…7b), indicating the possible functional divergence between EAN1 and EAN2. Such a scenario is similar to that observed in tomato, in which, although a tandem duplication led to two subfamily II genes MALE STERILE 32 (MS32) (Solyc01g081100) and Solyc01g081090, single mutations of the MS32 induced abnormal tapetum development and Lu et al, 2011), Azolla filiculoides (Duncan, 1940;Nayak & Singh, 1989) and Selaginella moellendorffii (Schulz et al, 2010;Aya et al, 2011), the male antheridia of hornwort Anthoceros sp. (Johri & Srivastava, 2013;Villarreal et al, 2017), moss Physcomitrella patens (Landberg et al, 2013;Sanchez-Vera et al, 2017), liverwort Marchantia polymorpha (Koi et al, 2016;Yamaoka et al, 2018) and charophyte Chara braunii (Nishiyama et al, 2018), and the male gamete of chlorophyte Chlamydomonas reinhardtii (Johri & Srivastava, 2001).…”

Section: Origin and Evolution Of Tapetum And The Bhlh-mediated Degene...supporting

confidence: 71%

“…(d) Diagrammed sections illustrate the male sex organ structures of the representative species across eight major taxonomic groups. The Medicago truncatula anther section is based on the present study and the others are based on the following references: the microsporangia of Ginkgo biloba (Lu et al ., 2011), Azolla filiculoides (Duncan, 1940; Nayak & Singh, 1989) and Selaginella moellendorffii (Schulz et al ., 2010; Aya et al ., 2011), the male antheridia of hornwort Anthoceros sp. (Johri & Srivastava, 2013; Villarreal et al ., 2017), moss Physcomitrella patens (Landberg et al ., 2013; Sanchez‐Vera et al ., 2017), liverwort Marchantia polymorpha (Koi et al ., 2016; Yamaoka et al ., 2018) and charophyte Chara braunii (Nishiyama et al ., 2018), and the male gamete of chlorophyte Chlamydomonas reinhardtii (Johri & Srivastava, 2001).…”

Section: Discussionmentioning

confidence: 99%

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A study of male fertility control in Medicago truncatula uncovers an evolutionarily conserved recruitment of two tapetal bHLH subfamilies in plant sexual reproduction

Zheng

Liu

et al. 2020

New Phytologist

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Male sterility is an important tool for plant breeding and hybrid seed production. Male-sterile mutants are largely due to an abnormal development of either the sporophytic or gametophytic anther tissues. Tapetum, a key sporophytic tissue, provides nutrients for pollen development, and its delayed degeneration induces pollen abortion. Numerous bHLH proteins have been documented to participate in the degeneration of the tapetum in angiosperms, but relatively little attention has been given to the evolution of the involved developmental pathways across the phylogeny of land plants. A combination of cellular, molecular, biochemical and evolutionary analyses was used to investigate the male fertility control in Medicago truncatula. We characterized the male-sterile mutant empty anther1 (ean1) and identified EAN1 as a tapetum-specific bHLH transcription factor necessary for tapetum degeneration. Our study uncovered an evolutionarily conserved recruitment of bHLH subfamily II and III(a + c)1 in the regulation of tapetum degeneration. EAN1 belongs to the subfamily II and specifically forms heterodimers with the subfamily III(a + c)1 members, which suggests a heterodimerization mechanism conserved in angiosperms. Our work suggested that the pathway of two tapetal-bHLH subfamilies is conserved in all land plants, and likely was established before the divergence of the spore-producing land plants.

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Section: Origin and Evolution Of Tapetum And The Bhlh-mediated Degene...supporting

confidence: 71%

Section: Discussionmentioning

confidence: 99%

A study of male fertility control in Medicago truncatula uncovers an evolutionarily conserved recruitment of two tapetal bHLH subfamilies in plant sexual reproduction

Zheng

Liu

et al. 2020

New Phytologist

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“…These morphological distinctions are also corroborated by the reported chromosome counts: A. nilotica has a diploid karyotype of 2n = 52 (Stergianou & Fowler, 1989Saunders & Fowler, in press), whereas A . pinnata has 2n = 44 (Loyal, 1958(Loyal, , 1975Loyal et al, 1982;Singh et al, 1984;Nayak & Singh, 1989;Stergianou & Fowler, 1989Saunders & Fowler, in press). Azolla nilotica has a very simple nomenclatural history, with no synonyms.…”

Section: Interspecijic Variationmentioning

confidence: 99%

“…Palaeobot. Palyn.,39 : 1 1 1 (1983); Ashton 349 CHROMOSOME NUMBER: n = 22 (Loyal, 1958); 2n = 44 (Loyal, 1975;Loyal et al, 1982;Singh et al, 1984;Nayak & Singh, 1989;Stergianou & Fowler, 1989Saunders & Fowler, in press 39: 185 (1925). A .…”

Section: Intraspecijic Variationmentioning

confidence: 99%

A morphological taxonomic revision of Azolla Lam. section Rhizosperma (Mey.) Mett. (Azollaceae)

Saunders

Fowler

1992

Botanical Journal of the Linnean Society

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SAUNDERS, R. M. K. & FOWLER, K., 1992. A morphological taxonomic revision of Azolla Lam. section Rhizosperma (Mey.) Mett. (Azollaceae). Recent research on the agronomically important aquatic fern Azolla has been hampered by the lack of a sound taxonomic framework. The classification of section Rhizosperma is revised using multivariate statistical analyses of ultrastructural, gross morphological and anatomical characters. The disparate morphologies and current delimitations of A. pinnata and A. nilotica are corroborated. Three distinct geographically related subspecies of A. pinnata are identified and formally named and described as: 1. subsp. pinnata, occurring in northern and eastern Australia and New Caledonia; 2. subsp. asiatica subsp. nov., occurring in India, southern China, south‐east Asia and southern Japan; and 3. subsp. africana stat. et comb, nov., occurring in tropical Africa and Madagascar. A sequential dichotomous key is provided for the identification of taxa, with new taxonomic descriptions.

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“…In P. vittate and in C. cylindrothrix anaphase bridges were noticed but the frequency of these happenings seemed to be negligible. In Azolla filiculoides, Nayak and Singh (1989) observed precocious movement of anaphase chromosomes in few cells. The diploid chromosome numbers of A. capillus-veneris, A. caudatum and A. lunulatum were found to be 60, in Pteris species it was 58 whereas it was 72 in Ampelopteris and Christella except C. dentata which possessed 144 as 4x (Table 2).…”

Section: Resultsmentioning

confidence: 97%

Interphase Nuclear Structure in Ten Species of Pteridophytes

Mannan

Kabir

2021

J bio-sci.

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In thelypterids, interphase chromosomes of Ampelopteris prolifera were accompanied by two or three nucleoli. One nucleolus was seen floating outside the nucleus while other remained attached with the nucleus in annular cells of Christella arida. The mean of chromocentres determined in Adiantum species ranged from 49.8 to 53.6, whereas, it ranged from 46.6 to 49.5 in Pteris species. On the other hand, the value for chromocentres ranged from 62.5 to 123.5 in thelypterids. Nuclear organization was observed to be chromocentric type. In case of interphase nuclear volume it was observed that in Adiantum it was highest in A. capillus-veneris followed by A. caudatum and A. lunulatum, in Pteris it was highest in P. biaurita followed by P. vittata and P. griffithi, and in case of thelypterids, it was highest in C. dantata followed by C. Cylindrothix, A. Prolifera and C. arida. J. Bio-Sci. 29(2): 93-98, 2021 (December)

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Cytological studies in the genus Azolla.

Cited by 11 publications

References 11 publications

A study of male fertility control in Medicago truncatula uncovers an evolutionarily conserved recruitment of two tapetal bHLH subfamilies in plant sexual reproduction

A study of male fertility control in Medicago truncatula uncovers an evolutionarily conserved recruitment of two tapetal bHLH subfamilies in plant sexual reproduction

A morphological taxonomic revision of Azolla Lam. section Rhizosperma (Mey.) Mett. (Azollaceae)

Interphase Nuclear Structure in Ten Species of Pteridophytes

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