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Notothylas by p.n

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priyankanagal

- Notothylas is a genus of hornworts classified in the division Bryophyta. It reproduces both sexually through spores and vegetatively through parts of the thallus. - The life cycle involves an alternation of generations between a thalloid gametophyte generation that produces gametes and a sporophyte generation that is bullet-shaped and produces spores. - Species of Notothylas are found worldwide in moist habitats and vary in characteristics of the thallus, sporophyte structure, and spore ornamentation. Rare species like N. yunannensis from China have unique traits that distinguish them from related species.

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SEMINAR TOPIC : NOTOTHYLAS Paper : Bot 104 MSc. Pre. 1st sem SUBMITTED BY : PRIYANKA NAGAL SUBMITTED TO : DR. SUNITA ARORA
NOTOTHYLAS POINTS TO BE DISCUSSED : • CLASSIFICATION • GENERAL CHARACTERS • REPRODUCTION • LIFE CYCLE
CLASSIFICATION: DIVISION : BRYOPHYTA CLASS : ANTHOCEROTOPSIDA ORDER : ANTHOCEROTALES FAMILY : NOTOTHYLACEAE
GENERAL CHARACTERS:- • Found in moist habitat. • Notothylas shows strong resemblance with Anthoceros. • The genus comprises a number of species which are widely distributed both in the tropics and temperate zones. • N. indica, N. levieri, N. chaudhurii and N. javanicus found in India. • It is the smallest hornwort, grows few centimeter. • It is also unusual among hornworts, its sporophyte is bullet shaped and of few millimeters in length.
THALLUS External Features:- • Rosette like thallus • Dorsiventral flat • Thin, delicate, smooth • Light yellowish • Toothed or entire irregular processes • Unicellular, smooth walled rhizoids • Scales and tuberculate rhizoids are absent. • On gametophyte, bullet shaped sporophytes arise at margins of thallu • No midrib seen
Internal structure:- • 6 to 8 layers of cell • Stomata present on lower epidermis • Mucilage cavities present at lower region of thallus forming slime pore opening. • In N. javanicus mucilage cavity is absent.
Reproduction:- 1.Vegetative -Death and decay thallus part -Bulbs -Tubers 2. Sexual -Production of meiospores. -Monoecious are strongly protoandrous.
Development of Antheridia:- • Occur in clusters of 2-6 in antheridial chambers. • Protoplast of each androcyte form a single biflagellate sperm.
Development of Archegonia:- • They are present close to the growing tip of the thallus. • 3-5 NCC wider than Anthoceros.
Fertilization:- • Oospore forms after fertilization. • Sporophytic generation begins.
SPOROPHYTE: • Sporophyte grows out horizontally from the fertile lobes usually in pairs, its length about 3mm and 0.5mm in diameter. • It totally dependent on gametophyte. • The first division in either transverse or vertical in zygote after fertilization. • In N. indica and N. levieri the sporogonium is completely enclosed within the involucre but N. javanicus and N. breutelii it slightly projected beyond it. • Supporter columella varies from species to species. • The pseudoelaters are simple, equal in size and longer than the spores, with spiral and obique bands.
Columellate sporogonium: • Entire endothecium forms the columella. • Amphithecium cells divide into inner and outer. • N. indica • N. orbicularis Non-columellate sporogonium: • Entire endothecium is fertile and forms archesporium. • N. choudhurii Intermediate species: • N. breutelii • N. javanicus
DEVELOPMENT: • Capsule wall is 3-4 layered thick and lacks stomata. • Sporogenous tissues around columella. • Sporogenous mass in mature one is differentiated into unicellular sterile cells and SMC. • SMC undergo meiosis to form spore tetrads with exospore and endospore.
spore germination: • Under favorable conditions the spore absorbs moisture and germinates. • Exospore ruptures and contents bulged out by small papilla. • Minute thallus form by first transverse and second in opposite direction with repeated cell division.
Life cycle:
Rare and peculiar hornworts: • N. yunannensis firstly reported in china- Yunnan, Thailand by T. Peng and R.L. Zhu in 2012 and this was accepted in 2014. • Its IUCN status is “Data Deficient” because of being small and ephermerial characters. • Its thalli is deep green, fascicular rosette, 7-15mm in diameter. • 1) the irregularly arranged, sub quadrate to sub rectangular epidermal cells the capsule, • 2) the absence of the special dehiscence lines of thick-walled cells. • 3) the vermiculate ornamentation of the spores radiating from a central hollow on each proximal surface (Peng and Zhu, 2014). • Notothylas yunannensis is closely related to Notothylas depressispora J. Haseg. Haseg. and N. irregularis Chantanaorr., which also has vermiculate spores with a small depression on each proximal facet.
References:- • “Botany for degree students Bryophyta” B.R. VASHISHTA, DR. A.K. SINHA, DR. ADAERSH KUMAR by S. Chand publications. • Rare and peculiar hornworts: Notothylas orbicularis and N. javanica (Notothyladaceae), new genus and species records for Australia. • Phytotaxa 275 (1): 001–013 http://www.mapress.com/j/pt/ 2016 • Note on Notothylas yunannensis (Notothyladaceae, Anthocerotophyta), a little known species of hornwort, Sirikanda Rattanamanee and Sahut Chantanaorrapint*, Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112 Thailand. • Received: 9 February 2015; Accepted:18 March 2015.
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Notothylas by p.n

  • 1. SEMINAR TOPIC : NOTOTHYLAS Paper : Bot 104 MSc. Pre. 1st sem SUBMITTED BY : PRIYANKA NAGAL SUBMITTED TO : DR. SUNITA ARORA
  • 2. NOTOTHYLAS POINTS TO BE DISCUSSED : • CLASSIFICATION • GENERAL CHARACTERS • REPRODUCTION • LIFE CYCLE
  • 3. CLASSIFICATION: DIVISION : BRYOPHYTA CLASS : ANTHOCEROTOPSIDA ORDER : ANTHOCEROTALES FAMILY : NOTOTHYLACEAE
  • 4. GENERAL CHARACTERS:- • Found in moist habitat. • Notothylas shows strong resemblance with Anthoceros. • The genus comprises a number of species which are widely distributed both in the tropics and temperate zones. • N. indica, N. levieri, N. chaudhurii and N. javanicus found in India. • It is the smallest hornwort, grows few centimeter. • It is also unusual among hornworts, its sporophyte is bullet shaped and of few millimeters in length.
  • 5. THALLUS External Features:- • Rosette like thallus • Dorsiventral flat • Thin, delicate, smooth • Light yellowish • Toothed or entire irregular processes • Unicellular, smooth walled rhizoids • Scales and tuberculate rhizoids are absent. • On gametophyte, bullet shaped sporophytes arise at margins of thallu • No midrib seen
  • 6. Internal structure:- • 6 to 8 layers of cell • Stomata present on lower epidermis • Mucilage cavities present at lower region of thallus forming slime pore opening. • In N. javanicus mucilage cavity is absent.
  • 7. Reproduction:- 1.Vegetative -Death and decay thallus part -Bulbs -Tubers 2. Sexual -Production of meiospores. -Monoecious are strongly protoandrous.
  • 8. Development of Antheridia:- • Occur in clusters of 2-6 in antheridial chambers. • Protoplast of each androcyte form a single biflagellate sperm.
  • 9. Development of Archegonia:- • They are present close to the growing tip of the thallus. • 3-5 NCC wider than Anthoceros.
  • 10. Fertilization:- • Oospore forms after fertilization. • Sporophytic generation begins.
  • 11. SPOROPHYTE: • Sporophyte grows out horizontally from the fertile lobes usually in pairs, its length about 3mm and 0.5mm in diameter. • It totally dependent on gametophyte. • The first division in either transverse or vertical in zygote after fertilization. • In N. indica and N. levieri the sporogonium is completely enclosed within the involucre but N. javanicus and N. breutelii it slightly projected beyond it. • Supporter columella varies from species to species. • The pseudoelaters are simple, equal in size and longer than the spores, with spiral and obique bands.
  • 12. Columellate sporogonium: • Entire endothecium forms the columella. • Amphithecium cells divide into inner and outer. • N. indica • N. orbicularis Non-columellate sporogonium: • Entire endothecium is fertile and forms archesporium. • N. choudhurii Intermediate species: • N. breutelii • N. javanicus
  • 13. DEVELOPMENT: • Capsule wall is 3-4 layered thick and lacks stomata. • Sporogenous tissues around columella. • Sporogenous mass in mature one is differentiated into unicellular sterile cells and SMC. • SMC undergo meiosis to form spore tetrads with exospore and endospore.
  • 14. spore germination: • Under favorable conditions the spore absorbs moisture and germinates. • Exospore ruptures and contents bulged out by small papilla. • Minute thallus form by first transverse and second in opposite direction with repeated cell division.
  • 16. Rare and peculiar hornworts: • N. yunannensis firstly reported in china- Yunnan, Thailand by T. Peng and R.L. Zhu in 2012 and this was accepted in 2014. • Its IUCN status is “Data Deficient” because of being small and ephermerial characters. • Its thalli is deep green, fascicular rosette, 7-15mm in diameter. • 1) the irregularly arranged, sub quadrate to sub rectangular epidermal cells the capsule, • 2) the absence of the special dehiscence lines of thick-walled cells. • 3) the vermiculate ornamentation of the spores radiating from a central hollow on each proximal surface (Peng and Zhu, 2014). • Notothylas yunannensis is closely related to Notothylas depressispora J. Haseg. Haseg. and N. irregularis Chantanaorr., which also has vermiculate spores with a small depression on each proximal facet.
  • 17. References:- • “Botany for degree students Bryophyta” B.R. VASHISHTA, DR. A.K. SINHA, DR. ADAERSH KUMAR by S. Chand publications. • Rare and peculiar hornworts: Notothylas orbicularis and N. javanica (Notothyladaceae), new genus and species records for Australia. • Phytotaxa 275 (1): 001–013 http://www.mapress.com/j/pt/ 2016 • Note on Notothylas yunannensis (Notothyladaceae, Anthocerotophyta), a little known species of hornwort, Sirikanda Rattanamanee and Sahut Chantanaorrapint*, Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, 90112 Thailand. • Received: 9 February 2015; Accepted:18 March 2015.