Bryophytes Amphibians of plant kingdom

1. BryophytesAmphibians of plant kingdom Dr. Maneesha Singh Assistant Professor, Department of Life Sciences SGRRITS, Patel Nagar, Dehradun, UK

2. Bryophyte • Bryophytes are small plants (2cm to 60cm) that grow in moist shady places. They don’t attain great heights because of absence of roots, vascular tissues, mechanical tissues and cuticle. They are terrestrial but require external water to complete their life cycle. • The division Bryophyta (Gr. bryon=moss) includes over 25000 species of non-vascular embryophytes such as mosses, liverworts and hornworts. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

3. Hence, they are called “Amphibians of plant kingdom”. • The fossil record indicates that bryophytes evolved on earth about 395 – 430 million years ago (i.e. during Silurian period of Paleozoic era). The study of bryophytes is called bryology. • Hedwig is called ‘Father of Bryology’. • Shiv Ram Kashyap is the ‘Father of Indian Bryology’. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

4. Salient features of Bryophytes: • Bryophytes grow in damp and shady places. • They follow heterologous haplodiplobiontic type of life cycle. • The dominant plant body is gametophyte on which sporophyte is semiparasitic for its nutrition. • The thalloid gametophyte differentiated in to rhizoids, axis (stem) and leaves. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

5. Embryo develop from outer cells: exoscopic. • Capsule produces haploid meiospores of similar types (homosporous). • Spore germinates into juvenile gametophyte called protonema. • Progressive sterilization of sporogenous tissue noticed from lower to higher bryophytes. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

6. List of important bryophytes Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

7. Classification of Bryophytes: • According to the latest recommendations of ICBN (International Code of Botanical Nomenclature), bryophytes have been divided into three classes: • Hepaticae ( Hepaticopsida = Liverworts) • Anthocerotae (Anthocertopsida= Hornworts) • Musci (Bryopsida= Mosses) Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

8. Class 1. Hepaticae or Hepaticopsida: • Gametophytic plant body is either thalloid or foliose. If foliose, the lateral appendages (leaves) are without mid-rib. Always dorsi-ventral. • Rhizoids without septa. • Each cell in the thallus contains many chloroplasts; the chloroplasts are without pyrenoid. • Sex organs are embedded in the dorsal surface. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

9. Sporophyte may be simple (e.g. Riccia) having only a capsule, or differentiated into root, seta and capsule (e.g., Marchantia, Pellia and Porella etc.) • Capsule lacks columella. • It has 4 orders: • Calobryales • Jungermanniales • Spherocarpales • Marchantiales. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

10. Riccia Porella Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

11. Riccia, with sporophyte (right) embedded in gametophyte (left) Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

12. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

13. Class 2. Anthocerotae or Anthocerotopsida: • Gametophytic plant body is simple, thalloid, thallus dorsiventral without air chambers, shows no internal differentiation of tissues. • Scales are absent in the thallus. • Each cell of the thallus possesses a single large chloroplast with a pyrenoid. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

14. Sporophyte is cylindrical only partly dependent upon gametophyte for its nourishment. It is differentiated into bulbous foot and cylindrical capsule. Seta is meristematic. • Endothecium forms the sterile central column (i.e., columella) in the capsule (i.e. columella is present). 6. It has only one order-Anthocerotales. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

15. Anthoceros Megaceros Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

16. Notothylas Dendroceros Phaeoceros Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

17. Class 3. Musci or Bryopsida: • Gametophyte is differentiated into prostrate protonema and an erect gametophores • Gametophore is foliose, differentiated into an axis (=stem) and lateral appendages like leaves but without midrib. • Rhizoids multi-cellular with oblique septa. • Elaters are absent in the capsule of sporangium. • The sex organs are produced in separate branches immersed in a group of leaves. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

18. Classes of Mosses: • Bryidae- true mosses, Polytrichum. • Protonema with a single row of cells with slanted cross walls. • Leafy gametophytes develop from minute budlike structures. • Sphagnidae- peat mosses, Sphagnum. • Protonema with plate of cells that is one layer thick. • Gametophytes with clusters of branches, 5 per node. • Explosive capsular operculum. • Adreaeidae- granite mosses, Andreaea. • Protonema with 2 or more rows of cells. • Capsule dehisces by splitting in four. • Rhizoids occur in 2 rows. • Mountainous or arctic regions on rocks. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

19. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

20. Fossil bryophytes • First fossils found in Devonian (probable origin in Silurian or even Ordovician) • The oldest unequivocal bryophyte fossil is a liverwort – Pallavicinites (very similar to Pallavicinia, which we saw in lab), from upper Devonian (370 MYA) in New York state – probably have it here in Southern Ontario too. • Great liverwort flora in Jurassic/Triassic of Sweden (200+ MYA). Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

21. Fossil and extant pallavicinalean liverworts. 1. Pallavicinites devonicus, portion of thallus (from Oostendorp, 1987). 2. Pallavicinia xiphoides thallus (from Karssilov et al., 1984). Arrows indicate position of marginal teeth. vis-pc.plantbio.ohiou.edu/ moss/dunn1.html Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

22. Fossilized spores preserved in 440-470 million-year-old sediments afford the earliest evidence for plant life on land. Were the plants that produced them Bryophytes? Wellman, C., Osterloff, P.L. and Mohiuddin, U., 2003. Fragments of the earliest land plants. Nature, 425: 282-284. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

23. Bryophyte ecology and nutrition • Bryophytes, like lichens, may take in nutrients through “leafy” tissues of thallus, in addition to uptake through rhizoids and (in a few) via symbiosis with Glomeromycota • Because of this, they are sensitive to the environments where they live: some prefer acidic sites, others basic or calcium-rich sites; some are pollution intolerant, others tolerant • Saxicolous, corticolous, epiphyllous etc Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

24. Economic importance of Bryophytes: • Protection from soil erosion: Bryophytes, especially mosses, form dense mats over the soil and prevent soil erosion by running water. • Soil formation: Mosses are an important link in plant succession on rocky areas. They take part in binding soil in rock crevices formed by lichens. Growth of Sphagnum ultimately fills ponds and lakes with soil. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

25. Water retention: Sphagnum can retain 18-26 times more water than its weight. Hence, used by gardeners to protect desiccation of the seedling during transportation and used as nursery beds. • Peat: It is a dark spongy fossilized matter of Sphagnum. Peat is dried and cut as cakes for use as fuel. Peat used as good manure. It overcomes soil alkalinity and increases its water retention as well as aeration. On distillation and fermentation yield many chemicals. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

26. As food: Mosses are good source of animal food in rocky and snow-clad areas. • Medicinal uses: Decoction of Polytrichum commune is used to remove kidney and gall bladder stones. Decoction prepared by boiling Sphagnum in water for treatment of eye diseases. Marchantia polymorpha has been used to cure pulmonary tuberculosis. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

27. Other uses: Bryophytes arc used as packing material for fragile goods, glass wares etc. Some bryophytes act as indicator plants. For example, Tortell tortusa grow well on soil rich in lime. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS

28. Dr. Maneesha Singh, Assistant Professor, Department of Life Sciences, SGRRITS