The Typhaceae comprise about 18 species of herbaceous plants within the single genus Typha which provide fibrous leaves used for matting and construction. The fruit is a dehiscent nutlet and the seeds show orthodox storage behaviour. Information on seed dormancy and germination is provided below.
TYPHA
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T. angustata Bory & Chaub. |
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T. angustifolia L. |
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T. domingensis (Pers.) Steud. |
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T. latifolia L. |
common cat-tail |
I. Evidence of dormancy
Seeds of Typha spp. can be very dormant. For example, seeds of T. latifolia remained dormant after between 2 and 3 years storage (5) and seed germination is reported to be low without specific treatments to remove dormancy (12).
II. Germination regimes for non-dormant seeds
T. angustifolia, T. domingensis
Constant temperatures: 24°C, 30°C, light, 100 fc (4)
T. latifolia
Constant temperatures: 21°C, 3w (12); 24°C, 30°C, light, 100 fc (4); 25°-30°C in light (9)
Alternating temperatures: 10°/32°C, 15°/32°C (18h/6h) (5); 15°/30°C, 15°/35°C, 20°/30°C, 20°/35°C (16h/8h) (9)
III. Unsuccessful dormancy-breaking treatments
T. angustata
Light: white, less than 100 lux (8); blue (8)
T. domingensis
Constant temperatures: 15°C, 20°C, 30°C (11)
T. latifolia
Constant temperatures: -11°C, 5°C, 21°C, 32°C (12); 10°C (1); 10°-38°C in dark (5); 15°C, 20°C, 30°C (11)
Alternating temperatures: 15°/27°C, 22°/32°C, 22°/38°C (18h/6h), dark (5)
Warm stratification: 21°C, 7d, then -11°C, 5°C, 7d, germinate at 21°C (12)
Light: far red, 5 min (1); dark (5,9); blue (9)
Oxygen: 21, 37% (6)
Storage: -11°C, 5°C, 7d (12)
Scarification: concentrated sulphuric acid, 1.5, 2 min (12); mechanical, abrasive sand, 15-45 min (12)
Removal of seed covering structures: puncture seed coat of moist seeds at pointed end (12)
IV. Partly-successful dormancy-breaking treatments
T. angustata
Light: white, 100 lux (8)
T. domingensis
Alternating temperatures: 10°/20°C, 20°/30°C (16h/8h) in light, 8h/d (11)
T. latifolia
Constant temperatures: 15°C, 30°C (1); 30°C, 35°C, low light irradiance (9); 37.5°C (12)
Alternating temperatures: 20°/30°C (16h/8h) in dark (9); 15°/35°C (16h/8h) in dark or light, low irradiance (9); 10°/20°C, 20°/30°C (16h/8h), light 8h/d (11)
Pre-chill: -11°C, 5°C, 7d (12)
Warm stratification: 22°C, 27°C, 32°C, 18d, germinate at 22°/32°C (18h/6h) in light (5); 21°C, 7d, then 5°C, 7d, germinate at 21°C (12)
Light: red, 9 J cm-2, 10h, after 6-24h dark (1); daylight (5) Removal of seed covering structures: prick (3)
Scarification: concentrated sulphuric acid, 20-80s (5); concentrated sulphuric acid, 0.5, 1 min (12)
Potassium nitrate: co-applied, 10-2, 2x10-2 M (5)
Oxygen: below 2.1% (6); 17-20% (6); 21% (9)
V. Successful dormancy-breaking treatments
T. latifolia
Constant temperatures: 30°C in light, seeds under water (9); 30°C, seeds under water, 2.3-4.3 mg/1 oxygen, red light, 9 J cm-2, 10h, after 6-24h dark (1)
Alternating temperatures: 20°/30°C (16h/8h) in light, low irradiance (9); 10°-21°/22°C (16h/8h) in light, 1.8x10-3 W cm-2 (10)
Removal of seed covering structures: (5,6,9); pericarp, remove or rupture (2); prick at embryo end (9); press blunt end of moist seeds with steel probe (12)
Oxygen: 2.1-16.8% (6); 2%, at 30°C in light (9)
VI. Comment
A high temperature (1), a low oxygen partial pressure (1,6,9), a low light irradiance (1,5,9), potassium nitrate (5), alternating temperatures (5,9), and the rupture of seed coats (2,6,12) are reported to be essential for promoting the germination of dormant seeds of Typha spp. Seeds with ruptured seed coats (pericarp) germinate over a wide range of temperatures (6). Consequently it is suggested that the seeds be imbibed in the dark, or under a low irradiance of light, for 24 hours and the pericarps of the moist seeds ruptured at the blunt - that is the embryo - end of the seed. Then test for germination on the top of filter papers moistened with 10-2 M potassium nitrate - use more filter papers than is usual to ensure sufficient moisture is available to the seeds throughout the test - in an alternating temperature regime of 20°/30°C (16h/8h) - since it is reported to be superior to 10°/30°C (11) - for 21 days or more with light, low irradiance, applied during the 8 hour periods spent at the higher temperature.
VII. References
1. Bonnewell, V.A. (1981). Typha productivity, mineral nutrition, and seed germination. Dissertation Abstracts International, B, 42, 10.
2. Crocker, W. (1907). Germination of seeds of water plants. Botanical Gazette, 44, 375-380.
3. Jackson, C.V. (1928). Seed germination in certain New Mexico range grasses. Botanical Gazette, 86, 270-294.
4. McNaughton, S.J. (1966). Ecotype function in the Typha community-type. Ecological Monographs, 36, 297-325.
5. Morinaga, T. (1926). Effect of alternating temperatures upon the germination of seeds. American Journal of Botany, 13, 141-158.
6. Morinaga, T. (1926). The favorable effect of reduced oxygen supply upon the germination of certain seeds. American Journal of Botany, 13, 159-166.
7. Morris, E.L. (1911). Germination of cat-tail seeds. Torreya, 11, 181-184.
8. Sharma, K.P. and Gopal, B. (1979). Effect of light intensity on seedling establishment and growth in Typha angustata Bory and Chaub. Pol. Arch. Hydrobiol., 26, 495-500.
9. Sifton, H.B. (1959). The germination of light-sensitive seeds of Typha latifolia L. Canadian Journal of Botany, 37, 719-739.
10. Thompson, K., Grime, J.P. and Mason, G. (1977). Seed germination in response to diurnal fluctuations of temperature. Nature, 267, 148-149.
11. Vasconcelos, T. (1981). [Germination of seeds of common reed (Phragmites australis (Cav.) Steudel) and cattails (Typha domingensis (Pers.) Steudel and T. latifolia L.).] I. Congresso Português de Fitiatria e de Fitofarmacologia e III Simposio Nacional de Herbologia, 1980, 3, 85-91. (From Seed Abstracts, 1982, 5, 2455.)
12. Yeo, R.R. (1964). Life history of common cattail. Weeds, 12, 284-288.
