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Growth and survival of Azolla filiculoides in Britain. II. Sexual reproduction
Author(s) -
JANES RACHEL
Publication year - 1998
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.1998.00113.x
Subject(s) - biology , azolla , germination , sexual reproduction , botany , fern , biomass (ecology) , population , reproduction , asexual reproduction , spore , phosphorus , horticulture , agronomy , ecology , demography , sociology , materials science , metallurgy
Sporulation in the floating fern Azolla filiculoides Lam. is both frequent and widespread in Britain and might therefore play a greater part in the population dynamics of the species than has been suggested by earlier reports. In laboratory experiments, increasing plant density and/or phosphorus supply resulted in increased sporulation. It was estimated that a thick mat of 8 kg m 2 fresh biomass can produce 380000 microsporocarps and 85000 megasporocarps per m 2 . Light and temperatures >10°C were necessary for sporocarp germination. Sporocarps could survive exposure to both low temperatures (5°C for at least 3 months) and sub‐zero temperatures (−10°C for at least 18 d). Sporocarps were found to survive storage in water for 3 yr and to germinate from mud samples collected in the field. In laboratory culture, sporeling growth and survival were optimal at 15°C. There is some evidence that A. filiculoides might have adapted to the British climate since its introduction.