Culture of Azolla filiculoides in artificial conditions

Plant Biosystems (Impact Factor: 1.91). 11/2009; 2009(143):431–434. DOI: 10.1080/11263500903172110

ABSTRACT Azolla filiculoides showed a planar development in four culture media, but with overlapping of sporophytes after 28 days, and curled roots in all cases except for IRRI2. The difference in biomass between the media IRRI2 and IRRI1-Fe10x was statistically significant at Days 14, 21 and 28 by ANOVA. Medium IRRI2 gave the highest duplication time.

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    ABSTRACT: SummaryThe effect of varying concentrations of nitrate (2.5-15 mmol/L) has been studied in two species of the water fern Azolla in terms of their relative growth rate, heterocyst frequency of the symbiont Anabaena azollae, free ammonia, and activity of ammonia-assimilating enzymes. Both species showed optimum growth rate with 2.5 mmol/L of nitrate. Suppression of cyanobacterial heterocyst frequency occurred at relatively higher levels (15 mmol/L) of nitrate. Ammonium content released in nitrate treated plants increased sharply during later periods (7-14th day) of incubation. Invariably, all dosages of nitrate activated glutamine synthetase activity at 24 h in A. pinnata, while no significant change in this enzyme activity was observed in A. microphylla during this period. Further prolongation of treatment, up to the 14th day, resulted in suppression of this enzyme in both the species of Azolla with all levels of nitrate. Glutamate dehydrogenase enzyme exhibited more activities with higher concentrations of nitrate (≥ 10 mmol/L) in A. pinnata and lower dosages (≤ 5 mmol/L) in A. microphylla during later periods of incubation.
    Journal of Plant Physiology 01/2001; · 2.77 Impact Factor
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    ABSTRACT: Abstract Biomass increase, C and N content, C2H2 reduction, percentage dry weight and chlorophyll a/b ratios were determined for clones of Azolla caroliniana Willd., A. filiculoides Lam., A. mexicana Presl., and A. pinnata R. Br. as a function of nutrient solution, pH, temperature, photoperiod, and light intensity in controlled environment studies. These studies were supplemented by a glasshouse study. Under a 16 h, 26°C day at a light intensity of 200 μmol m−2 s−1 and an 8 h, 19° C dark period, there was no significant difference in the growth rates of the individual species on the five nutrient solutions employed. Growth was comparable from pH 5 to pH 8, but decreased at pH 9. Using the same photoperiod and light intensity but constant growth temperatures of 15–40°C, at 5°C intervals, the individual species exhibited maximum growth, nitro-genase (N2ase) activity and N content at either 25° or 30°C. There was no difference in the temperature optima at pH 6 and pH 8. The tolerance of the individual species to elevated temperature was indicated to be A. mexicana> A. pinnata> A. caroliniana> A.filiculoides. At the optimum temperature, growth rates increased with increasing photoperiod at both pH 6 and pH 8 but N2ase activity was usually highest at a 16 h light period. At photon flux densities of 100, 200, 400 and 600 μmol m−2 s−1, during a 16 h light period and optimum growth temperature of the individual species, N2ase activity was saturated at less than 200 μmol m−2 s−1 and growth at 400 μmol m−2 s−1.No interacting effects of light and pH were noted for any species, nor were light intensities up to 1700 μmol m−2 s−1 detrimental to the growth rate or N content of any species in a 5 week glasshouse study with a natural 14.5 h light period and a constant temperature of 27.5°C. Using the optimum growth temperature, a 16 h light period, and a photon flux density of at least 400 μmol m−2 s−1, the Azolla species all doubled their biomass in 2 days or less and contained 5–6% N on a dry weight basis.
    Plant Cell and Environment 04/2006; 3(4):261 - 269. · 5.91 Impact Factor
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    ABSTRACT: Study was conducted on six different Azolla species, available in the germplasm collection of NCCUBGA, IARI, New Delhi namely A. filiculoides, A. mexicana, A. microphylla, A. pinnata, A. rubra and A. caroliniana in a polyhouse to assess their growth potential by determining their maximal biomass productivity, doubling time and relative growth rates. Their nitrogen fixing potential was assessed by acetylene reduction assay. Among them Azolla microphylla gave highest biomass production and relative growth rate followed by Azolla caroliniana. Both these had high nitrogenase activity also. Peak nitrogenase activity of these strains was found on 14th day of growth and it declined on further incubation. Azolla microphylla and Azolla rubra were more tolerant to salinity than others. On the other hand Azolla pinnata, which is endemic species found in India, exhibited low biomass production, relative growth rate and lower nitrogenase activity compared to other species. It was unable to sustain growth in saline medium. Under polyhouse conditions, A. microphylla was found to perform better than other cultures in terms of biomass productivity, N fixing ability and salt tolerance. Hence it is taken up for mass production.
    Biomass and Bioenergy 03/2003; 24(3):175-178. · 3.41 Impact Factor


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Jun 5, 2014