Contribution of fern gametophytes to the growth of produced sporophytes on the basis of carbon gain

Sporophytes appeared on most gametophytes of Thelypteris palustris (Salisb.) Schott that reached a certain size, which is interpreted to be a critical size of gametophytes for the production of sporophytes. After sporophytes were produced, attached gametophytes ceased dry weight growth, but the gametophytes which did not produce sporophytes grew successively. It was hypothesized that matter produced by gametophytes was being supplied to young sporophytes. Photosynthesis and respiration of gametophytes with attached sporophytes were not significantly different from that of gametophytes without sporophytes. Photosynthetic activity of gametophytes dropped from 0.18 to 0.03 μmol CO2 g−1 s−1 during the growth period. The higher photosynthetic rates of gametophytes in the early growth stage were important for reaching the critical size for sporophyte production in a short time. Sporophytes in the ‘one leaf stage’ averaged 0.14 μmol CO2 g−1 s−1 of photosynthetic activity. The results show that sporophytes that had expanded the first leaf grow by their own photosynthetic production. Gametophytes allocated the photosynthate for sporophytes and it was an important aid before the one-leaf stage. The supportive role of gametophytes ended at that stage.

[1]  C. Haufler,et al.  Modes and mechanisms of speciation in pteridophytes : Implications of contrasting patterns in ferns representing temperate and tropical habitats , 2000 .

[2]  C. Haufler.  Modes and Mechanisms of Speciation in Pteridophytes , 1997 .

[3]  W. B. Anderson,et al.  The sporophyte-gametophyte junction in the moss Acaulon muticum (Pottiaceae): early stages of development , 1996 .

[4]  C. Haufler,et al.  C3 Photosynthesis in the Gametophyte of the Epiphytic CAM Fern Pyrrosia Longifolia (Polypodiaceae) , 1995 .

[5]  K. Kikuzawa.  Leaf phenology as an optimal strategy for carbon gain in plants , 1995 .

[6]  By E. Sheffield.  ALTERNATION OF GENERATIONS IN FERNS: MECHANISMS AND SIGNIFICANCE , 1994 .

[7]  J. Bonnemain,et al.  Physiological Aspects of Sugar Exchange between the Gametophyte and the Sporophyte of Polytrichum formosum. , 1992, Plant physiology.

[8]  T. J. Cooke,et al.  The Growth Forms of Developing Fern Gametophytes: a Theoretical Consideration of Form and Function Relationships , 1988 .

[9]  P. Nobel,et al.  Influences of PAR, temperature and water vapor concentration on gas exchange by ferns , 1984 .

[10]  J. Proctor,et al.  Effect of frond age on frond elongation, gas exchange, and water relations in the ostrich fern (Matteuccia struthiopteris) , 1984 .

[11]  J. Proctor,et al.  Effect of Water Stress on Gas Exchange in Fronds of the Ostrich Fern (Matteuccia struthiopteris (L.) Todaro) , 1983 .

[12]  J. A. Freeberg,et al.  Photosynthetic Rates of Sporophytes and Gametophytes of the Fern, Todea barbara. , 1980, Plant physiology.

[13]  D. Farrar.  Gametophytes of Four Tropical Fern Genera Reproducing Independently of Their Sporophytes in the Southern Appalachians , 1967, Science.

[14]  P. Bell,et al.  Changes in the Level of the Protein Nitrogen during Growth of the Gametophyte and the Initiation of the Sporophyte of Dryopteris borreri Newm. , 1961 .

[15]  R. Wetmore,et al.  MORPHOGENETIC STUDIES ON THE FERN TODEA BARBARA. III. EXPERIMENTAL EMBRYOLOGY , 1961 .

[16]  Johnh . Miller,et al.  THE EFFECT OF DIFFERENT LIGHT CONDITIONS AND SUCROSE ON THE GROWTH AND DEVELOPMENT OF THE GAMETOPHYTE OF THE FERN, ONOCLEA SENSIBILIS , 1961 .

[17]  T. Steeves,et al.  THE INDUCTION OF APOGAMY IN THE BRACKEN FERN , 1960 .

[18]  R. Böhning,et al.  THE EFFECT OF LIGHT INTENSITY ON RATE OF APPARENT PHOTOSYNTHESIS IN LEAVES OF SUN AND SHADE PLANTS , 1956 .

[19]  H. Albaum.  NORMAL GROWTH, REGENERATION, AND ADVENTITIOUS OUTGROWTH FORMATION IN FERN PROTHALLIA , 1938 .

[20]  D. M. Mottier.  Behavior of Certain Fern Prothallia under Prolonged Cultivation , 1927, Botanical Gazette.

[21]  D. M. Mottier.  Polyembryony in Certain Polypodiaceae and Osmundaceae , 1925, Botanical Gazette.

[22]  F. L. Pickett.  SOME ECOLOGICAL ADAPTATIONS OF CERTAIN FERN PROTHALLIA—CAMPTOSORUS RHIZOPHYLLUS LINK., ASPLENIUM PLATYNEURON OAKES , 1914 .