Latitudinal variation in tuber production in an aquatic pseudo-annual plant, Potamogeton pectinatus

The effect of day length and latitude on the induction of tuberisation in Potamogeton pectinatus L. was investigated. Six clones originally collected at widely different latitudes (from 24°N in Egypt to 68°N in Russia) were used to test two hypotheses: (1) tuberisation is a short-day response, and (2) critical day length increases with increasing latitude. Plants sprouted from tubers of a standardised size (50–150 mg fresh weight) were allowed to grow for 56 days under long-day conditions (22 h light) and then transferred for 21 days to eight different day lengths (12, 13, 14, 15, 16, 18, 20 and 22 h light). While the frequency of tuberising plants was not significantly affected by day length, it increased from 2 to 87% with increasing latitude of origin. Other plant traits such as size at induction, biomass yield and biomass allocation were correlated with tuberisation frequency. However, none of them accounted for the correlation between tuberisation frequency and latitude. A comparable analysis on Hydrilla verticillata, using Steward's [Hydrobiologia 354 (1997) 571] data, showed that the induction and abundance of tuber and turion production increased with increasing latitude (N=23, range 3–40°, N and S latitudes pooled) and with decreasing day length (10 h versus 16 h). The effect of day length did not account for the positive correlation between tuber and turion production and the clone's latitude of origin of the clones. We thus conclude that there is a latitudinal trend towards an earlier onset of asexual reproduction in these two pseudo-annual plant species, which is not caused by variation in their response to day length. [KEYWORDS: Day length; Latitude; Asexual reproduction; Short-day response; Critical size]

[1]  F. Chapin,et al.  Ecotypic differentiation of growth processes in Carex aquatilis along latitudinal and local gradients. , 1981 .

[2]  C. Osmond,et al.  Physiological Plant Ecology I , 1981, Encyclopedia of Plant Physiology.

[3]  J. Suzuki,et al.  Latitudinal variation in plant size and relative growth rate in Arabidopsis thaliana , 1998, Oecologia.

[4]  G. Ksander,et al.  Influence of Photoperiod and Plant Weight on Tuber Production by Potamogeton pectinatus L. , 1993 .

[5]  D. Spencer,et al.  Influence of photoperiod on growth, pigment composition and vegetative propagule formation for Potamogeton nodosus Poir. and Potamogeton pectinatus L. , 1987 .

[6]  M. Stanton,et al.  CONSEQUENCES OF EMERGENCE PHENOLOGY FOR REPRODUCTIVE SUCCESS IN RANUNCULUS ADONEUS (RANUNCULACEAE) , 1991 .

[7]  H. G. Baker.  Seed Weight in Relation to Environmental Conditions in California , 1972 .

[8]  S. McNaughton.  r- and K-Selection in Typha , 1975, The American Naturalist.

[9]  W. V. Vierssen,et al.  Photoperiodic effects on photosynthesis and tuber production in Potamogeton pectinatus L. , 1994 .

[10]  J. Titus,et al.  Toward predicting reproductive success in submersed freshwater angiosperms , 1991 .

[11]  C. Fox,et al.  Maternal effects as adaptations , 1998 .

[12]  R. J. V. Wijk.  Ecological studies on Potamogeton pectinatus L. I: General characteristics, biomass production and life cycles under field conditions , 1988 .

[13]  A. Farmer,et al.  FLOWERING, GERMINATION AND ZONATION OF THE SUBMERGED AQUATIC PLANT LOBELIA DORTMANNA L. , 1987 .

[14]  P. Jordano,et al.  Geographical variation in seed production, predation and abortion in Juniperus communis throughout its range in Europe , 2000 .

[15]  P. Gorham,et al.  Turions and dormancy states in Utricularia vulgaris , 1979 .

[16]  G. Ksander,et al.  Field and greenhouse investigations on winter bud production by Potamogeton gramineus L. , 1994 .

[17]  G. E. Hutchinson,et al.  A treatise on limnology. , 1957 .

[18]  W. F. Millington,et al.  The biology of aquatic vascular plants , 1967 .

[19]  Jan E. Vermaat,et al.  Lake Veluwe, a Macrophyte-dominated System under Eutrophication Stress , 1994, Geobotany.

[20]  L. Santamaría,et al.  Latitudinal variation in life-cycle characteristics of Potamogeton pectinatus L.: vegetative growth and asexual reproduction , 2003, Plant Ecology.

[21]  H. Greppin,et al.  Evolution de l'activite auxines-oxydasique et peroxydasique lors de l'induction photoperiodique et de la sexualisation de l'epinard : , 1972 .

[22]  D. Spence,et al.  PHOTOCONTROL OF TURION FORMATION BY POTAMOGETON CRISPUS L. IN THE LABORATORY AND NATURAL WATER , 1985 .

[23]  C. H. Ward,et al.  Environmental and Chemical Control of Vegetative Dormant Bud Production in Hydrilla verticillata , 1984 .

[24]  K. K. Steward.  Influence of photoperiod on tuber production in various races of Hydrilla (Hydrilla verticillata) , 1997, Hydrobiologia.

[25]  O. M. Heide,et al.  Primary and Secondary Induction Requirements for Flowering of Contrasting European Varieties of Lolium perenne , 2000 .

[26]  J. Weiner,et al.  PLASTIC RELATIONSHIPS BETWEEN REPRODUCTIVE AND VEGETATIVE MASS IN SOLIDAGO ALTISSIMA , 1993, Evolution; international journal of organic evolution.

[27]  F. Woodward,et al.  The impact of low temperatures in controlling the geographical distribution of plants , 1990 .

[28]  O. Lange.  Responses to the physical environment , 1981 .

[29]  K. Gross,et al.  Latitudinal variation in seed weight and flower number in Prunella vulgaris , 1993, Oecologia.

[30]  W. Ernst,et al.  Fruit development and performance of Schoenus nigricans in coastal dune slacks of Europe: an extension of H. G. Baker's seed mass‐altitude to a seed mass‐latitude relationship , 1995 .

[31]  J. Weiner,et al.  The influence of competition on plant reproduction. , 1988 .

[32]  F. Salisbury.  Responses to Photoperiod , 1981 .