Population Differentiation and Plastic Responses to Drought Stress in the Generalist Annual Polygonum persicaria

We tested the generalist annual plant Polygonum persicaria (Polygonaceae) for adaptive differentiation in drought responses. Populations from one consistently moist and two variably dry sites were grown in moist and drought conditions in a greenhouse. Physiological, morphological, and reproductive data were collected. All three populations maintained similar levels of fitness in both drought and moist conditions, indicating that these populations may be equally drought tolerant. Also, the three populations had similar water use efficiency and root biomass responses to soil moisture, indicating that substantial phenotypic plasticity is present in all the populations, including a population from a consistently moist site. The magnitude of plastic responses for specific traits varied among the populations; i.e., the physiological and morphological means by which these plants maintained reproductive homeostasis across moisture conditions was population dependent. In particular, the moist‐site population had the greatest plasticity in water use efficiency, while the dry‐site populations had greater plasticity in root biomass allocation. Selection analyses demonstrated that increased water use efficiency was adaptive in drought and that decreased root biomass allocation was adaptive in moist conditions. Overall, the maintenance of fitness in stressful conditions may involve population differentiation along different axes of functional plasticity.

[1]  A. Sugden.  ECOLOGY/EVOLUTION: Phenotypic Plasticity , 2004 .

[2]  K. Donohue,et al.  Life-history variation and adaptation in the historically mobile plant Arabidopsis thaliana (Brassicaceae) in North America. , 2004, American journal of botany.

[3]  M. Geber,et al.  Inheritance and Natural Selection on Functional Traits , 2003, International Journal of Plant Sciences.

[4]  J. Craine,et al.  Covariation in leaf and root traits for native and non-native grasses along an altitudinal gradient in New Zealand , 2003, Oecologia.

[5]  P. Martre,et al.  Root deployment and shoot growth for two desert species in response to soil rockiness. , 2002, American journal of botany.

[6]  J. Schmitt,et al.  Population Differentiation and Natural Selection for Water‐Use Efficiency in Impatiens capensis (Balsaminaceae) , 2002, International Journal of Plant Sciences.

[7]  S. Sultan,et al.  Metapopulation Structure Favors Plasticity over Local Adaptation , 2002, The American Naturalist.

[8]  N. Hausmann,et al.  Population Differentiation for Abscisic Acid Responsiveness in Impatiens capensis (Balsaminaceae) , 2001, International Journal of Plant Sciences.

[9]  J. Schmitt,et al.  ADAPTIVE DIVERGENCE IN PLASTICITY IN NATURAL POPULATIONS OF IMPATIENS CAPENSIS AND ITS CONSEQUENCES FOR PERFORMANCE IN NOVEL HABITATS , 2001, Evolution; international journal of organic evolution.

[10]  S. Sultan.  Phenotypic plasticity for fitness components in Polygonum species of contrasting ecological breadth , 2001 .

[11]  Burt,et al.  Natural selection in the wild. , 2000, Trends in ecology & evolution.

[12]  S. Scheiner,et al.  MEASURING NATURAL SELECTION ON PHENOTYPIC PLASTICITY , 1999, Evolution; international journal of organic evolution.

[13]  Johanna Schmitt,et al.  Effects of Red to Far‐Red Ratio and Plant Density on Biomass Allocation and Gas Exchange in Impatiens capensis , 1999, International Journal of Plant Sciences.

[14]  D. L. Bell,et al.  Dynamic phenotypic plasticity for root growth in Polygonum: a comparative study. , 1999, American journal of botany.

[15]  D. L. Bell,et al.  Physiological response to complex environments in annual Polygonum species of contrasting ecological breadth , 1998, Oecologia.

[16]  S. Sultan,et al.  Contrasting ecological breadth of co‐occurring annual Polygonum species , 1998 .

[17]  D. Wilson,et al.  Costs and limits of phenotypic plasticity. , 1998, Trends in ecology & evolution.

[18]  H. Lambers,et al.  Relative growth rate, biomass allocation pattern and water use efficiency of three wheat cultivars during early ontogeny as dependent on water availability , 1996 .

[19]  S. A. Dudley.  DIFFERING SELECTION ON PLANT PHYSIOLOGICAL TRAITS IN RESPONSE TO ENVIRONMENTAL WATER AVAILABILITY: A TEST OF ADAPTIVE HYPOTHESES , 1996, Evolution; international journal of organic evolution.

[20]  David G. Williams,et al.  Ecophysiology of Introduced Pennisetum Setaceum on Hawaii: The Role of Phenotypic Plasticity , 1995 .

[21]  J. Ehleringer,et al.  Potential for selection on plants for water‐use efficiency as estimated by carbon isotope discrimination , 1994 .

[22]  R. Emery,et al.  Phenotypic plasticity of stem elongation in two ecotypes of Stellaria longipes: the role of ethylene and response to wind , 1994 .

[23]  J. Dubcovsky,et al.  Phenotypic plasticity and contrasting habitat colonization in Festuca pallescens , 1993 .

[24]  R. N. Mack,et al.  Ecological genetics of Bromus tectorum , 1991, Oecologia.

[25]  R. N. Mack,et al.  Ecological genetics of Bromus tectorum , 1991, Oecologia.

[26]  D. Soltis,et al.  Genetic variation in Bromus tectorum (Poaceae) : population differentiation in its North american range , 1991 .

[27]  T. Dawson,et al.  Genetic variation in and covariation between leaf gas exchange, morphology, and development in Polygonum arenastrum, an annual plant , 1990, Oecologia.

[28]  M. Lechowicz,et al.  Functional Interactions among Traits that Determine Reproductive Success in a Native Annual Plant , 1990 .

[29]  M. Lechowicz,et al.  VARIATION AMONG POPULATIONS OF XANTHIUM STRUMARIUM (COMPOSITAE) FROM NATURAL AND RUDERAL HABITATS , 1989 .

[30]  J. McGraw.  Experimental ecology of Dryas octopetala ecotypes , 1987, Oecologia.

[31]  R. Lande,et al.  GENOTYPE‐ENVIRONMENT INTERACTION AND THE EVOLUTION OF PHENOTYPIC PLASTICITY , 1985, Evolution; international journal of organic evolution.

[32]  K. Parkinson.  A simple method for determining the boundary layer resistance in leaf cuvettes , 1985 .

[33]  F. Bazzaz,et al.  EFFECTS OF SHORT-TERM SELECTION ALONG ENVIRONMENTAL GRADIENTS ON VARIATION IN POPULATIONS OF AMARANTHUS RETROFLEXUS AND ABUTILON THEOPHRASTI' , 1984 .

[34]  S. J. Arnold,et al.  THE MEASUREMENT OF SELECTION ON CORRELATED CHARACTERS , 1983, Evolution; international journal of organic evolution.

[35]  Alastair H. Fitter,et al.  Environmental physiology of plants , 1982 .

[36]  H. A. Gleason,et al.  Manual of Vascular Plants of Northeastern United States and Adjacent Canada. , 1963 .

[37]  J. Ehleringer,et al.  Contrasting water-use patterns among size and life-history classes of a semi-arid shrub , 1992 .

[38]  N. Moran,et al.  The Evolution of Aphid Life Cycles , 1992 .

[39]  P. V. Tienderen.  Morphological variation in Plantago lanceolata : limits of plasticity , 1990 .

[40]  Robert W. Pearcy,et al.  Plant Physiological Ecology , 1989, Springer Netherlands.

[41]  I. R. Cowan.  Economics of carbon fixation in higher plants , 1986 .

[42]  F. Bazzaz.  Life History of Colonizing Plants: Some Demographic, Genetic, and Physiological Features , 1986 .

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

[44]  A. D. Bradshaw,et al.  Evolutionary Significance of Phenotypic Plasticity in Plants , 1965 .