POPULATION DIFFERENTIATION IN FESTUCA RUBRA L. AND AGROSTIS STOLONIFERA L. IN RESPONSE TO SOIL WATERLOGGING

Abstract

Summary Two populations of Agrostis stolonifera and seven populations of Festuca rubra from salt marsh and inland habitats were grown on a free draining soil and at two levels of soil waterlogging. The growth of A. stolonifera was stimulated by soil waterlogging while that of F. rubra was depressed. There was no difference between the two populations of A. stolonifera in growth response to waterlogging but the inland population had a greater Fe concentration in the shoots when grown on waterlogged soil than the salt marsh population. In F. rubra the yield of the salt marsh populations was generally less depressed by soil waterlogging than that of populations from free draining soils; the salt marsh populations also had lower concentrations of Fe and Mn in the shoot on the continuously waterlogged soil than the inland populations. It is concluded that the evolution of a degree of waterlogging tolerance has occurred in the salt marsh populations of F. rubra in response to the periodic flooding by sea water in their native habitats.

PHENOTYPIC FLEXIBILITY OF CAREX FLACCA SCHREB.

“…Similar differences have been detected below the species level, among populations within plant species collected from soils that vary in liability to flooding (e.g. Linehart & Baker, 1973;Keeley, 1979;Davies & Singh, 1983;Waldren, 1985;Etherington & Thomas, 1986).…”

“…Flooding increased transport of Mn to the shoot system but the Fe concentration in the shoots was identical in all three treatments, indicating that the additional Fe was immobilized in the roots. Jones (1972) found an almost identical distribution of Fe and Mn to that described here in C. fiacca grown in dune slack sand under various flooding regimes, whereas the grass species used in his study, Agrostis stolonifera and Festuca rubra, transported both additional Fe and Mn to the shoot, although this occurred to a lesser extent in populations of these species from flooded sites than in populations from freedrained soils (Davies & Singh, 1983).…”

“…Linehart & Baker, 1973;Keeley, 1979;Davies & Singh, 1983;Waldren, 1985). In the present study, however, all populations of C. fiacca were equally tolerant of soil flooding despite originating from sites which were very different in their liability to flooding (Table 1).…”

“…Soluble plus available Fe and Mn concentrations (mainly Fe^^ and Mn^^ in the flooded treatments) were determined in soil samples taken 50 mm below the soil surface and shaken in air-free ammonium acetate (1 mol dm~3) as described by Davies & Singh (1983). For convenience these are henceforward referred to as reduced Fe and Mn.…”

Abiotic modulation of Spartina maritima photobiology in different latitudinal populations

“…In this context, halophytes with a wide latitudinal distribution are likely to show intra-specific differences between partially and totally isolated populations (Àlvarez et al, 2010). Genetic differentiation among populations within a plant species is well documented, with certain populations being better adapted than others to specific environmental stressors (Keeley, 1979;Silander and Antonovics, 1979;Davies and Singh, 1983;Chung, 1989). This natural genetic variation provides the potential for selection of plant populations exhibiting improved stress tolerance.…”