Genetic analysis of ecological relevant morphological variability in Plantago lanceolata L.

Summary Plants of an F₂ generation derived from crosses between two ecotypes of Plantago lanceolata L. had previously been studied in a greenhouse. In the present experiment, F₂ plants were transplanted into their original habitats (a hayfield and a pasture). Six allozyme loci were used as markers in the analysis of survival and performance of the segregating genotypes. Fitness differences between the plants were large enough to detect natural selection. In both transplantation sites selection appeared to operate, though in different ways. In the hayfield habitat directional selection was hypothesized and both survival and performance of the plants were related to genotype, with the genotypes originating from the hayfield almost always performing better. In the pasture habitat where the habitat is not uniform and unpredictable hazardous droughts occur, survival was nearly genotype independent and environmentally determined, whereas performance of the plants was genotype dependent. The expression of two morphological characteristics, number of leaves and leaf length, was often not in concordance with the greenhouse results and was contradictory in both sites. Expression of both characters in the field, therefore, appeared to be strongly dependent on the general performance and growth conditions of the plant and not on the genotype.Grassland Species Research Group Publication no. 143