Phenotypic plasticity in Diplotaxis erucoides

Diplotaxis erucoides is a wide-spread mediterranean weed, which exhibit high levels of phenotypic plasticity in its center of distribution. This is especially true for those traits showing adaptation to saisonal climatic changes such as flowering time, lef morphology and leaf/stem anatomy. It has been shown that on Sicily several different phenotypes co-occur on the same arable fields. The consequence is, that also the soil seed bank represents seeds from all of these phenotypes. The populations are characterized by mesophytic subpopulations (occuring during the winter season with higher humidity and lower temperatures) and xerophytic subpopulations (during the summer season with low humidity and high temperatures). The question arise, if the soil seed bank reflects the differentiation of the actual vegetation and if the soil seed bank serves as a genetic buffer. For this purpose several populations from the center of the distribution range will be analysed considering individuals from the aboveground subpopulations as well as from the soil seed bank comprising all of the different phenotypes. A combination of different methods will be applied: morphometry, reproductive analysis, anatomical studies, germination experiments, genetic analyses using molecular techniques such as DNA analysis (AFLPs) and isozyme analysis.

Diplotaxis erucoides is a wide-spread mediterranean weed, which exhibit high levels of phenotypic plasticity in its center of distribution. This is especially true for those traits showing adaptation to saisonal climatic changes such as flowering time, lef morphology and leaf/stem anatomy. It has been shown that on Sicily several different phenotypes co-occur on the same arable fields. The consequence is, that also the soil seed bank represents seeds from all of these phenotypes. The populations are characterized by mesophytic subpopulations (occuring during the winter season with higher humidity and lower temperatures) and xerophytic subpopulations (during the summer season with low humidity and high temperatures). The question arise, if the soil seed bank reflects the differentiation of the actual vegetation and if the soil seed bank serves as a genetic buffer. For this purpose several populations from the center of the distribution range will be analysed considering individuals from the aboveground subpopulations as well as from the soil seed bank comprising all of the different phenotypes. A combination of different methods will be applied: morphometry, reproductive analysis, anatomical studies, germination experiments, genetic analyses using molecular techniques such as DNA analysis (AFLPs) and isozyme analysis.