Across latitudinal gradients, environmental conditions that influence plant growth and reproduction largely change. Here we study clonal variation in life-cycle characteristics of the cosmopolitan water plant Potamogeton pectinatus L. across a broad latitudinal range. Two consecutive experiments were performed under standardised laboratory conditions (photoperiod, irradiance and temperature). In the first experiment we investigated asexual reproduction among fifteen clones, obtained from latitudes ranging from 24 to 68° N. After 90 days of growth, high-latitude clones produced more but smaller tubers, while the aboveground biomass was lower as compared to the clones obtained from low latitudes. In a second experiment we studied inherent differences in early growth, morphology and photosynthesis for eleven clones (obtained from the same latitudinal range as in experiment 1). We found high among clonal variation for most measured variables, but the number of latitude-correlated traits was limited. The only trait that correlated with latitude was the number of leaves per plant, which increased in clones from higher latitudes. Our results agree with the hypothesis of a latitude-correlated switch in life-cycle strategy for this species. For northern clones this results in a short life-cycle, with an early and high investment in tuber biomass, while for low latitude clones the length of the life-cycle is prolonged, with a delayed reproduction and increased total plant biomass. [KEYWORDS: Asexual reproduction, Growth rate, Latitude, Morphology, Photosynthesis]
Original languageEnglish
JournalPlant Ecology
Journal publication date2003

ID: 249641