PATTERNS OF VARIATION IN ONTARIO WILD RICE (ZIZANIA-AQUATICA L) .4. INFLUENCE OF REGIONAL AND LOCAL ENVIRONMENTAL-FACTORS ON VARIATION WITHIN AND AMONG FIELD POPULATIONS

Analyses of covariance were used to examine morphological and productivity data from 17 indigenous wild rice populations in six empirically defined climatic regions. Statistical compensation for effects of local environmental factors (principal components of sediment nutrient concentrations, water depth and other emergent macrophytes) permitted direct comparisons of populations in different regions. there was a general trend of increasing stem and root weight, leaf width, and pistillate floret number with decreasing climatic severity. Tiller production was greatest in populations from intermediate climatic regimes. These results were consistent with those obtained in greenhouse experiments. Seed length and weight did not appear to be systematically related to climatic regime, and plant height was primarily a function of local environmental factors, especially water depth. © 1990.