Variation in seed characters in populations of Vaccinium § Cyanococcus (the Blueberries) in relation to latitude

Abstract

Variation in seed characters of 22 populations of 8 largely allopatric species of Vaccinium [V. boreale, V. Darrowii, V. myrsinites, V. corymbosum, V. angustifolium, V. pallidum, V. tenellum, V. myrtilloides] sect. Cyanococcus (blueberries) was examined in relation to latitude. Seeds collected from open-pollinated berries representing populations in eastern North America from southern Florida [USA] (27.degree. N) to northern Newfoundland [Canada] (50.degree. N) were grown under glass 45.degree. N in uniform conditions. Seeds used in the analysis were obtained from the mature palnts and any variation they exhibited was presumed to be genetically rather than environmentally induced. Significant negative correlations between latitude and seed weight, seed coat thickness, time required for seed set and time required for germination are described. Since latitude is a gross indicator of climate, these correlations may be interpreted when climatic parameters such as growing season are related to the different phenologies of northern and southern species.