THE EFFECT OF SPECIFIC VARIABILITY AND THE ENVIRONMENT ON THE VITAMIN C CONTENT OF BRITISH ROSE HIPS.

Abstract

SUMMARY. 1 The vitamin C content of the hip flesh of fourteen British Rose species was determined by the dye titration method. 2 The mean vitamin C content ranged from 75 mg. per cent in R. arvensis to 1303 mg. per cent in R. mollis; variation within species and varieties was considerable. 3 No close correlation was found between vitamin C content and chromosome number. 4 Some evidence was found in favour of Chailakhyan's hypothesis that high vitamin content is associated with persistently erect sepals. 5 An apparent correlation between earliness of ripening and high vitamin content broke down when non-British roses were examined. 6 The rose populations of relatively acid soils provided slightly richer hips than those of basic soils, but the difference was not significant. 7 The vitamin C content of rose hip populations increased fairly regularly in passing from low to high latitudes, due to the localization of high yeilding species in the north and the poorer species in the south. No correlation could be demonstrated between vitamin C content and latitude within the species. 8 No significant evidence was found for an effect on vitamin content due to light intensity or length of day. 9 The fertility of the hips, measured by the proportion by weight of the achenes to total hip weight, was not correlated with vitamin C content and apparent correlations were due to specific differences in hip shape.