Changes of Cyanogenic Glucosides in White Clover (<i>Trifolium repens</i>L.) during the Growing Season

Abstract

Cyanogenic glucosides have been determined in eight white clover cultivars during three growing seasons. Differences in total cyanogen content were found for different cultivars and also for the time of sampling during the vegetation season. A direct correlation was found between the total cyanogen content and mean air temperature for four days before sampling. At temperatures below 15 °C all varieties contained the highest cyanogen content; an increase in temperature during the summer time resulted in a drastic decrease in cyanogen synthesis. The linamarin/lotaustralin ratio ranged from 0.4 to 0.8 and was correlated with the total cyanogen content; cultivars with higher cyanogen level had a lower lin/lot ratio. It was concluded that white clover can be a good example of a plant species having a mechanism which can switch between growth-dominated and differentiation-dominated plant types depending on to the environmental conditions. Keywords: Cyanogenic glucosides; white clover; Trifolium repens; seasonal changes