Growth conditions are more important than species origin in determining leaf pigment content of British plant species

Abstract

Summary This paper describes a study of 23 plant species native to the British Isles, to investigate the relative importance of growth conditions and ecological origin in determining the content and composition of the photosynthetic pigments (chlorophylls and carotenoids) within leaves. The species studied reflected a range of ecological types, from deep shade to full sun. Plants were grown in two light environments: high light (HL), filtered through a clear filter; and low light (LL), filtered through a neutral density filter which reduced total irradiance with enhanced far‐red. Plants grown at high irradiance contained more carotenoid per unit chlorophyll and showed a marked increase in xanthophyll cycle pigments relative to other carotenoids. Deep‐shade plants were slightly less responsive to changes in growth light conditions than plants native to less shaded locations. Intermediate sun/shade plants were slightly more responsive; however these differences were small compared with the extent of the response of all species to HL vs LL. The main conclusion is that that the light conditions to which the plants are exposed are more important than the genetic predisposition of those plants in determining the pigment content and composition of leaves.