Physiological aspects of stress in Sesleria Caerulea (L) ard

Abstract

Sesleria caerulea is a wide ranging species, growing over a large altitudinal range. It varies spatially in both morphological and physiological characteristics. Responses to stress are characterised by an increase in proline production, but the ability to respond is not consistent for all populations. Edaphic factors are important in determining the nature of the response to cold stress, but if edaphic factors are standardized, proline production can be correlated with altitude plants at high elevations accumulate more proline than those from lower elevations. Edaphic factors are more important than climatic factors in determining the plant's ability to respond to drought stress. Plants growing in shallow soils produce more proline than those of deep soils, and are therefore more drought tolerant. The ability to produce proline appears to be maintained through out the plant's life, with no significant difference between the quantities of proline produced in the apical and basal halves of leaf blades. In the one case studied, the leaf form of Sesleria caerulea appeared to be an adaptation of the plant to a particular environment, rather than a genotypic characteristic. It is possible that some physiological responses are also not genotypic.