Stoffwechselphysiologische Charakterisierung der Boraginaceen unter besonderer Berücksichtigung ökologischer Aspekte

Abstract

It is well established that morphological and anatomical plasticities are accompanied by physiological plasticity (E pstein & J efferies 1964). There have been several attempts to describe and classify plants by physiological data. One resulted in the "physiotype-concept" of Kinzel (1972), who described a "physiotype" as the pattern of specific physiological properties common to a certain taxonomic unit. The Austrian species of the Boraginaceae have been investigated by analytical methods to work out, whether there exists physiological plasticity with respect to different ecological habitats within this plant family. The plants were collected at natural habitats and divided into 4 groups according to their ecological behaviour. The mineral ions, organic acids, carbohydrates and free amino acids have been estimated. Additionally, the component of the mucilage which is responsible for the "hard cell saps" (H ofmeister 1940) has been analysed. Cluster analysis has been applicated to the data using "UPGMA" and "single linkage clustering method". By use of the presented physiological data the plant species could not be assigned to the 4 ecological groups. Water soluble pectin, the main component of the mucilage, is functioning as anion and therefore part of the ion-balance. The quantity of water soluble pectin shows no significant differences at the 4 types of habitats, whereas arnrnoniumoxalate soluble - mostly cell wall bound - pectin is accumulated at dry sites. An interesting connection between cyclitols, uronic acids and fructans has been estimated and their possible role in adaption to different habitats is discussed. D-Bomesitol is proposed to act as "compatible solute" in these species. The family represents an uniform "physiotype".