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Title: The biology of Molinia caerulea (L.) moench with special reference to population variation.
Author: Salim, Kamariah Abu.
ISNI:       0000 0001 3547 1097
Awarding Body: Manchester Polytechnic
Current Institution: Manchester Metropolitan University
Date of Award: 1989
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Molinia caerulea, the purple moor grass is widely distributed and morphologically variable. Its occurrence on well-drained Ca'+-rich alkaline Leblanc waste is unusual since the grass normally has a calcifuge habit and grows an wet acid peaty soils. Molinia is deciduous losing its leaves after the formation of an abscission zone. Leaf abscission in grasses is rare. This project aims, therefore, (a) to investigate the anatomy of leaf abscission in Molinia using scanning electron microscopy; (b) to quantify and explain morphological and biochemical differences which occur between two populations growing in contrasting habitats, namely acid moorland and Leblanc waste. Scanning electron microscopy of freeze fractured nodes of naturally senescing Molinia showed that leaf separation was due to separation of cells along the middle lamella, although some cells showed fractured cell walls. Molinia should prove an interesting model in which to study abscission process in the Gramineae. A comparative study of the two contrasting populations of Molinia was made. Twenty-four morphological characters were used to classify the Molinia. Multivariate analysis distinguished the two populations. Acid-moorland plants were characterised predominantly by vegetative features eg. leaf length, plant height. Whereas in alkaline-waste Molinia, flower morphology was most important eg. culm length, lemma length. There were differences in growth and flowering between the two populations. Differences in growth were maintained under constant conditions suggesting that endogenous factors were responsible. Classification using cluster analysis of proteins extracted from basal internodes separated by SDS-PAGE distinguished between the two populations. Analysis of isoenzyme patterns obtained from SGE and PAGE showed that variation within each population was greater than that between populations. There was thus no evidence of genetic differences between the two populations. Root-surface phosphatase activity of both field and laboratorygrown plants showed pH optima appropriate to the field environment of the roots. In laboratory grown plants, there was evidence that the enzyme activity responded to changes in pH but not calcium concentrations. Variability in Molinia populations involves both endogenous factors and phenotypically plastic modifications at both whole organism and molecular levels.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Botany