Androcymbium. – Allozymes

CASTELLS & JOAN PEDROLA

CASTELLS & JOAN PEDROLA

CASTELLS & JOAN PEDROLA

GENETIC STRUCTURE AND SPATIAL DISTRIBUTION OF A NARROW
ENDEMIC PLANT: ANDROCYMBlUM EUROPAEUM (LANGE) K. RICHTER
(COLCHICACEAE) SUMMARY Allozyme differentiation at 10 loci was used to ascertain, by means of the application of the conventional mathematical methods to assess gene frequency data, the manner in which the genetic variability of A. europaeum is structured in all its known populations. In spite of its conditions of narrow, threatened and endangered endemic plant, it shows no sign of genetic depauperation, having been clearly able to maintain very high levels of variation. A conception to determine allelic rarity was used in an attempt to establish relations of ancestrality between the populations. These relations were further substantiated by the data concerning the paleontologlcal history of the distribution area. Genetic and morphological divergence in the Androcymbium gramineum complex (Colchicaceae)
JOAN PEDROLA-MONFORT and JULI CAUJAPÉ-CASTELLS Abstract: Narrow endemism is a poor predict
or of genetic potential in the six taxa that conform the Androcymbium gramineum complex, as shown by the unexpectedly high values of variability associated with ten allozymic loci and 13 biometrical variables. Although both levels are shown not to be correlated, variability is always concentrated within populations. This result, together with environmental, reproductive and historical data strongly suggests differentiation in local isolates, where changes can be quickly assimilated by stochastic processes. A key implication for conservation is that sampling within the largest population will save effort while neglecting only very low frequency alleles. Morfología y anatomía foliar del complejo Androcymbium gramineum (sect. Erythrostictus Benth., Colchicaceae) MATEU-ANDRÉS, I., J. PEDROLA & J. GÜEMES Candollea 51: 203-214. (1996)
Resumen Se estudian y describen las características morfológicas y anatómicas de los ferófilos de las especies que forman el complejo Androcymbium gramineum de la sección Erythrostictus Benth. (A. gramineum, A. europaeum, A. palaestinum, A. rechingeri, A. wyssianum, A. hierrense, A. psammophilum). Son plantas con cormo tunicado, expansiones foliares que se destacan del tallo a diferentes alturas y dan lugar a nomófilos e hipsófilos con flores dispuestas sobre la parte media
de la lámina. El número de ferófilos, así como su tamaño y coloración resultan buenos caracteres diferenciales. Referente a la anatomía, los ferófilos presentan epidermis anfistomáticas, de células

prismáticas, y mesófilo formado por 6-9 capas de células, con idioblastos secretores de mucopolisacáridos azufrados. Abstract Morphological and anatomical characters of leaf structures of the species included in the
Androcymbium gramineum complex of section Erythrostictus Benth. are studied and described (A. gramineum, A. europaeum, A. palaestinum, A. rechingeri, A. wyssianum, A. hierrense, A. psammophilum). These plants have a tunicated corm, with leaves expansions detached from the stem at different sites, giving rise to nomophylls and hypsophylls with flowers on the central area of the lamina. Ferophylls number size and colour arc good diagnostic features. In reference to anatomy, ferophylls have an epidermis of prismatic cells, stomata on both the upper and the lower surface of the blade, Space-time patterns of genetic structure within a stand of Androcymbium gramineum (Cav.) McBride (Colchicaceae) JULI CAUJAPÉ-CASTELLS & JOAN PEDROLA-MONFORT Heredity 79: 341-349 (1997)

Space-time patterns of genetic structure in the largest known Spanish stand of Androcymbium gramineum were explored through spatial autocorrelation on allele frequencies at 17 allozymic loci. Our results strongly suggest that the consistent overall profiles of short-distance genetic structure detected have evolved in a scenario of prolonged habitat uniformity by the action of prolific vegetative reproduction overlaid with a minor incidence of outcrossing and self-fertilization. Investigation of the temporal component of spatial genetic structure through the assessment of differently aged cohorts of plants provided evidence that patch sizes in this stand are progressively enlarged in the absence of microhabitat differentiation. These results explain the maintenance of large amounts of variability in this endangered endemic species.