Natural hybridization in Glandularia (Verbenaceae). Evolutionary impications of chromosome pairing

LIDIA POGGIO, SILVIA M. BOTTA, EDUARDO J. GREIZERSTEIN AND MARIAR. FERRARI

DARWINIANA

INSTITUTO DE BOTÁNICA DARWINION

Lugar: Buenos Aires; Año: 1993 vol. 32 p. 77 - 90

0011-6793

ABSTRACT: Poggio, L., Botta, S. M., Greizerstein, E. J. and Ferrari, M. K. 1993, Natural hy¬bridization in Glandularia (Verbenaceae). I. Evolutionary implications of chromosome pairing Darwiniana 32: 77-90 The morphology, distributional patterns of phenolic compounds and meiotic behaviour of sev¬eral individuals of G. incisa (Hook.) Trone, G. pulchella (Sweet) Tronc. and six natural putative hybrids from the province of Corrientes (Argentina) were analyzed. Both species belong to well-differentiated morphological groups and possess Taxon-specific chromatographic compounds. Pu¬tative hybrids are morphologically intermediate and their chromatograms show almost total ad¬dition of the compounds of the parental species. Two numerical techniques (principal component analysis and distance diagram) are congruent, and both show the intermediacy of the putative hybrids. Despite the morphological and chromatographical similarities of the hybrids, their meiotic behaviour presents highly significant differences in chain bivalents, circle bivalonts, univalents and chiasma frequency. The results obtained suggest that some genie combinations of parental species are more disharmonious than others. According to Jackson's (1984) model, the parental species would be polymorphic and/or polytypic for mutations that cause changes in the she of attachment of genome to the nuclear membrane. The ability of the chromosomes to pair in the F1 hybrids will depend on the distance of the nuclear site attachment of its two parental genomes, and pairing at the diploid level would be controlled by a relatively simple gene system.