IBONE   05434
INSTITUTO DE BOTANICA DEL NORDESTE
Unidad Ejecutora - UE
artículos
Título:
Ploidy dimorphism and reproductive biology in Stenodrepanum bergii (Leguminosae), a rare South American endemism
Autor/es:
CAPONIO, I.; ANTON, A. M.; FORTUNATO, R.; NORRMANN, G.A.
Revista:
GENOME
Editorial:
NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS
Referencias:
Lugar: Otawa; Año: 2011 vol. 57 p. 1 - 7
ISSN:
0831-2796
Resumen:
Abstract: This is the first report on chromosome numbers and the reproductive behaviour in Stenodrepanum Harms, a rareendemic and monotypic legume genus from the arid and salty areas of central?western Argentina. Sixty individuals belongingto two populations from two salty areas (?salinas?) were surveyed and included mostly triploid (2n = 3x = 36) and onlytwo diploid (2n = 2x = 24) plants. Meiosis in diploids is regular, with bivalent pairing and uniform and viable pollen. Incontrast, meiosis in triploids is characterized by high trivalent pairing, with irregularly shaped pollen and variation in cytoplasmcontent and stainability, which is in agreement with an unbalanced segregation occurring in anaphases I and II. However,different triploid plants/individuals showed various degrees of pollen fertility, which may be attributed to particulargenotypes. Research on reproductive biology events indicates sexual cross-pollinated reproduction enhanced by protogyny inboth cytotypes. All plants produced seeds, but seedlings were only recovered from diploid plants pollinated with triploids,and even those eventually perished. Chromosome counts in these seedlings revealed aneuploid chromosome numbers owingto the combination of unbalanced gametes.