INVESTIGADORES
SEIJO jose guillermo
artículos
Título:
Meiotic behavior and pollen viability of tetraploid Arachis glabrata and A. nitida species (Section Rhizomatosae, Leguminosae): implications concerning their polyploidy nature and seed set production
Autor/es:
A. ORTIZ; J.G. SEIJO; A. FERNÁNDEZ; LAVIA, G.
Revista:
PLANT SYSTEMATICS AND EVOLUTION
Editorial:
SPRINGER WIEN
Referencias:
Lugar: Viena :?.; Año: 2011 vol. 292 p. 73 - 83
ISSN:
0378-2697
Resumen:
Abstract The meiotic behavior and pollen viability of the
tetraploids (2n = 4x = 40) Arachis glabrata and A. nitida
were analyzed aiming to provide insights into the nature of
these polyploids and into the mechanism that determines
the low seed production of these species. Meiotic analysis
revealed 21 different chromosome configurations at diakinesis-
metaphase I in A. glabrata (from 20 II to 4 II ? 8 IV)
and 7 in A. nitida (from 20 II to 2 I ? 12 II ? 2 III ? 2
IV). The multivalent associations (up to 8 IV) observed in
some A. glabrata metaphases suggest that this species may
have an autopolyploid origin. However, the fact that the
mean number of bivalents varied among accessions indicates
different degrees of diploidization among them. In
contrast, the multivalents (up to 2 III ? 2 IV) observed in
very low frequency in A. nitida indicate that this species
may be either a largely diploidized autopolyploid or a
segmental allopolyploid. A great diversity, although in low
frequency, of meiotic abnormalities (abnormal chromosome
orientation and segregation, chromosome bridges,
irregular spindles, micronuclei, aneuploid nuclei, restitution
nuclei, microcytes, monads, dyads, triads, and hexads)
was detected in both species. The meiotic indexes were
over 95%, and pollen viabilities ranged from 83.20 to
95.99%. These results suggest that chromosome behavior
during meiosis would not severely affect pollen viability.
Thus, the irregular chromosome behavior caused by the
autopolyploid or segmental allopolyploid nature of these
species may not be related to their low seed set production.