New Zealand Journal of Botany abstracts
Limiting factors of reproductive success in Bromus auleticus (Poaceae).
2. Fruit set under different pollination regimes, pollen viability, and
incompatibility reactions
Hugo F. Gutiérrez
Cátedra de Botánica Sistemática
Agronómica
Facultad de Ciencias Agrarias
Universidad Nacional del Litoral (UNL)
Luis Kreder 2805
(3080) Esperanza, provincia de Santa Fe, Argentina
hgutierr@fca.unl.edu.ar
Diego Medan
Cátedra de Botánica Agrícola
Facultad de Agronomía UBA
Av. San Martín 4453
(1417) Buenos Aires, Argentina
José F. Pensiero
Cátedra de Botánica Sistemática
Agronómica
Facultad de Ciencias Agrarias
Universidad Nacional del Litoral (UNL)
Luis Kreder 2805
(3080) Esperanza, provincia de Santa Fe, Argentina
Abstract Several aspects related to the
reproductive biology of the valuable Argentinian native forage grass Bromus
auleticus were studied in three populations to identify its
reproductive system and the factors that limit its reproductive
success. In vitro pollen fertility and germinability were
measured, and the behaviour of pollen tubes under self-pollination was
compared with that of cross-pollen. Fruit set under different
pollination conditions was also determined. Pollen amount and pollen
fertility do not per se limit fruit set, and pollen fertility
was not impaired by bagging; however, in vitro pollen
germination was low (22.5%) which may limit reproduction. The
differential behaviour of pollen tubes under selfing and crossing, as
well as the high pollen:ovule ratio, indicate allogamy. Substantial
fruit set (38.3%) occurred only when stigmas received nonself pollen in
adequate amounts. Treatments providing only self- or no pollination
drastically reduced or suppressed fruit set, which suggests lack of
apomixis and, at the same time, the operation of a self-incompatibility
mechanism. The limited reproductive success of a natural population of
this species may be the consequence of self-incompatibility coupled
with reduced genetic variation for incompatibility alleles.
Keywords reproductive success; fruit set; Bromus
auleticus; Poaceae; self-incompatibility
B05032; Received 25 July 2005; accepted 6 January 2006; Online
publication date 2 March 2006
New Zealand Journal of Botany, 2006, Vol. 44: 57–63
0028–825X/06/4401–0057 © The Royal Society of New Zealand 2006
PDF file of entire paper: Print-quality
(262K) | screen-quality (330K)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
