Outbreeding Challenged: Autogamy
and Apomixis, New Contenders in
Any accession that exhibited autogamy
or which did not have L.
lepidus is capable of autogamy
(in the presence of wind agitation) and a pollen addition experiment in 1991 provided no evidence for pollen limitation (J.
The final three traits, corolla length, flower width, and stigma-anther separation, were measured because they are likely to be important in the attraction of pollinators and in the probability of autogamy
. Stigma-anther separation is correlated with autogamy
rates across several taxa of Mimulus (Ritland and Ritland 1989), and an overall reduction in flower size is a common feature of selfing Mimulus species that are believed to be recently derived from outcrossing taxa (e.g., Macnair and Cumbes 1989; Ritland and Ritland 1989).
was recorded only among species of Tillandsia subgenus Diaphoranthema, characterized by neotenic species with a tendency toward polyploidy (Till, 1992).
 through  allow the estimation of [N.sub.e(v)] for species with a given rate s and can be extended to the extreme cases of panmixia (s = 0) or complete autogamy
(s = 1).
Although flowers set fruit following experimental pollination with pollen from the same individual (and are thus considered self-compatible; Munoz and Devesa 1987), autogamy
(i.e., within-flower pollination) rarely occurs in nature because of marked protandry.
The second plant was retained in case the first plant died, and to provide a second estimate of the autogamy
rate within each family.
10B) may have changed from insect pollinated to pure autogamy
, but autogamy
is not uncommon in this genus, so this failsafe system may even have facilitated establishment of colonizers.
Two of the five [F.sub.1] hybrids, HG276-7 (hybrid of G31276 [is greater than](AG-S4) and HG31721 (hybrid of G31317) [is less than] AG-S4), were chosen to produce [F.sub.2] seed without manipulation of flowers, i.e., by autogamy
. Backcross (BC) generations were obtained by crossing HG276-7 and HG317-21 to their respective parents to produc BC-R ([F.sub.1] hybrids )[is less than] Moroccan parent, where R designates a rhizomatous parent) and BC-NR ([F.sub.1] hybrids ) [is less than] AG-S4, where NR designates a nonrhizomatous parent) generations.
drummondii, Salmon Beauty, to selection for increased and decreased autogamy
. We specifically address the following questions: (1) To what extent can the self-compatible and self-incompatible breeding systems of the two wild species be altered by two cycles of artificial selection?
Early maturity, small flowers and autogamy
: A developmental connection?