flowers produced 16% more seeds than naturally pollinated flowers (Table 3).
By transplanting metamorphs back to the field in 2009, I was also able to show that for those offspring that were able to complete metamorphosis, selfing resulted in decreased survival and reproductive fitness compared to outcrossed
controls (Table 4).
In both species, outcrossed
seeds are heavier, have higher germination frequency, higher growth rate, and lower risk of early seedling death than selfed seeds.
o] are the mean fitnesses of inbred and outcrossed
progeny calculated from the eight maternal sibmeans of each crosstype, respectively (cf.
Collectively, these findings suggest that outcrossed
pollen provided by pollinators is essential to maximize H.
Consequently, an increase in autogamous self-pollination may be achieved with little reduction of outcrossed
male fitness (Rausher et al.
This approach was developed to allow for a heterogeneous pollen pool and therefore discriminate between the intraspecific and interspecific fractions of the outcrossed
pollen (homogeneity of gamete pools is assumed in most mixed mating models; Fyfe and Bailey 1951; Ritland 1990).
We used the ratio between selfed produced progeny (fruits and seeds) and the value for outcrossed
produced progeny to estimate inbreeding depression (Charlesworth & Charlesworth, 1987): [delta] = 1 - ([w.
95% at a distance of 15 cm, while Martin (1990) in Kansas found that 12 winter wheat varieties outcrossed
Since pollinators usually spend [less than]30 s on an inflorescence, we estimate that natural populations of the study species are highly outcrossed
0%, fluctuating on a yearly basis) are male sterile and fully outcrossed
(del Castillo 1994).
This distantly outcrossed
treatment allowed us to examine the possibility of outbreeding depression by transferring pollen between populations too distant for manual pollen transfer in the wild.