Biology Reference
In-Depth Information
across-family comparison, however, to investigate whether this trend also holds
true within annuals exclusively.
Data on the timing of life history stages (i.e. age at first flower, bud develop-
ment time, and flower longevity) were also obtained from a greenhouse study of
25 annual species involving 5 families. The time-limitation hypothesis predicts
that selfers should produce mature flowers more quickly and should have shorter
flowering times.
Results
Data Base Analyses
Based on phylogenetically-independent contrasts, selfing annuals had signifi-
cantly shorter plant heights (Wilcoxon test for matched pairs, n = 12, T = 15.5,
one-tailed P = 0.032, Figure 2a), significantly smaller flowers (Wilcoxon test for
matched pairs, n = 14, T = 13, one-tailed P = 0.0054, Figure 2b), and significantly
smaller seeds (Wilcoxon test for matched pairs, n = 13, T = 13, one-tailed P <
0.01, Figure 2c).
Figure 2.
(a) Plant height contrasts for 13 selfing and outcrossing pairs (some points overlap), where each pair
consists of the median value of the selfing and outcrossing species within one family. (b) Flower size contrasts for
14 selfing and outcrossing pairs. (c) Seed size constrasts between 14 selfing and outcrossing pairs.
