In determining the auto-incompatibility among flowers of the same plant (geitonogamy
), after seven days of manual pollination, when removing flowers from bags, it was verified the absence of fruit in 100% of pollinated flowers.
In the natural population, the difference observed between fruit set resulting from spontaneous self-pollination and the one resulting from open pollination (Table 1) reinforced the importance of geitonogamy
in that species.
Those insects frequently came into contact with the reproductive structures of the flowers while collecting pollen, thus favoring pollination, and their habit of visiting two to three inflorescences on the same plant would facilitate pollination by geitonogamy
Open pollination through cross pollinated flowers produced longer pods (13.3cm and 14.5 cm, respectively), more pod weight (9.09 gm and 9.83 gm respectively), more seeds per pod (10.9 seeds and 10.1 seeds per pod respectively) and higher seed germination percentage (82% and 94% respectively) than did self pollinated and geitonogamy
The outcross (X) treatment produced significantly more fruits per treatment flower (0.47 [+ or -] 0.04) than the autogamy (A; 0.04 [+ or -] 0.01), geitonogamy
(G; 0.02 [+ or -] 0.01), and open control (O; 0.24 [+ or -] 0.03) treatments.
mellifera evinced that this bee visits several flowers of a same individual favouring geitonogamy
(Garcia-Franco 1990) a conclusion based on the fact that no fruits were produced in non-assisted selfing while there was only 7.89% of fruit set in geitonogamy
However, breeding systems vary within the Papilionoideae from obligate selfers (geitonogamy
and autogamy) to obligate outcrossers (cross pollination between flowers from different plants), with some Papilionoideae taxa, including some Astragalus species, capable of both (Karron 1987a; Arroyo 1981; Juan et al.
Treatment 2) The flower was emasculated as above, but not bagged, so that seeds that matured would be the result of either geitonogamy
(in which an ovule is fertilized by pollen from a different flower on the same plant) or xenogamy (in which the pollen is transferred from a different individual), but not intrafloral self-pollination.
In contrast, between-flower self-pollination (geitonogamy
) provides no reproductive assurance and can cause severe seed and pollen discounting.
Pollen losses due to geitonogamy
(i.e., pollen discounting) might have been artificially high for the same reason: the residence times of Andrena pollinators on Zigadenus inflorescences are known to increase with inflorescence size (Emms 1993c).