| Abstract: | Field observation on pollination in three populations of Paeonia suffruticosa subsp. spontanea in southern Shanxi Province showed that five species of bees in two families
and four species of beetles were engaged in pollination. Examination on bodies of these in sects under SEM, and seed set produced by controlled insect-pollination indicated that the bees, especially the species in the genus Andrena were main pollinators and the beetles except those of small size were only fluctuating vectors. Flowers of this taxon are scented and nonectariferous. Flowers attracted bees and beetles mainly by pollen. A study on seed-set in the three populations revealed considerable variation within and among populations. The plants were no apomict and autogamy, but geitonogamy sometimes could produce mature seeds (x＝ 2.86 seeds per carpel). In the population with less flowers (less than 40 flowers), natural seed-set (x＝3.88) was close to the seed-set produced by hand cross-pollination (x = 3.21), but in the population with more flowers(near 100 flowers) natural seed-set (x＝ 2.48) was lower than that by hand cross-pollination (x = 3.21). The seed-set was low for
both natural and artificial cross-pollination with only about one forth of ovules developing into seeds. |
