The Pollination Biology of Eleutherococcus senticosus (Araliaceae)

LIU Lin-De, WANG Zhong-Li, TIAN Guo-Wei, SHEN Jia-Heng

Received:1900-01-01 Revised:1900-01-01 Online:1998-01-10 Published:1998-01-10
Contact: LIU Lin-De

Abstract:

This paper reports floral rewards, flower visitors, foraging behavior and visitation

rate of flower visitors on inflorescences, and the pollination effect of Eleutherococcus sentico-

sus (Rupr. et Maxim. ) Maxim. The main results are as follows: (1) A male flower can pro-

vide 58 000～81 000 pollen grains and 5.5～8.0 μ1/d × 2～3 d of nectar, while a female

flower can provide 4.0～8.0μl/d × 2～3 d of nectar but no pollen grains. A hermaphrodite

flower can provide 19 000～54 000 pollen grains and 7.0～10.0μl/d × 2～6 d of nectar;

when it is at male phase, it can provide pollen as well as nectar, but when it is at female

phase, it can only provide nectar. (2) The male and hermaphrodite flowers, if they provide

pollen grains, are pollen donors. The female and hermaphrodite flowers with white and open

stigmas are pollen recipients. The rewarding phase of pollen donor lasts 1～3 days after

anthesis and that of pollen recipient is between 5～7 or 7～9 days after anthesis. This may con-

firm that E. senticosus is protandrous. In addition, the nectar-rewarding period of pollen

donors is from 8:30 to 16:00, and its peak is at 9:00～15:00; while that of pollen recipi-

ents is from 10:30 to 16:30, with its peak from 11:00 to 16:00. It is suggested that the

difference between the two nectar-rewarding peaks be the key factor which affects the polli-

nators' visiting direction from pollen donors to pollen recipients. (3) More than 50 species of

visiting insects were observed. Visitors most frequently seen are arranged in Hymenoptera,

Lepidoptera, Coleoptera, Diptera and Hemiptera-Heteroptera in order. Their visitation rate

and visitation peak are influenced by different plants of different sexes, in different habitats

and under different weather conditions. Generally, the peak of visitation to pollen donors is

earlier than that to pollen recipients; the rate of visitation to male patch is higher than that to

female patch. In the case of hermaphrodite patch, the visitation rate is higher when receiving

pollen than when supplying. In addition, the brighter the sky is or the larger the E. sentico-

sus patch is, the higher the visitation rate and peak are; the earlier the plant patch is shone

in a day, the earlier the visiting peak comes. (4) From the pollination effect, we may con-

clude that the seed set of E. senticosus totally depends on pollinators'visitation. And bees

such as Bumbus, Halictus, Megachile, Vespa, Apis are the most efficient pollinators,

while other insects, including Pieridae, Syrphidae, Tachinidae, Melolonthidae and so on,

are also helpful for the pollination success.

Key words: Eleutherococcus senticosus, Pollination biology

LIU Lin-De, WANG Zhong-Li, TIAN Guo-Wei, SHEN Jia-Heng. The Pollination Biology of Eleutherococcus senticosus (Araliaceae)[J]. .

[1]	LIU Lin-De, WANG Zhong-Li, TIAN Guo-Wei, SHEN Jia-Heng. Megasporogenesis, Microsporogenesis and Development of Gametophytes in Eleutherococcus senticosus (Araliaceae) [J]. , 1998, 36(4): 289-297.
[2]	LIU Lin-De, WANG Zhong-Li, TIAN Guo-Wei, SHEN Jia-Heng. The Development of Embryo and Endosperm in Eleutherococcus senticosus (Araliaceae) [J]. , 1998, 36(4): 298-304.
[3]	LIU Lin-De, WANG Zhong-Li, TIAN Guo-Wei, SHEN Jia-Heng. The Development of Gynoecium after Anthesis and Fertilization in Eleutherococcus senticosus (Araliaceae) [J]. , 1998, 36(2): 111-118.
[4]	Liu Lin-de, Wang Zhong-li, Tian Guo-wei, Shen Jia-heng. Studies on Sexual Reproduction and Vegetative Propagation of Eleutherococcus senticosus (Araliaceae) [J]. , 1997, 35(1): 7-13.
[5]	Liu Lin-de, Wang Zhong-li, Tian Guo-wei, Shen Jia-heng. Observation on Floral Morphology and Heteranthery of Eleutherococcus senticosus (Araliaceae) [J]. , 1997, 35(1): 1-6.

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