Adaptive Significance of Ipomopsis Aggregata Nectar Production: Pollination Success of Single Flowers

Ecology ◽  
1992 ◽  
Vol 73 (2) ◽  
pp. 633-638 ◽  
Author(s):  
Randall J. Mitchell ◽  
Nickolas M. Waser
Keyword(s):  
Adaptive Significance ◽  
Ipomopsis Aggregata ◽  
Nectar Production ◽  
Pollination Success

scholarly journals Horizontal orientation facilitates pollinator attraction and rain avoidance in radially symmetrical flowers

2021 ◽  
Author(s):  
Taichi Nakata ◽  
Ishii Rin ◽  
Yuki A Yaida ◽  
Atushi Ushimaru
Keyword(s):  
Field Experiments ◽  
Pollen Grains ◽  
Adaptive Significance ◽  
Pollinator Limitation ◽  
Pollinator Attraction ◽  
Pollination Success ◽  
Horizontal Orientation ◽  
Flowering Season ◽  
Germination Experiment ◽  
Female Success

AbstractPremiseFloral angle, such as upward, horizontal, and downward orientation are known to evolve under both biotic and abiotic agents to enhance pollination success in zoophilious plants. Adaptive significance of horizontal orientation in radially symmetrical (actinomorphic) flowers under biotic and abiotic selection pressures were largely unknown, although those in bilaterally symmetrical flowers have been well studied.MethodsUsing experimentally angle changed flowers, we examined the effects of flower angle on pollinator behaviors, pollination success and rain avoidance in a population of insect-pollinated Platycodon grandiflorus. We further investigated the frequency and amount of precipitation in the flowering season and pollen damage by water in this species. Main results: Horizontally oriented flowers received more visitations and pollen grains on the stigma in male and/or female phases than downward and/or upward oriented flowers and avoided pollen damage by rainfall compared to upward oriented flowers. The pollen germination experiment showed that approximately 30% of pollen grains burst in distilled water, thus pollen damage by rainfall was potentially serious in P. garndiflorus.ConclusionIn this study, our field experiments revealed that upward flowers cannot avoid damage from rainfall during the flowering period whereas both upward and downward flowers suffered from pollinator limitation in female success. Thus, horizontal flower orientation is suggested to be adaptive in this insect-pollinated actinomorphic species which blooms in the rainy season.

Female-biased nectar production in the protandrous, hermaphroditic shrub Salvia hierosolymitana (Lamiaceae)

2011 ◽  
Vol 59 (1) ◽  
pp. 18 ◽  
Author(s):  
Yehoram Leshem ◽  
Tamar Keasar ◽  
Avi Shmida
Keyword(s):  
Vertical Distribution ◽  
Nectar Production ◽  
Short Supply ◽  
Pollination Success ◽  
Female Phase ◽  
Male Phase ◽  
Sterile Pollen ◽  
Germinated Pollen ◽  
Two Populations ◽  
Nectar Availability

Flowering progresses upward along vertical inflorescences in the protandrous dichogamous shrub Salvia hierosolymitana (Boiss.). Flowers’ gender nectar production rates and their vertical distribution were recorded in two populations (northern and central Israel) over 3 years. Female-phase flowers produced significantly more nectar than male-phase flowers and were more abundant at the inflorescences’ base. Thus, nectar availability gradually decreases along inflorescences. Female-biased nectar production can benefit plants by increasing pollinator visits to female-phase flowers, enhancing pollination success when pollen is scarce. In congruence with this hypothesis, the following observations suggest that pollen in S. hierosolymitana may be in short supply: (1) freshly dehisced anthers contained 40% of sterile pollen; (2) pollen counts on female-phase stigmas were low (mean ± s.e. 11.6 ± 1.56); and (3) counts of germinated pollen tubes at the pistils’ base were even lower (5.02 ± 0.54). The nectar gradient along the inflorescence may also be adaptively beneficial in other aspects. Foraging insects that follow this gradient are expected to move from female-phase flowers near the inflorescences’ base, to male-phase flowers closer to the top. Thus, reducing the risk of geitonogamy and promoting outcrossing while moving from male-phase flowers of one individual to female-phase flowers of another.

Adaptive significance of mass-flowering in Hedychium coccineum (Zingiberaceae)

2013 ◽  
Vol 20 (3) ◽  
pp. 376-385
Author(s):  
Gao Jiangyun ◽  
Sheng Chunling ◽  
Yang Shuxia
Keyword(s):  
Adaptive Significance ◽  
Mass Flowering

Influence of Phenotype, Season, and Time‐of‐day on Nectar Production in Cotton 1

Crop Science ◽  
1981 ◽  
Vol 21 (4) ◽  
pp. 507-511 ◽  
Author(s):  
Gordon D. Waller ◽  
F. D. Wilson ◽  
Joseph H. Martin
Keyword(s):  
Time Of Day ◽  
Nectar Production
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