Bog ericad flowers: self-compatibility and relative attractiveness to bees

1977 ◽  
Vol 55 (17) ◽  
pp. 2279-2287 ◽  
Author(s):  
R. J. Reader
Keyword(s):  
Seed Set ◽  
Floral Morphology ◽  
Flower Visitors ◽  
Hand Pollination ◽  
Insect Visitation ◽  
Relative Attractiveness ◽  
Self Compatibility ◽  
Insect Visitors

The seed set of eight bog plants in the Ericaceae family was reduced by excluding insect flower visitors even though hand-pollination tests showed that all eight species were self-compatible. Floral morphology evidently minimizes the possibility that pollen will be transferred from anther to stigma in the absence of insect visitation. Bees were the most important flower visitors, collecting nectar and (or) pollen. The attractiveness (nectar and (or) pollen extractable per minute) of the ericad flowers varied considerably. This variability would promote forager specialization and flowering-timing diversification if the ratio of insect visitors to flowers was low.

A comparison of flower-visiting insects to rare Symphyotrichum sericeum and common Solidago nemoralis (Asteraceae)

Botany ◽  
2010 ◽  
Vol 88 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Diana Bizecki Robson
Keyword(s):  
Seed Set ◽  
Visitation Rate ◽  
Hand Pollination ◽  
Insect Visitation ◽  
The Common ◽  
Insect Activity ◽  
Flower Visiting ◽  
Common Plant ◽  
Insect Visitors ◽  
Over Time

Flower-visiting insect activity to the rare Symphyotrichum sericeum (Vent.) G.L. Nesom and the common Solidago nemoralis Ait. var. longipetiolata (Mack. & Bush) Pal. & Steyerm. was examined to detect compositional and temporal similarities. A hand pollination experiment was conducted to determine whether pollen was limiting seed set. Of the 31 insect taxa that visited these plants, Bombus bifarius Cresson was the most common visitor to both species. More insect visitors of the Halictidae and Bombyliidae were received by S. sericeum than S. nemoralis, which received more visitors of the Syrphidae and Tachinidae. The insect visitation rate was not significantly different between the two plant species. Solidago nemoralis was visited by fewer insect taxa per day than S. sericeum, but the constancy of its visitors was higher. The insect visitor composition changed over time, with B. bifarius ignoring S. sericeum plants initially, then visiting them more frequently as the number of receptive S. nemoralis capitula declined. Hand pollination increased seed set in the earliest flowering capitula of S. sericeum, but not for those flowering during the peak. This research shows that the quantity of insect visits to the rare plant is comparable with that of the common plant but that pollination quality may be lower, particularly for early blooming capitula.

scholarly journals Polygamous breeding system identified in the distylous genus Psychotria: P. manillensis in the Ryukyu archipelago, Japan

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12318
Author(s):  
Kenta Watanabe ◽  
Akira Shimizu ◽  
Takashi Sugawara
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Sexual Expression ◽  
Ryukyu Islands ◽  
Ryukyu Archipelago ◽  
Open Pollination ◽  
Flower Visitors ◽  
Hand Pollination ◽  
Self Compatibility ◽  
Preliminary Study

Distyly is a genetic polymorphism composed of long-and short-styled flowers in a population. The evolutionary breakdown of distyly has been reported in many taxa, and mainly involves a shift toward monomorphism or dioecism. However, a shift toward monoecism has not been reported in distylous species. Psychotria (Rubiaceae), one of the world largest genera, consists of distylous species and their derivatives. In our preliminary study, however, we identified some monoecious individuals in a population of Psychotria manillensis. To understand the breeding system and reproductive biology of P. manillensis, we investigated floral traits, open fruit set, and flower visitors, and performed hand pollination and bagging experiments in five populations of Okinawa and Iriomote islands, Ryukyu Islands, Japan. The populations of P. manillensis were composed mainly of monoecious individuals (54%), followed by female (30%), male (14%), and hermaphroditic (2%) individuals at the time of flower collection. Of the collected flowers, 93% were functionally unisexual (male or female), whereas only 6.5% were perfect (hermaphroditic). However, some individuals changed sex mainly towards increasing femaleness during the flowering period. Moreover, 35% of the studied plants changed their sexual expression over the years. P. manillensis showed self-compatibility and no agamospermy. The fruit set under open pollination varied among populations and years (1.8–21.9%), but it was significantly higher than that of auto-selfing (0.68–1.56%). Wasps and flies were the main flower visitors and probably the main pollinators of the species. In conclusion, P. manillensis was revealed to be polygamous, involving monoecious, female, male, and hermaphroditic individuals. This is the first report of the polygamous breeding system not only in the genus Psychotria, but also in all heterostylous taxa.

scholarly journals Polygamous breeding system identified in the distylous genus Psychotria: P. manillensis in the Ryukyu archipelago, Japan

2020 ◽  
Author(s):  
Kenta Watanabe ◽  
Akira Shimizu ◽  
Takashi Sugawara
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Sexual Expression ◽  
Ryukyu Islands ◽  
Ryukyu Archipelago ◽  
Open Pollination ◽  
Flower Visitors ◽  
Hand Pollination ◽  
Self Compatibility ◽  
Preliminary Study

AbstractThe evolutionary breakdown of distyly has been reported in many taxa, and mainly involves a shift toward monomorphism or dioecism. However, a shift toward monoecism has not been reported in distylous species. Psychotria (Rubiaceae), one of the world largest genera, consists of distylous species and their derivatives. In our preliminary study, however, we identified some monoecious individuals in a population of Psychotria manillensis. To understand the breeding system and reproductive biology of P. manillensis, we investigated floral traits, open fruit set, and flower visitors, and performed hand pollination and bagging experiments in five populations of Okinawa and Iriomote islands, Ryukyu Islands, Japan. The populations of P. manillensis were composed mainly of monoecious individuals (44%), followed by female (38%), male (14%), and hermaphroditic (3%) individuals at the time of flower collection. Of the collected flowers, 94% were functionally unisexual (male or female), whereas only 6% were perfect (hermaphrodic). However, some individuals changed sex mainly towards increasing femaleness during the flowering period. Moreover, 35% of the studied plants changed their sexual expression over the years. P. manillensis showed self-compatibility and no agamospermy. The fruit set under open pollination varied among populations and years (1.8–21.9%), but it was significantly higher than that of auto-selfing (0.68–1.56%). Wasps and flies were the main flower visitors and probably the main pollinators of the species. In conclusion, P. manillensis was revealed to be polygamous, composed of monoecious, female, male, and hermaphroditic individuals. This is the first report of the polygamous breeding system not only in the genus Psychotria, but also in all heterostylous taxa.

Hand-Pollination ofCardamine californicaImproves Seed Set

2006 ◽  
Vol 7 (3) ◽  
pp. 248-252 ◽  
Author(s):  
Kazuki Ariyoshi ◽  
Emily Magnaghi ◽  
Mark Frey
Keyword(s):  
Seed Set ◽  
Hand Pollination

CORRELATED RESPONSE IN BROWN SARSON

1970 ◽  
Vol 12 (4) ◽  
pp. 905-913 ◽  
Author(s):  
T. Swamy Rao
Keyword(s):  
Gamma Irradiation ◽  
Seed Set ◽  
Previous History ◽  
The Self ◽  
Correlated Response ◽  
History Of ◽  
Self Compatibility ◽  
Selection For ◽  
Direction Opposite ◽  
Brown Sarson

The correlated response with changes in self-compatibility in three varieties of brown sarson subjected to gamma irradiation was examined. Selection for improved seed set in the irradiated populations showed that substantial correlated response can result for a constellation of other characters in which the self-compatible and self-incompatible forms differ. The correlated response was in a direction opposite to that of the previous history of selection.

INFLUENCE OF MOISTURE STRESS, RELATIVE HUMIDITY AND OXYGEN DIFFUSION RATE ON SEED SET AND YIELD OF WHEAT

1969 ◽  
Vol 49 (1) ◽  
pp. 29-37 ◽  
Author(s):  
C. A. Campbell ◽  
D. S. McBean ◽  
D. G. Green
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Oxygen Diffusion ◽  
Seed Set ◽  
Diffusion Rate ◽  
Moisture Stress ◽  
Morphological Examination ◽  
Hand Pollination ◽  
Growth Chamber Studies ◽  
Oxygen Diffusion Rate

The influence of oxygen diffusion rate (ODR) and relative humidity (RH) on seed set and yield of wheat was investigated in two growth chamber studies. In one study, plants grown at 80% RH were compared with those grown at 60%. In the other, plants grown in pots without supplemental aeration were compared with plants grown in aerated pots.Wheat grown at low soil moisture stress (between 25 and 16%) produced significantly poorer seed set and grain yield than those grown at higher stress (between 25 and 10%). Seed set was less severely reduced in Manitou than in Chinook. Plants grown at low moisture stress and 60% RH gave better seed set than those grown at 80%. However, even at 60% RH, seed set was less than 65%.The oxygen diffusion rates in unaerated pots were 28 × 10−8, 100 × 10−8 and 200 × 10−8 g cm−2min−1 at 25%, 16% and 10% soil moisture (by weight). In aerated pots, ODR at 25% and 16% soil moisture were 82 × 10−8 and 180 × 10−8 g cm−2min−1, respectively.Seed set and grain yields of Chinook wheat grown at low moisture stress were increased from 54 to 82% and from 11.5 to 26.7 g/pot by improving the soil aeration.The anthers, especially the pollen, were the main reproductive components damaged by poor aeration. This was demonstrated by morphological examination and by hand-pollination experiments. Poor seed set was confined primarily to the top two-thirds of the head.

scholarly journals Role of insect visits on cucumber (Cucumis sativus L.) yield

2018 ◽  
Vol 4 (2) ◽  
pp. 81-88
Author(s):  
MS Hossain ◽  
F Yeasmin ◽  
MM Rahman ◽  
S Akhtar ◽  
MA Hasnat
Keyword(s):  
Cucumis Sativus ◽  
Honey Bee ◽  
Foraging Behaviour ◽  
Apis Cerana ◽  
Bee Pollination ◽  
Cucumis Sativus L ◽  
M 10 ◽  
Hand Pollination ◽  
Insect Visitors

The foraging activities of insect visitors on cucumber (Cucumis sativus L.) were studied. The insect visitors in decreasing order of abundance were: Formica sp.>Apis mellifera>Apis cerana>syrphids≥Apis dorstata. The activity of insects was peaked at 08.00-09.00 am. The foraging behaviour of A. mellifera was also studied. The bees spent significantly more time per flower during morning hours (sec/flower) and foraged significantly fewer flowers (7.9 flowers/min) compared to evening hours. There were significantly more nectar foragers (6.03/m²/10 min) than pollen foragers (5.16/m²/10 min). Most pollen foragers were observed during morning hours (6.59/m²/10 min) whereas nectar foragers were most active during noon hours (6.63/m²/10 min). Highest fruit set was observed in hand pollination (70.68%). Percentage of misshapen fruits was maximum in without honey bee pollination (24.35%). Without honey bee pollination resulted in significantly lowest percentage of healthy fruits (75.25%). Hand pollination ranked highest among the three forms of pollination in respective of fruits (985.13 g), number of seeds per fruit (425.22), fruit diameter (27.1 cm), fruit length (26.7 cm) and weight of 1000-seeds (28.64 g). J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(2): 81-88

Reproductive ecology of Dryas integrifolia in the high Arctic semi-desert

1996 ◽  
Vol 74 (9) ◽  
pp. 1451-1460 ◽  
Author(s):  
P. G. Krannitz
Keyword(s):  
Seed Dispersal ◽  
Seed Set ◽  
High Arctic ◽  
The Arctic ◽  
Bet Hedging ◽  
Crop Failure ◽  
Flower Stalk ◽  
Insect Visitation ◽  
Solar Noon ◽  
Seed Data

Flowering and fruiting of Dryas integrifolia were studied at Igloolik and Pangnirtung to analyse the importance of variation in heliotropy and flower size to seed set and weight. In addition, peduncle elongation and seed plume length were also studied to analyse variation in seed dispersal characters. At both Igloolik and Pangnirtung, most Dryas flowers were not heliotropic throughout the course of the day, but in general, pointed towards the solar noon sun. Benefits to orienting toward the sun were warmer gynoecial temperatures, heavier seeds, and more insect visitation (though not percent seed set). Flowers varied in size from 1.2 to 2.7 cm in diameter and differed in size between plants. Even though larger flowers did not point towards the solar noon sun more than smaller flowers, they had heavier and proportionally more seeds. Variation in peduncle elongation suggests the potential for conservative dispersion when a flower has produced only a few propagules: flowers with fewer or no seeds had shorter stalks. Similarly, with good seed production, a bet hedging strategy is apparent: seeds located at the centre of the receptacle had much longer plumes than those at the perimeter of the seed head. All seed data were from Pangnirtung; the cold summer in 1986 at Igloolik resulted in a complete seed crop failure. Despite the adversity of the arctic climate, there are moderate summers during the lifetime of perennial plants such as D. integrifolia in which adaptations like those described in this study benefit the production of sexual offspring. Keywords: heliotropism, flower stalk elongation, basking insects, seed dispersal, insolation, bet hedging.

scholarly journals The Flowering, Pollen Production, and Insect Visitors in the Ornamental Shrub Potentilla Fruticosa L. (Rosaceae)

2013 ◽  
Vol 57 (1) ◽  
pp. 95-106 ◽  
Author(s):  
Bożena Denisow ◽  
Sebastian Antoń ◽  
Grażyna Szymczak
Keyword(s):  
Urban Areas ◽  
Ornamental Plants ◽  
Pollen Production ◽  
Flowering Pattern ◽  
Potentilla Fruticosa ◽  
Full Flowering ◽  
Insect Visitation ◽  
Pollen Productivity ◽  
Ornamental Shrub ◽  
Insect Visitors

Summary Urban areas have a specific ecological environment and may help to sustain local pollinator populations by the cultivation of different ornamental plants with entomophilous flowers. This yearlong study examined the flowering pattern, abundance of flowering, pollen production as well as insect visitation of two cultivars of the ornamental shrub Potentilla fruticosa L. (‘Maanleys’ and ‘Blink’), grown in Lublin; a city in south-eastern Poland. P. fruticosa ‘Maanleys’ bloomed from the middle of May to the first decade of September and P. fruticosa ‘Blink’ from June until October. The pattern of diurnal flowering was similar for both cultivars and showed plasticity in the season. Flowers opened most intensively in the morning hours, and 80 - 90% of the daily installment of newly opened flowers expanded by 8.00 h GMT +2h. A delay in the peak of diurnal flowering was noted between the spring/summer and summer/autumn periods. The most intense blooming fell in the 2nd month of flowering. The mass of pollen produced per flower depended on both the number of anthers and the efficiency of archesporial tissues. The pollen output varied from 1.4 to 7.2 mg per 10 flowers (‘Maanleys’) and from 2.6 to 4.5 mg per 10 flowers (‘Blink’). The mass of pollen produced per individual shrub was substantially related to the abundance of blooming. The average estimated pollen productivity in the full flowering phase was low; 1 g (‘Maanleys’) and 1.5 g (‘Blink’) per 10 m2 of shrub crown. The flowers of Potentilla fruticosa attracted numerous insects, mainly solitary bees (33 - 43%), dipterans (31 - 42%), lepidopterans (4 - 14%), bumblebees (3 - 15%), and honey bees (3 - 4%). The Potentilla fruticosa ‘Maanleys’ and ‘Blink’ are propagated for specific ornamental arrangements and due to a long flowering period may be used in small urban courtyards for both decorative value and as a pollen delivering plants.

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