Flowering phenology and mimicry of the rattan Calamus castaneus (Arecaceae) in southern Thailand

Botany ◽  
2012 ◽  
Vol 90 (9) ◽  
pp. 856-865 ◽  
Author(s):  
Aroonrat Meekijjaroenroj Kidyoo ◽  
Doyle McKey
Keyword(s):  
Staminate Flower ◽  
Pistillate Flower ◽  
Flowering Phenology ◽  
Floral Biology ◽  
Olfactory Cues ◽  
Floral Display ◽  
Pollination Success ◽  
Male Flowers ◽  
Intersexual Difference ◽  
And Function

In the insect-pollinated dioecious rattan Calamus castaneus Griff., nectar and pollen rewards, together with visual and olfactory cues, attract insects to male flowers. Pistillate flowers are apparently rewardless. Here, we aimed to clarify the mechanisms assuring visitation and pollination of female flowers. We studied features of flowering phenology and floral biology that affect pollination success of plants of both sexes. The results show that C. castaneus features a striking system of mimicry, quite different from those studied previously in other dioecious plants. The population of C. castaneus was not significantly male biased and no intersexual difference in number of inflorescences per plant was detected. However, male plants began their blossoming earlier and flowered longer than female plants. There was thus an excess of male floral display. This excess should increase the frequency of insect-mediated transport of pollen from male to female plants. Furthermore, on female plants each pistillate flower is accompanied by a sterile staminate flower that appears to contribute to insect attraction. Quite similar in morphology and function to fertile staminate flowers, they produce similar visual and olfactory cues, but less rewards (nectar but no pollen). C. castaneus thus ensures pollination success by intersexual phenological differences and by floral mimicry.

Floral biology of dry rainforest in north Queensland and a comparison with adjacent savanna woodland

2001 ◽  
Vol 49 (2) ◽  
pp. 137 ◽  
Author(s):  
Dinah J. Hansman
Keyword(s):  
Breeding System ◽  
Flowering Phenology ◽  
Floral Biology ◽  
Pollination Syndrome ◽  
Wind Pollination ◽  
Floral Display ◽  
Wet Season ◽  
Savanna Woodland ◽  
Canopy Trees ◽  
Flower Diameter

In north Queensland, Australia, dry rainforest (deciduous and semi-evergreen vine thicket) occurs as patches within a matrix of savanna woodland. With floral morphology and pollen–ovule ratios as indicators of pollination syndrome and breeding system, the floral biology of dry rainforest was compared with that of adjacent savanna woodland and with rainforest elsewhere. Contingency tables and analysis of variance were used to examine and compare breeding system, flower diameter, floral display and putative pollination syndrome for 156 dry rainforest and 33 savanna woodland taxa. Most (91 of 97) dry rainforest species had pollen–ovule ratios indicating obligate outbreeding. Similar levels of dioecy (21%) and patterns of flowering phenology were observed to those reported for rainforests elsewhere. For dry rainforest canopy trees, flower diameter and morphology indicated pollination by small, generalist insects. Canopy trees tended to flower in the wet season and have low ovule numbers. Taxa assigned to the wind-pollination syndrome had the highest pollen–ovule ratios, suggesting less efficient pollen transfer. Sclerophyll savanna taxa (and some emergent dry rainforest trees) tended to flower in the dry season, have large flowers, high ovule numbers and a high level of floral display.

scholarly journals The effect of growth regulators on sex expression in melon (Cucumis melo L.)

2013 ◽  
Vol 13 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Zdenka Girek ◽  
Slaven Prodanovic ◽  
Jasmina Zdravkovic ◽  
Tomislav Zivanovic ◽  
Milan Ugrinovic ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Growth Regulators ◽  
Cucumis Melo ◽  
Staminate Flower ◽  
Sex Expression ◽  
Male Flowers ◽  
Cucumis Melo L ◽  
Perfect Flower

Seven traits related to flowering and sex expression in melon were studied and their reaction to application of two growth regulators (ethrel and gibberellic acid) was observed. Four monoecious genotypes (Sesame, ED-3, ED-4, Pobeditel) and four andromonoecious genotypes (Chinese muskmelon, Anannas, Fiata, A2-3lb) had been used for experiments. According to the results, ethrel had higher effects on the investigated traits than gibberellic acid. Ethrel increased the number of perfect flowers per plant for 7.18 (31.42%), reduced the number of male flowers per plant for 21.47 (17.98%), affected earlier appearance of the first pistillate/perfect flower for 3.68 days, and delayed the appearance of the first staminate flower for 16.07 days. Changes in the last two traits caused an extension of the period from the emergence of the first pistillate/perfect to the first staminate flower from 0.1 to 21.57 days, which represents the strongest effect of ethrel. Gibberellic acid had generally opposite effects on the studied traits.

scholarly journals Floral Biology and Seed Production in Cultivated North American Ginseng (Panax quinquefolius)

2000 ◽  
Vol 125 (5) ◽  
pp. 567-575 ◽  
Author(s):  
Cayetana Schluter ◽  
Zamir K. Punja
Keyword(s):  
Seed Production ◽  
North American ◽  
Age Groups ◽  
Morphological Characteristics ◽  
Floral Biology ◽  
American Ginseng ◽  
Panax Quinquefolius ◽  
Flowering Period ◽  
Pollination Success ◽  
Pollen Release

Morphological characteristics of flowers, duration of flowering, degree of self-pollination, and extent of berry and seed production in North American ginseng (Panax quinquefolius L.) were studied under controlled environmental conditions as well as under field conditions. A comparison was also made between plants of 3 and 4 years of age at two field locations. The duration of flowering was ≈4 weeks and was similar in plants of both age groups grown in the two environments; however, 4-year-old plants produced an average of 40% more flowers (≈100 per plant in total) compared to 3-year-old plants. Flowers were comprised of five greenish-colored petals, five stamens, and an inferior ovary consisting of predominantly two fused carpels and stigmatic lobes. Anthers dehisced in staggered succession within individual flowers, and flowering began with the outermost edge of the umbel and proceeded inwards. At any given time during the 4-week flowering period, ≈10% of the flowers in an umbel had recently opened and were producing pollen. Stigma receptivity was associated with separation of the stigmatic lobes; this occurred at some time after pollen release. Growth of pollen tubes through the style in naturally pollinated flowers was most evident when the stigmatic lobes had separated. The proportion of flowers that developed into mature berries (pollination success rate) was in the range of 41% to 68% for both 3-year-old and 4-year-old plants. However, when the inflorescence was bagged during the flowering period, berry formation was increased by 13% to 21% in 4-year-old plants, depending on location. A majority of the berries (92% to 99%) contained one or two seeds in an almost equal frequency, with the remaining berries containing three seeds. In 4-year-old plants, the frequency of two-seeded berries was increased by ≈13% by bagging the inflorescence. These observations indicate that P. quinquefolius is highly self-fertile and that several physiological and environmental factors can affect seed production.

From landing lights to mimicry: the molecular regulation of flower colouration and mechanisms for pigmentation patterning

2012 ◽  
Vol 39 (8) ◽  
pp. 619 ◽  
Author(s):  
Kevin M. Davies ◽  
Nick W. Albert ◽  
Kathy E. Schwinn
Keyword(s):  
Anthocyanin Biosynthesis ◽  
Flower Colour ◽  
Signal Pathways ◽  
Plant Signaling ◽  
Pollination Success ◽  
Repeat Proteins ◽  
Regulatory Complex ◽  
Colour Patterns ◽  
And Function ◽  
Plant Pollinator

Flower colour is a key component for plant signaling to pollinators and a staggering variety of colour variations are found in nature. Patterning of flower colour, such as pigment spots or stripes, is common and is important in promoting pollination success. Developmentally programmed pigmentation patterns are of interest with respect to the evolution of specialised plant–pollinator associations and as models for dissecting regulatory signaling in plants. This article reviews the occurrence and function of flower colour patterns, as well as the molecular genetics of anthocyanin pigmentation regulation. The transcription factors controlling anthocyanin biosynthesis have been characterised for many species and an ‘MBW’ regulatory complex of R2R3MYB, bHLH and WD-Repeat proteins is of central importance. In particular, R2R3MYBs are key determinants of pigmentation intensity and patterning in plants. Progress is now being made on how environmental or developmental signal pathways may in turn control the production of the MBW components. Furthermore, additional regulatory proteins that interact with the MBW activation complex are being identified, including a range of proteins that repress complex formation or action, either directly or indirectly. This review discusses some of the recent data on the regulatory factors and presents models of how patterns may be determined.

Flowering Phenology, Floral Display and Reproductive Success in the GenusSirindhornia(Orchidaceae): A Comparative Study of Three Pollinator-Rewarding Species

2010 ◽  
Vol 47 (6) ◽  
pp. 439-448 ◽  
Author(s):  
Kanok-orn Srimuang ◽  
Santi Watthana ◽  
Henrik Æ. Pedersen ◽  
Niramol Rangsayatorn ◽  
Prapassorn D. Eungwanichayapant
Keyword(s):  
Reproductive Success ◽  
Comparative Study ◽  
Flowering Phenology ◽  
Floral Display

The pollination ecology of durian (Durio zibethinus, Bombacaceae) in southern Thailand

2009 ◽  
Vol 25 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Sara Bumrungsri ◽  
Ekapong Sripaoraya ◽  
Thanongsak Chongsiri ◽  
Kitichate Sridith ◽  
Paul A. Racey
Keyword(s):  
Floral Biology ◽  
Pollination Ecology ◽  
Fruit Bats ◽  
Pollination Experiments ◽  
Pollination Success ◽  
Durio Zibethinus ◽  
Fruit Bat ◽  
Southern Thailand ◽  
Fruit Orchards ◽  
Frequent Visitor

Abstract:The floral biology and pollination ecology of durian, Durio zibethinus, were determined in eight semi-wild trees in mixed-fruit orchards in southern Thailand during April-May 2003 and 2005. Flowers open fully at 16h00–16h30 and most androecia drop around 01h00. Anthers dehisce at 19h30–20h00 when the stigmata are already receptive. In a series of pollination experiments, fruit was set in all treatments within 10 d. The greatest pollination success occurred after hand-crossed (76.6%), open (54.4%) and emasculation pollination (53.3%). Consistently, hand-crossed (12.2%), emasculation (8.7%) and open pollination (5.1%) yielded a substantial fruit set 2 mo after the pollination experiments. Very low pollination success in facilitated autogamy suggests that most durian trees are highly self incompatible. No mature fruit was found after insect pollination and automatic autogamy. Fruit bats, especially Eonycteris spelaea, are the major pollinators of this durian although the giant honey bee (Apis dorsata) was the most frequent visitor to the flowers. Bats visited durian flowers at the rate of 26.1 (SD = 20.7) visits per inflorescence per night. Since this semi-wild durian depends on fruit bats as its pollinator, protecting fruit bat populations and their roosts is vital for the production of the durian fruit crop.

Pollination ecology of the dioecious tree Commiphora guillauminii in Madagascar

2004 ◽  
Vol 20 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Nina Farwig ◽  
Emile F. Randrianirina ◽  
Friederike A. Voigt ◽  
Manfred Kraemer ◽  
Katrin Böhning-Gaese
Keyword(s):  
Plant Species ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Bird Species ◽  
Pollination Ecology ◽  
Floral Display ◽  
Flower Visitation ◽  
Visitation Rates ◽  
Male Flowers ◽  
Female Flowers

In dioecious plant species differences in morphology and resources between female and male flowers can have consequences for flower visitation rates. Female flowers sometimes lack pollen and can be less attractive to pollinators than male flowers. We studied the pollination ecology of the dioecious tree Commiphora guillauminii in a dry deciduous forest in western Madagascar. We recorded floral display, visiting insect species and visitation rates for female and male trees. The results showed that female trees produce significantly larger but fewer flowers per inflorescence than male ones. Number of flowers per tree did not differ between the sexes. During 270 observation-hours we observed 17 insect and two bird species visiting the flowers. Mean visitation rates of male flowers were 6.1 times higher than those of female flowers (1.07 vs. 0.18 visitors per flower h−1). Visitation rates to female and male trees showed similar daily and seasonal patterns. Fruit set (2.9%) was low, which could have been caused by pollinator or pollen limitation. This study suggests that dioecy may pose a risk for fruit set and, potentially, reproductive success for plant species with depauperate pollinator faunas on islands such as Madagascar.

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