Nectar secretion pattern, removal effects, and breeding system of Ligaria cuneifolia (Loranthaceae)

1996 ◽  
Vol 74 (12) ◽  
pp. 1996-2001 ◽  
Author(s):  
Guillermo L. Rivera ◽  
Leonardo Galetto ◽  
L. Bernardello
Keyword(s):  
Reproductive Biology ◽  
Breeding System ◽  
Nectar Production ◽  
Female Function ◽  
Flower Nectar ◽  
Flower Age ◽  
Female Phase ◽  
Male Phase ◽  
Pattern Removal ◽  
Flower Phenology

Some aspects of the reproductive biology of Ligaria cuneifolia have been studied, addressing the following questions: (i) Are there temporal differences in the female and male functions? (ii) How do nectar composition, volume, concentration, and amount of sugar vary throughout the flower lifetime? (iii) How does the plant respond to nectar removal? (iv) What is the breeding system of this species? Flowers last 4 days. There is a predominance of the male function in the first days and of the female function in the last days. Chemical composition of nectar varies throughout the flower lifetime; there is a constant decrease in sucrose along with an increase in glucose. Nectar is secreted during nights, and every secretion period is followed by a cessation interval. After the final cessation, a period of active resorption follows. During the mostly male phase of the flower, nectar has more sucrose than hexose, its secretion is discontinuous, and nectar removal reduces the rate of nectar production. During the mostly female phase, nectar has more hexose than sucrose, its secretion ceases, nectar removal does not affect nectar production, and a resorption period is inferred. Tests for spontaneous autogamy and apomixis were negative. Low fruit set is obtained when autogamous, geitonogamous, and xenogamous hand pollinations are performed on flowers less than 2 days old compared with flowers at least 3 days old (0, 15, and 47% versus 19, 37.5, and 89%, respectively). These results indicate the the reproductive system of L. cuneifolia is primarily xenogamous, but reproductive success is related to flower age. Keywords: Loranthaceae, Ligaria, nectar chemistry, breeding system, flower phenology, reproductive biology.

Seed Production, Pollinator Attractants and Breeding System in Relation to Fire Response — Are There Reproductive Syndromes among Co-occurring Proteaceous Shrubs?

1998 ◽  
Vol 46 (4) ◽  
pp. 377 ◽  
Author(s):  
Byron B. Lamont ◽  
Jens M. Olesen ◽  
Peter J. Briffa
Keyword(s):  
Seed Production ◽  
Reproductive Biology ◽  
Breeding System ◽  
Consistent Pattern ◽  
The Other ◽  
Severe Stress ◽  
Fire Response ◽  
Flower Production ◽  
Species Pairs ◽  
Flower Phenology

The reproductive biology of two species pairs was compared, one member of which (Dryandra sessilis (Knight) Domin, Hakea erinacea Meissner) is susceptible to severe stress and disturbance by fire (nonsprouter) and stores few seeds in its crown, while the other (D. lindleyana Meissner, H. cristata R.Br.) is resilient (resprouter) and also stores most of its seeds for some years. It was hypothesised that the nonsprouter would have a high annual seed production associated with a suite of attributes directed towards that end (forming a reproductive syndrome), and that the resprouter would have the reverse properties. Over 30 attributes were assessed, covering putative pollinators, pollinator attractants and rewards, flower phenology, breeding system, and flower, fruit and seed production. Dryandra sessilis produced far more seeds than D. lindleyana, due to prolific flower production and a high fruit : flower ratio (associated with an effective outcrossing breeding system). Hakea erinacea produced significantly more seeds than H. cristata, which was attributable to its smaller fruits and exceptionally high fruit : flower ratio (associated with highly effective selfing). The correlation of seed production and fruit : flower ratio with susceptibility to fire was not supported by any consistent pattern among the other reproductive attributes.

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.

scholarly journals Reproductive biology and breeding system of Saraca asoca (Roxb.) De Wilde: a vulnerable medicinal plant

SpringerPlus ◽  
2016 ◽  
Vol 5 (1) ◽  
Author(s):  
G. R. Smitha ◽  
V. Thondaiman
Keyword(s):  
Medicinal Plant ◽  
Reproductive Biology ◽  
Breeding System ◽  
Saraca Asoca

Pollination of Amorphophallus johnsonii (Araceae) by carrion beetles (Phaeochrous amplus) in a Ghanaian rain forest

1996 ◽  
Vol 12 (3) ◽  
pp. 409-418 ◽  
Author(s):  
Daniel D. N. Beath
Keyword(s):  
Rain Forest ◽  
Rainy Season ◽  
Male Inflorescence ◽  
Large Numbers ◽  
Female Phase ◽  
Male Phase ◽  
Carrion Beetles ◽  
Main Rainy Season

ABSTRACTAmorphophallus johnsonii (N. E. Brown) flowers during April in the main rainy season in Ghana. Anthesis starts at dusk with fluid oozing from the upper spadix accompanied by a strong aminoid odour. Just after dark large numbers of carrion beetles (Phaeochrous amplus) and occasional dung fly species (Hemigymnochaeta unicolor and Paryphodes tigrinus) visit the inflorescences. The beetles become trapped in the lower spathe overnight and remain in the spadix until the following evening. Between 1630 and 1645 h the following day, the anthers produce long threads of sticky pollen. The trapped beetles escape just after dark by crawling up the spadix, past the dehisced anthers and fly away from the spadix tip. Marked beetles were seen to transfer pollen from male phase to female phase inflorescences. Successful fertilisation was only effected if pollen was transferred on the same night from a male inflorescence 30 m or less away. Pollen is psilate and typical of beetle pollinated Araceae. Berries ripen approximately 70 d after fertilization and ripen basisetally in the infructescence.

scholarly journals Male flowers of Aconitum compensate for toxic pollen with increased floral signals and rewards for pollinators

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A.-L. Jacquemart ◽  
C. Buyens ◽  
M.-F. Hérent ◽  
J. Quetin-Leclercq ◽  
G. Lognay ◽  
...  
Keyword(s):  
Larval Food ◽  
Chemical Defences ◽  
Toxic Nectar ◽  
Pollen Transfer Efficiency ◽  
Aconitum Napellus ◽  
Female Phase ◽  
Male Phase ◽  
Male Flowers ◽  
Nectar Rewards ◽  
Toxic Pollen

Abstract Many plants require animal pollinators for successful reproduction; these plants provide pollinator resources in pollen and nectar (rewards) and attract pollinators by specific cues (signals). In a seeming contradiction, some plants produce toxins such as alkaloids in their pollen and nectar, protecting their resources from ineffective pollinators. We investigated signals and rewards in the toxic, protandrous bee-pollinated plant Aconitum napellus, hypothesizing that male-phase flower reproductive success is pollinator-limited, which should favour higher levels of signals (odours) and rewards (nectar and pollen) compared with female-phase flowers. Furthermore, we expected insect visitors to forage only for nectar, due to the toxicity of pollen. We demonstrated that male-phase flowers emitted more volatile molecules and produced higher volumes of nectar than female-phase flowers. Alkaloids in pollen functioned as chemical defences, and were more diverse and more concentrated compared to the alkaloids in nectar. Visitors actively collected little pollen for larval food but consumed more of the less-toxic nectar. Toxic pollen remaining on the bee bodies promoted pollen transfer efficiency, facilitating pollination.

Reproductive biology and nectar production of the Mexican endemicPsittacanthus auriculatus(Loranthaceae), a hummingbird-pollinated mistletoe

Plant Biology ◽  
2015 ◽  
Vol 18 (1) ◽  
pp. 73-83 ◽  
Author(s):  
M. J. Pérez-Crespo ◽  
J. F. Ornelas ◽  
S. Martén-Rodríguez ◽  
A. González-Rodríguez ◽  
C. Lara
Keyword(s):  
Reproductive Biology ◽  
Nectar Production

scholarly journals Linking pollinator efficiency to patterns of pollen limitation: small bees exploit the plant–pollinator mutualism

2018 ◽  
Vol 285 (1880) ◽  
pp. 20180635 ◽  
Author(s):  
Matthew H. Koski ◽  
Jennifer L. Ison ◽  
Ashley Padilla ◽  
Angela Q. Pham ◽  
Laura F. Galloway
Keyword(s):  
Pollen Limitation ◽  
Pollen Deposition ◽  
Pollinator Efficiency ◽  
Flower Visitation ◽  
Female Phase ◽  
Male Phase ◽  
Single Flower ◽  
Floral Visitation ◽  
Low Efficiency ◽  
Plant Pollinator

Seemingly mutualistic relationships can be exploited, in some cases reducing fitness of the exploited species. In plants, the insufficient receipt of pollen limits reproduction. While infrequent pollination commonly underlies pollen limitation (PL), frequent interactions with low-efficiency, exploitative pollinators may also cause PL. In the widespread protandrous herb Campanula americana , visitation by three pollinators explained 63% of the variation in PL among populations spanning the range. Bumblebees and the medium-sized Megachile campanulae enhanced reproductive success, but small solitary bees exacerbated PL. To dissect mechanisms behind these relationships, we scored sex-specific floral visitation, and the contributions of each pollinator to plant fitness using single flower visits. Small bees and M. campanulae overvisited male-phase flowers, but bumblebees frequently visited female-phase flowers. Fewer bumblebee visits were required to saturate seed set compared to other bees. Scaling pollinator efficiency metrics to populations, small bees deplete large amounts of pollen due to highly male-biased flower visitation and infrequent pollen deposition. Thus, small bees reduce plant reproduction by limiting pollen available for transfer by efficient pollinators, and appear to exploit the plant–pollinator mutualism, acting as functional parasites to C. americana . It is therefore unlikely that small bees will compensate for reproductive failure in C. americana when bumblebees are scarce.

scholarly journals Intraspecific Seasonal Variation of Flowering Synchronization in a Heterodichogamous Tree

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1509
Author(s):  
Noemi Tel-Zur ◽  
Tamar Keasar
Keyword(s):  
Genetic Diversity ◽  
Seasonal Variation ◽  
Phase Duration ◽  
Male And Female ◽  
Flowering Synchrony ◽  
Flowering Season ◽  
Hand Pollination ◽  
Female Phase ◽  
Male Phase ◽  
Phase Differences

Heterodichogamous reproduction in plants involves two flowering morphs, reciprocal in their timing of male and female sexual functions. The degree of synchrony in floral sex phase, within and between individuals of each morph, determines the flowers’ potential fertilization partners. Complete within-morph synchrony enables across-morph mating alone, whereas unsynchronized floral sex phases may allow fertilization within a plant individual (geitonogamy) or within a morph. We documented the disruption of flowering synchrony in the heterodichogamous Ziziphus spina-christi towards the end of its seven-month flowering season. This desert tree has self-incompatible, protandrous, short-lived (2-day) flowers that open before dawn (‘Early’ morph) or around noon (‘Late’ morph). We counted flowers in the male and female phase on flowering branches that were sampled monthly during the 2016–2018 flowering seasons. In 2018, we also tagged flowers and followed their sex-phase distributions over two days at the start, middle, and end of the season. The switch to the female phase was delayed at the end-season (November-December), and 74% of the flowers did not develop beyond their male phase. Differences in male-phase duration resulted in asynchrony among flowers within each tree and among trees of both flowering morphs. Consequently, fertilization between trees of the same morph becomes potentially possible during the end-season. In controlled hand-pollination assays, some within-morph fertilizations set fruit. The end-season breakdown of synchronous flowering generates variability within morphs and populations. We suggest that this variability may potentially enable new mating combinations in a population and enhance its genetic diversity.

The reproductive biology of okra. 1. Study of the breeding system in four Abelmoschus species

Euphytica ◽  
1991 ◽  
Vol 53 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Serge Hamon ◽  
Jean Koechlin
Keyword(s):  
Reproductive Biology ◽  
Breeding System

Phenology, pollination, and breeding system of the threatened tree Caesalpinia echinata Lam. (Fabaceae), and a review of studies on the reproductive biology in the genus

Flora ◽  
2009 ◽  
Vol 204 (2) ◽  
pp. 111-130 ◽  
Author(s):  
Laís Angélica Borges ◽  
Mellissa Sousa Sobrinho ◽  
Ariadna Valentina Lopes
Keyword(s):  
Reproductive Biology ◽  
Breeding System ◽  
Caesalpinia Echinata
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