Pollination of Pagamea duckei Standl. (Rubiaceae): a functionally dioecious species

The floral biology, pollination and breeding system of Pagamea duckei Standl. (Rubiaceae) were studied at the Reserva Biológica da Campina, Manaus, Amazonas, Brazil. Floral morphology suggested that P. duckei is a distylous species. However, crossing experiments revealed that it is functionally dioecious. The flowers are actinomorphic, yellowish, produce nectar and a sweet odor, which is more intense in the morning. Anthesis started in the morning between 5.00 and 6.00 AM and extended until dusk, when the corolla tube abscissed. The flowers were visited mostly by bees of the genus Melipona. Pagamea duckei is not agamospermic and thus needs pollen vectors for effective pollination. The results of this study strengthen the idea that, in Pagamea, species with distylous flower morphology are actually functionally dioecious.

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Floral biology of Hemigenia and Microcorys (Lamiaceae)

Australian Journal of Botany ◽

10.1071/bt04063 ◽

2005 ◽

Vol 53 (2) ◽

pp. 147 ◽

Cited By ~ 3

Author(s):

Greg Guerin

Keyword(s):

Connective Tissue ◽

Reproductive Isolation ◽

Floral Morphology ◽

Corolla Tube ◽

Floral Biology ◽

Pollen Deposition ◽

Field Observations ◽

Bird Pollination ◽

Insect Pollinators

The floral morphology and pollination of Hemigenia R.Br. and Microcorys R.Br. (Lamiaceae) were examined in the field and laboratory. The protandrous flowers have tubular, two-lipped corollas. Nine floral morphotypes are described. The stamens may be completely sterile (staminodal) or have one theca reduced or absent. The anthers typically have elongated connective tissue and are mobile on the filament. When the lower end of the anther is pushed, the upper end is levered towards the mouth of the corolla tube, hence dusting the pollinator precisely where receptive stigmas will later touch. Bearding on the anthers of the adaxial stamens catches adjacent anthers so that they lever in unison. Staminodes guide insect pollinators into the throat to allow precise pollen dusting. Detailed field observations show that bees and flies are the principle pollinators of most species. Floral morphologies are related to pollinator castes, and reproductive isolation and efficiency is enhanced by precise pollen deposition. Bird pollination is likely to have arisen independently in several taxa. The floral arrangement of these taxa is superficially similar but the syndrome is achieved through different anatomy.

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Adaptive response of extreme epiphyte Tillandsia species (Bromeliaceae) is demonstrated by different sexual reproduction strategies in the Brazilian Chaco

Botanical Journal of the Linnean Society ◽

10.1093/botlinnean/boz104 ◽

2019 ◽

Vol 192 (4) ◽

pp. 840-854

Author(s):

Aline C Gomes ◽

Bruno H S Ferreira ◽

Camila S Souza ◽

Luan M M Arakaki ◽

Camila Aoki ◽

...

Keyword(s):

Breeding System ◽

Reproductive Strategies ◽

Extreme Environments ◽

Extreme Environment ◽

Floral Biology ◽

Reproduction Strategies ◽

Pollen Vectors ◽

Self Compatibility ◽

Floral Visitors ◽

Selection For

Abstract Some epiphytes are adapted to extreme environments with the ability to survive drought as a result of their morphological (xeromorphism), anatomical (foliar trichomes or scales) and physiological features. In contrast to vegetative features, they may have diverse sexual reproductive strategies. Here we compared the flowering morphology, floral biology, breeding system and pollinators of Tillandsia duratii, T. loliacea and T. recurvifolia (Bromeliaceae) adapted to an extreme environment, the Brazilian Chaco. Tillandsia duratii and T. recurvifolia flower for 5–6 months, whereas T. loliaceae flowers for 11 months, mainly in the dry season, with low to high flowering overlap between them. Although these species generally show similar flowering morphology, they differ in size, colour, odour and/or floral functionality, suggesting non-sharing of pollinators among them. Bimodal pollination occurs in T. duratii (bees, moths other than hawkmoths) and T. recurvifolia (butterflies, hummingbirds); in T. loliacea, we recorded no floral visitors. Tillandsia recurvifolia is self-incompatible, has flowers which approach herkogamy and protandry, and depends on pollen vectors for fruit set. The other two species show reverse herkogamy, autonomous self-pollination and self-compatibility (mixed breeding system); therefore, pollinators are not required. The disparity in reproductive strategies among the three species suggests the possibility of selection for diverse modes of reproduction.

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Pollination and floral biology of Adonis vernalis L. (Ranunculaceae) – a case study of threatened species

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.2014.001 ◽

2014 ◽

Vol 83 (1) ◽

pp. 29-37 ◽

Cited By ~ 7

Author(s):

Bożena Denisow ◽

Małgorzata Wrzesień ◽

Anna Cwener

Keyword(s):

Threatened Species ◽

Breeding System ◽

Pollen Viability ◽

Management Strategies ◽

Reproductive Potential ◽

Floral Biology ◽

Pollination Syndrome ◽

Compact Range ◽

Pollen Vectors ◽

Pollination Systems

Although the knowledge of pollination systems of rare and threatened species is one of the principles for development of optimal conservation and management strategies, the data about their pollination requirements are scarce or incomplete. Different problems are listed (xerothermic habitat disappearance, overgrowing of patches, plant biology i.e., slow plant growth, problems with seed germination) among the possible causes of Adonis vernalis being threatened, but until now no consideration was given to the flowering biology and pollination.The observations of flowering biology of A. vernalis (Ranunculaceae), a clonal species, were conducted in an out-of-compact-range population, in the Lublin Upland, Poland (51°18'55" N, 22°38'21" E), in 2011–2013. The reproductive potential of A. vernalis is related to the population age structure, pollination syndrome, and breeding system. The flowers exhibit incomplete protogyny. The dichogamy function is supported by different (biological, morphological) mechanisms. Stigma receptivity occurred about one day before anthers started shedding self-pollen, and pollen viability was increasing gradually during the flower life-span (66.3% in distal anthers vs. 77.3% in proximal). The decrease in pollen production and in pollen viability coincided with the lowest degree of seed set, irrespective of the pollination treatment. Pollen vectors are necessary for efficient pollination, as the proportion of pistils setting fruits after open pollination (41–82.1%) was significantly higher compared to spontaneous self-pollination (only 5.5–12.3%). The pollination requirements together with pollen/ovule ratio (P/O = 501) indicate a facultative xenogamous breeding system in A. vernalis. Therefore, in the conditions of the global lack of pollinators, improper pollination may weaken the population by leading to a decrease in the proportion of recombinants, and in addition to other factors, may accelerate extinction of small A. vernalis populations.

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Pollination ecology of Caryocar brasiliense (Caryocaraceae) in Central Brazil cerrado vegetation

Journal of Tropical Ecology ◽

10.1017/s0266467400007173 ◽

1993 ◽

Vol 9 (2) ◽

pp. 199-211 ◽

Cited By ~ 55

Author(s):

Rogério Gribel ◽

John D. Hay

Keyword(s):

Breeding System ◽

Fruit Set ◽

Seed Set ◽

Floral Biology ◽

Cerrado Vegetation ◽

Central Brazil ◽

Glossophaga Soricina ◽

Caryocar Brasiliense ◽

Anoura Geoffroyi ◽

Phyllostomus Discolor

ABSTRACTThe floral biology, breeding system and pollination of Caryocar brasiliense were studied in the cerrado vegetation of Central Brazil. The large, yellowish-cream, brush-like flowers are pollinated mainly by glossophagine bats (Glossophaga soricina and Anoura geoffroyi). Three non-glossophagine bats (Phyllostomus discolor, Vampyrops lineatus and Carollia perspicillata) and two short probosisced hawk moths (Erinyis ello and Pseudosphinx tetrio) may also act as occasional pollinators. Caryocar brasiliense is self-compatible although it sets significantly more fruits when crossed than when selfed. The natural fruit set (fruit/flower ratio) and seed set (seed/ovule ratio) are 3.1% and 1.0% respectively. Most of the fruits and seeds are formed through the action of the flower visitors, despite the fact that about 20% of the non-visited flowers receive self pollen on at least one stigma.

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FLORAL BIOLOGY AND BREEDING SYSTEM IN CARDIOCRINUM GIGANTEUM (LILIACEAE), A PERENNIAL BULBIFEROUS HERB IN YUNNAN PROVINCE IN CHINA

Acta Horticulturae ◽

10.17660/actahortic.2013.977.14 ◽

2013 ◽

pp. 133-142

Author(s):

W.L. Guan ◽

Y.F. Li ◽

X. Chen ◽

S.F. Li ◽

J. Song

Keyword(s):

Breeding System ◽

Yunnan Province ◽

Floral Biology

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Pollination and Seed Set of Banksia spinulosa: Evidence for Autogamy

Australian Journal of Botany ◽

10.1071/bt9880633 ◽

1988 ◽

Vol 36 (6) ◽

pp. 633 ◽

Cited By ~ 15

Author(s):

G Vaughton

Keyword(s):

New England ◽

Breeding System ◽

Seed Weight ◽

National Park ◽

Fruit Set ◽

Seed Set ◽

Pollen Vectors ◽

Specific Variation ◽

Number Of Seeds

The breeding system of Banksia spinulosa var. neoanglica in the New England National Park was examined by excluding pollen vectors and hand pollinating inflorescences. Fruit set of xenogamous and open inflorescences was greater than geitonogamous and autogamous treatments, although not all differences were significant. No differences were found in the number of seeds per follicle or seed weight between treatments. A reduced number of follicles and smaller seeds occurred in the apical third of inflorescences in all treatments. This report of autogamous seed set contrasts with previous findings for this species and indicates intra-specific variation in the breeding system.

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Floral biology and late-acting self-incompatibility in Jacaranda racemosa (Bignoniaceae)

Australian Journal of Botany ◽

10.1071/bt04221 ◽

2006 ◽

Vol 54 (3) ◽

pp. 315 ◽

Cited By ~ 21

Author(s):

Nelson S. Bittencourt ◽

João Semir

Keyword(s):

Breeding System ◽

Histological Analysis ◽

Floral Biology ◽

Self Incompatibility ◽

Flower Visitation ◽

Hand Pollination ◽

Natural Pollination ◽

Ovule Penetration ◽

Incompatibility Barrier

Breeding-system studies have been conducted with 38 of the approximately800 species of Bignoniaceae, and self-incompatibility was found in 31 of these. In species for which the site of self-incompatibility barrier was studied, self-pollinated flowers consistently failed to develop into fruits, even though pollen tubes grew down to the ovary and penetrated most of the ovules. In this study, we have investigated the floral biology and the breeding system in Jacaranda racemosa Chamisso, with hand-pollination experiments and the histology of post-pollination events. Flower anthesis lasted 1–3 days, and although the frequency of flower visitation was extremely low, natural pollination seemed to be effected mainly by medium-sized bees. Because the conspicuous staminodium favours eventual pollination by small bees, a possible role of the staminodium in the increase of potential pollinators is suggested. Hand-pollinations indicated that J. racemosa is a self-sterile species. Histological analysis of post-pollination events indicated the occurrence of a kind of late-acting self-incompatibility in which the processes of ovule penetration, fertilisation and endosperm initiation were slower in selfed than in crossed pistils. Until the time of self-pollinated pistil abscission, no signs of endosperm malfunction or proembryo development were observed in selfed pistils. Therefore, inbreeding depression is an unlikely explanation for self-sterility in J. racemosa.

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