Plant-level fecundity and andromonoecy in three common (Melaleuca styphelioides, M. thymifolia, M. nodosa) and one rare (M. deanei) Melaleuca (Myrtaceae) species of the Sydney region

2014 ◽  
Vol 62 (4) ◽  
pp. 276 ◽  
Author(s):  
Alison Hewitt ◽  
Paul Holford ◽  
Adrian Renshaw ◽  
Anthony Haigh ◽  
E. Charles Morris
Keyword(s):  
Reproductive Performance ◽  
Fruit Set ◽  
Seed Set ◽  
Low Frequency ◽  
Common Species ◽  
Flowering Plants ◽  
Breeding Systems ◽  
Small Populations ◽  
Small Field ◽  
Plant Level

This paper reports plant-level measures of reproductive performance from large and small field populations of the vulnerable species Melaleuca deanei F.Meull. compared with three common species within the genus: Melaleuca nodosa (Sol. ex Gaertn.) Sm., Melaleuca thymifolia Sm. and Melaleuca styphelioides Sm. Measures reported include average seed numbers per capsule and per plant; average fruit loads per plant; the proportion of buds that become flowers and thence fruits (fruit set); the number of ovules per flower and seed : ovule ratios (seed set); and floral morphologies. Results indicate that when M. deanei flowers, bud to flower ratios and flower to fruit ratios are not reduced compared with the congeners or between large and small populations. Seed loads per plant held by fruiting plants were comparable between the species and between large and small populations of M. deanei. Seed to ovule ratios were in the order of 5–9% in M. nodosa; 5–7% in M. styphelioides; 7–10% in M. deanei; and 12–15% in M. thymifolia. Larval herbivory of ovules was recorded in M. nodosa and pre-dispersal seed predation noted in M. thymifolia. Andromonoecy was recorded in two of the species at rates of 0.9–3.1% (M. deanei) and 2.9–7% (M. thymifolia). Results suggest that seed production within smaller populations of M. deanei is poor because of a low frequency of flowering and a low proportion of flowering plants per population, rather than plant-level pollination, fruit- or seed-set barriers. Further study is needed to determine the triggers to flowering, the breeding systems, the extent of clonality and the germination and establishment requirements in these species.

Effect of pollen age on fruit set, fruit weight, and seed set in three orchid species

1998 ◽  
Vol 76 (3) ◽  
pp. 420-427 ◽  
Author(s):  
Heather C Proctor
Keyword(s):  
Laboratory Tests ◽  
Fruit Set ◽  
Seed Set ◽  
Fertilization Success ◽  
Fruit Weight ◽  
Flowering Plants ◽  
Orchid Species ◽  
The Third ◽  
Pollen Longevity ◽  
Species Specific

The length of time that pollen remains viable after being removed from the anther may be subject to species-specific selection pressures, e.g., when the average transit time between anther and stigma is long, long-lived pollen may be favoured. Flowering plants that provide no reward to pollinators are predicted to have relatively long-lived pollen, because pollinators are less likely to immediately revisit flowers of a nonrewarding species. I studied the effect of pollen age on fertilization success in three species of orchids that provide little or no reward. Pollen was aged 0, 1, 2, 4, or 8 days outside of the anther and then placed on the stigmas of conspecific flowers. I collected and weighed all resultant fruits and used a subsampling technique to determine the number of embryonated seeds per fruit and the percentage of all seeds that had embryos. There was no evidence that pollen age affected fruit set, fruit weight, embryonated-seed number, or percentage of embryonated seeds in two species (Calopogon tuberosus (Linn.) Britton and Pogonia ophioglossoides (Linn.) Ker.). In the third, Cypripedium reginae Walt., 8-day-old pollen produced significantly lighter fruits with fewer embryonated seeds; however, the percentage of embryonated seeds was not affected. Although the pollen of these nonrewarding orchids appears to have an impressive life-span, it is difficult to make comparisons with other species because most previous studies have relied on laboratory tests of viability that appear to have little relation to performance of pollen in the field.Key words: pollen longevity, Orchidaceae, reproductive success.

The reproductive capacity of Anigozanthos manglesii D. Don, A. humilis Lindl. and their hybrids in a wild population

1977 ◽  
Vol 25 (4) ◽  
pp. 423 ◽  
Author(s):  
SD Hooper
Keyword(s):  
Seed Germination ◽  
Reproductive Performance ◽  
Fruit Set ◽  
Seed Set ◽  
Wild Population ◽  
Reproductive Capacity ◽  
F1 Hybrids ◽  
Short Term ◽  
Flower Production ◽  
Better Than

The flower production, fruit set, seed set and seed germination of parental and hybrid Anigozanthos individuals from the Gingin cemetery, Western Australia, were investigated to establish whether differences in reproductive capacity could have been responsible for observed short-term numerical changes in the population. A. manglesii had a six- to ninefold reproductive advantage over A. humilis due to greater seed set and better germination. F1 hybrids and backcrosses had reproductive capacities equivalent to or slightly better than A. humilis. The agreement between calculated reproductive capacity values and the trend of numerical changes in the cemetery supports the conclusion that differences in reproductive performance have played a significant role in the short-term dynamics of the population.

scholarly journals Spatial structure and inbreeding depression in slickspot peppergrass, Lepidium papilliferum (Brassicaceae)

Botany ◽  
2008 ◽  
Vol 86 (9) ◽  
pp. 1002-1008 ◽  
Author(s):  
Stephanie A. Billinge ◽  
Ian C. Robertson
Keyword(s):  
Spatial Structure ◽  
Inbreeding Depression ◽  
Reproductive Performance ◽  
Fruit Set ◽  
Leaf Length ◽  
Small Populations ◽  
Hand Pollination ◽  
Large Populations ◽  
Pollen And Seed Dispersal ◽  
Close Relatives

In plants with limited pollen and seed dispersal, populations are often spatially structured such that neighboring individuals are more closely related to one another than to distant individuals. Mating among close relatives, including selfing, may lead to a reduction in reproductive performance through the effects of prezygotic mating barriers and inbreeding depression. Studying 11 populations of slickspot peppergrass, Lepidium papilliferum (L.F. Hend.) A. Nels. and J.F. Macbr (Brassicaceae), a rare mustard endemic to southwestern Idaho, we investigated whether small populations (16–746 flowering individuals) exhibit spatial structure as previously reported for large populations (>3000 flowering individuals). Through hand-pollination experiments we found that percent fruit set increased with increasing distance between parents up to a distance of 3 m, and declined slightly but nonsignificantly at greater outcrossing distances. Self-pollinated plants produced little or no fruit. Germination of seeds from the hand-pollination experiment revealed signs of inbreeding depression in the offspring. Specifically, leaf length of developing seedlings increased significantly as a function of outcrossing distance. Total leaf number showed a similar, yet statistically nonsignificant, response to outcrossing distance. Overall, our experiments reveal spatial structuring and suggest the occurrence of inbreeding depression in small populations of L. papilliferum.

scholarly journals Comparative floral ecology and breeding systems between sympatric populations of Nothoscordum bivalve and Allium stellatum (Amaryllidaceae)

2020 ◽  
Vol 26 ◽  
Author(s):  
Daniel S Weiherer ◽  
Kayla Eckardt ◽  
Peter Bernhardt
Keyword(s):  
Fruit Set ◽  
Seed Set ◽  
Geometric Mean ◽  
Floral Biology ◽  
Breeding Systems ◽  
Outbreeding Depression ◽  
Sympatric Populations ◽  
Closely Related Species ◽  
Floral Ecology ◽  
Self Pollination

We compared the floral biology of two sympatric populations of closely related species over two seasons. In 2018, Nothoscordum bivalve (L.) Britton bloomed from April 23 to May 7 and Allium stellatum Nutt. Ex Ker Gawl bloomed from August 28 to October 4. Erect, white flowers of N. bivalve were scented and had septal nectaries. Erect, pink-purple flowers of A. stellatum had septal nectaries, no discernible scent, and a style that lengthened over the floral lifespan. Both species were pollinated by bees with the most common geometric mean of body dimensions between 2-3 mm. Most bees carried pure loads of the host plant’s pollen. Despite phenological isolation, the two herbs shared three bee species. Allium stellatum was also pollinated by the beetle Chauliognathus pensylvanicus DeGeer (Cantharidae). Tepal nyctinasty ensured mechanical self-pollination in N. bivalve. Protandry occurred in A. stellatum. In N. bivalve, the proportion of pollen tubes penetrating ovules was highest in bagged, self-pollinating flowers. However, in A. stellatum it was highest in exposed flowers and hand cross-pollinated flowers. Fruit set in N. bivalve was highest in exposed and bagged, self-pollinating flowers. In A. stellatum, fruit set was highest in both exposed and hand cross-pollinated flowers. Seed set was the same among all treatments for both species. We interpret these results as evidence that A. stellatum is a self-incompatible, obligate outcrosser. Nothoscodum bivalve is a self-compatible, obligate inbreeder employing mechanical and insect-mediated self-pollination. Outbreeding depression appears to occur in N. bivalve with a partial trend towards intraspecific cross-incompatibility.

The Breeding Systems of Three Cooccurring Legumes: Dillwynia hispida, Dillwynia uncinata and Pultenaea densifolia (Leguminosae, Papilionoideae)

1990 ◽  
Vol 38 (2) ◽  
pp. 207 ◽  
Author(s):  
CL Gross
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Experiments ◽  
Fruit Set ◽  
Seed Set ◽  
Breeding Systems ◽  
High Pollen ◽  
Pollen Vectors ◽  
Esterase Production ◽  
Scanning Electron

The breeding systems of Dillwynia hispida Lindley, D. uncinata (Turcz.) J. Black and Pultenaea densifolia F. Muell. were determined using glasshouse trials and field experiments. Each species is self-incompatible and thus relies on pollen vectors to effect seed-set. Calculations of pollen-ovule ratios are compatible with this conclusion. Increase in the age of pollen led to a decline in fruit-set, which was more pronounced in Dillwynia uncinata than D. hispida or P. densifolia. In this study, Pultenaea densifolia pollen was never more than 60% viable which may explain the extremely high pollen-ovule ratio of this species. In all three species, esterase production on stigmas implied that they were fully receptive by day 3 of flowering. Stigma morphologies were assessed by scanning electron microscopy and the results used to discuss their incompatibility mechanisms.

scholarly journals Phloem-Feeding Herbivores Affect Floral Development and Reproduction in the Etruscan Honeysuckle (Lonicera etrusca Santi)

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 815
Author(s):  
Sandra V. Rojas-Nossa ◽  
José María Sánchez ◽  
Luis Navarro
Keyword(s):  
Fruit Set ◽  
Floral Development ◽  
Seed Set ◽  
Wild Populations ◽  
Ecological Processes ◽  
Trade Offs ◽  
Complex Landscape ◽  
Fruit And Seed Set ◽  
Phloem Feeding ◽  
Growth And Reproduction

Floral development depends on multifactor processes related to genetic, physiological, and ecological pathways. Plants respond to herbivores by activating mechanisms aimed at tolerating, compensating, or avoiding loss of biomass and nutrients, and thereby survive in a complex landscape of interactions. Thus, plants need to overcome trade-offs between development, growth, and reproduction vs. the initiation of anti-herbivore defences. This study aims to assess the frequency of phloem-feeding herbivores in wild populations of the Etruscan honeysuckle (Lonicera etrusca Santi) and study their effects on floral development and reproduction. The incidence of herbivory by the honeysuckle aphid (Hyadaphis passerinii del Guercio) was assessed in three wild populations of the Iberian Peninsula. The effect of herbivory on floral morphology, micromorphology of stigmas and pollen, floral rewards, pollination, and fruit and seed set were studied. The herbivory by aphids reduces the size of flowers and pollen. Additionally, it stops nectar synthesis and causes malformation in pollen and microstructures of stigmas, affecting pollination. As a consequence, fruit set and seed weight are reduced. This work provides evidence of the changes induced by phloem-feeding herbivores in floral development and functioning that affect the ecological processes necessary to maintain the reproductive success of plants.

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

1993 ◽  
Vol 9 (2) ◽  
pp. 199-211 ◽  
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.

scholarly journals Florivory and sex ratio in Annona dioica St. Hil. (Annonaceae) in the Pantanal at Nhecolândia, southwestern Brazil

2006 ◽  
Vol 20 (2) ◽  
pp. 405-409 ◽  
Author(s):  
Hipólito Ferreira Paulino Neto ◽  
Reinaldo Chaves Teixeira
Keyword(s):  
Sex Ratio ◽  
Fruit Set ◽  
Flowering Plants ◽  
The Mean ◽  
Male Flowers

Annona dioica St. Hil. is a species that grows to approximately 2 m tall and is very widespread in the cerrados. Individual plants of this androdioecious species produce numerous hermaphroditic or male flowers, but few fruits. The aim of this study was to determine the sex ratio among the plants and to compare the frequency of herbivory between male and hermaphroditic flowers. The fieldwork was done by studying flowering plants in grasslands used as pasture for cattle at Fazenda Nhumirim. One hundred and forty-seven male plants and 71 hermaphroditic plants were examined and produced a total of 194 and 94 flowers, respectively, during the study period. The male:hermaphrodite sex ratio was 2.07:1, and was similar to the male:hermaphrodite flower ratio of 2.06:1. The frequency of florivory rate in hermaphrodites was significantly higher than in male flowers (33.0%, n = 31, and 25.7%, n = 50, respectively; G = 14.83; d.f. = 1; p < 0.001). The mean fresh weights of male and hermaphroditic flowers were significantly different (8.38 ± 2.40 g vs. 6.93 ± 2.68 g, respectively; 0 ± SEM; n = 50 each; t = 2.479; d.f. = 49; p = 0.017). These results indicate that the low fruit set in this species can be explained by the sex ratio, the greater herbivory of hermaphroditic flowers and the probable absence of pollinators.

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