Disassortative pollination in the distylous plant Jepsonia heterandra

1974 ◽  
Vol 52 (11) ◽  
pp. 2401-2406 ◽  
Author(s):  
Fred R. Ganders
Keyword(s):  
Seed Set ◽  
Adaptive Significance ◽  
Pollen Loads ◽  
Self Pollination

Stigmatic pollen loads were analyzed from naturally pollinated intact and emasculated pin- and thrum-form flowers of Jepsonia heterandra. Observed pollen loads on stigmas of emasculated flowers were compared with expected loads based on random pollination. Observed pollen loads indicated that 13.2% disassortative pollination occurred in the pin form and 43.5% disassortative pollination in the thrum form. Pollen loads from intact flowers indicated that much more self pollination and geitonogamy takes place in the pin form than in the thrum form. In this species, distyly effectively promotes phenotypic disassortative pollination.It is suggested that the adaptive significance of distyly m a diallelic self-incompatible species is that the resultant disassortative pollination increases seed set in the population.

Pollen flow in distylous populations of Amsinckia (Boraginaceae)

1976 ◽  
Vol 54 (22) ◽  
pp. 2530-2535 ◽  
Author(s):  
Fred R. Ganders
Keyword(s):  
Pollen Flow ◽  
Progeny Testing ◽  
Self Incompatibility ◽  
Disassortative Mating ◽  
Pollen Loads ◽  
Self Pollination ◽  
Incompatibility System ◽  
Total Pollen

Stigmatic pollen loads were analyzed from naturally pollinated pin and thrum form flowers of Amsinckia douglasiana and A. vernicosa var. furcata. Pin stigmas captured more total pollen than thrum stigmas. Pins experienced either net self-pollination or random pollination. Thrum stigmas experienced significant disassortative pollination. Comparing pollen loads from intact and emasculated thrum flowers of A. douglasiana indicated that self-pollination and geitonogamy were relatively unimportant in the pollination of the thrum form. The level of disassortative pollination of A. vernicosa var. furcata does not appear to be high enough to account for the level of disassortative mating observed by progeny testing, suggesting that this species may possess an incomplete stylar self-incompatibility system such as has been reported in A. grandiflora.

Electrophoretic evidence supporting self-incompatibility in Lotus corniculatus

1980 ◽  
Vol 58 (6) ◽  
pp. 712-716 ◽  
Author(s):  
Shirley Dobrofsky ◽  
W. F. Grant
Keyword(s):  
Gel Electrophoresis ◽  
Seed Set ◽  
Polyacrylamide Gel Electrophoresis ◽  
Lotus Corniculatus ◽  
Polyacrylamide Gel ◽  
Self Incompatibility ◽  
Banding Patterns ◽  
Protein Subunits ◽  
Self Pollination

Self-incompatibility, a prefertilization event, and self-sterility, a postfertilization event, have both been suggested as causes for differences in seed set between cross- and self-pollinated florets in Lotus corniculatus L. Ovary protein subunits of selfed, crossed, and unpollinated florets of L. corniculatus cv. Mirabel were studied using polyacrylamide gel electrophoresis. Banding patterns differed for all three conditions. Ovary protein differences were found prior to the time fertilization is known to occur, thereby providing evidence that self-incompatibility is at least partially responsible for the reduced seed set after self-pollination.

Bird and Mammal pollen vectors in Banksia communities at Cheyne Beach, Western Australia

1980 ◽  
Vol 28 (1) ◽  
pp. 61 ◽  
Author(s):  
SD Hopper
Keyword(s):  
Western Australia ◽  
Adaptive Significance ◽  
Flowering Plants ◽  
House Mice ◽  
Functional Roles ◽  
Pollen Loads ◽  
Pollen Vectors ◽  
Autumn Flowering

A study of several autumn-flowering plants at Cheyne Beach was undertaken to compare pollen loads of their bird and mammal vectors and to investigate hypotheses concerning adaptations for bird and mammal pollination in Banksia. New Holland honeyeaters, white-cheeked honeyeaters, western spinebills and honey possums were all found to carry pollen of species of Banksia, Adenanthos, Lambertia (Proteaceae), Beaufortia and Calothamnus (Myrtaceae), whereas southern bush rats and house mice carried virtually none. Honeyeaters carried significantly larger pollen loads of the Proteaceae species than did honey possums. The honey possums carried the largest loads of Myrtaceae pollen. The loads on honey possums and southern bush rats may have been underestimated because these mammals were live-trapped and may have preened themselves prior to sampling for pollen. It was found that the two dominant banksias had divergent floral characteristics, some of which previous authors had suggested were adaptations to either bird or mammal pollination (e.g. straight styles in B. baxteri as against hooked styles in B. occidentalis). However, birds and mammals appeared to feed without preference on, and carry the pollen of, both species. The net effect of the divergent characteristics of the two banksias was that B. occidentalis transferred more pollen to vertebrate vectors and set more seed per inflorescence than did B. baxteri. Further work is needed to clarify the functional roles and adaptive significance of floral characteristics in these and other banksias.

The Breeding Systems of Stylidium graminifolium and Stylidium productum (Stylidiaceae)

1990 ◽  
Vol 38 (2) ◽  
pp. 217 ◽  
Author(s):  
AJ Willis ◽  
JE Ash
Keyword(s):  
Breeding System ◽  
Seed Set ◽  
Breeding Systems ◽  
The South ◽  
Pollination Experiments ◽  
Australian Species ◽  
South West ◽  
Self Pollination ◽  
Incompatibility System ◽  
Close Relationship

The breeding systems of Stylidiurn grarninifolium and S. producturn (= S. grarninifoliurn var. caulescens) were studied by observing the phenology of individual flowers and inflorescences, and relating the data to a series of pollination experiments within and between the species. Inter-specific pollinations yielded similar levels of seed-set to crosses within the species indicating a close relationship between the taxa. Self-pollination of either species is uncommon; however, when it occurs, the majority of selfed ovules are aborted post-zygotically, probably by a system of recessive lethals, as there is no indication of an incompatibility system. It is concluded that the breeding systems of S. grarninifoliurn and S. productum, two of the few eastern Australian species, are similar to those of many Stylidiurn species from the south-west, casting doubt upon hypotheses that the breeding system has led to high rates of speciation in the south-west.

scholarly journals Comparative reproduction mechanisms of three species of Ocimum L. (Lamiaceae)

2016 ◽  
Vol 69 (1) ◽  
Author(s):  
Matthew Oziegbe ◽  
Temitope Olatayo Kehinde ◽  
Joshua Olumide Matthew
Keyword(s):  
Reproductive System ◽  
Seed Set ◽  
Ocimum Basilicum ◽  
The Self ◽  
Self Pollination ◽  
Insect Visitation ◽  
Open Treatment ◽  
Fruit And Seed Set

<em>Ocimum</em> species have a combination of reproductive system which varies with the locality and cultivar. We have studied here the reproductive mechanisms of five variants of three <em>Ocimum</em> species in Nigeria, namely: <em>Ocimum canum</em> Sims., <em>O. basilicum</em> L., and <em>O. americanum</em> L. Flowers from each variant were subjected to open and bagged pollination treatments of hand self-pollination, spontaneous self-pollination and emasculation. All open treatments of the five <em>Ocimum</em> variants produced more fruit and seed than the corresponding bagged treatments. The two <em>O. canum</em> variants and <em>O. basilicum</em> ‘b<span><sub>1</sub></span>’ produced high fruit and seed set in the open and bagged treatments of spontaneous self-pollination. <em>Ocimum basilicum</em> ‘b<span><sub>2</sub></span>’ and <em>O. americanum</em> produced higher fruit and seed set in the self-pollination open treatment but significantly lower fruit and seed set in the bagged treatment. Fewer fruit and seeds were produced in the emasculated open treatments but none in the emasculated bagged treatments of the five <em>Ocimum</em> variants. The floral foragers comprising of bees, wasps and butterflies visited the <em>Ocimum</em> species to collect pollen or nectar in the open treatments. The two <em>O. canum</em> variants and <em>O. basilicum</em> ‘b<span><sub>1</sub></span>’ variant reproduced mainly through autogamy but <em>O. basilicum</em> ‘b<span><sub>2</sub></span>’ and <em>O. americanum</em> showed mixed reproduction of autogamy and outcrosssing. Insect visitation to the flowers enhanced pollination resulting in higher fruit and seed set in all the <em>Ocimum</em> species studied.

Pollination and reproductive success in the gynodioecious endemic Thymus loscosii (Lamiaceae)

2005 ◽  
Vol 83 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Maria Renée Orellana ◽  
Anna Maria Rovira ◽  
Cèsar Blanché ◽  
Maria Bosch
Keyword(s):  
Reproductive Success ◽  
Seed Quality ◽  
Seed Set ◽  
Pollen Deposition ◽  
Pollinator Visitation ◽  
Heterospecific Pollen ◽  
Pollen Loads ◽  
Visual Attraction ◽  
Insect Exclusion ◽  
Two Populations

Sexual dimorphism can have implications in the reproductive biology of gynodioecious species, affecting sex fitness. We explored the effects of flower sex on pollination visitation rates and pollinator efficiency in terms of stigmatic pollen loads, as well as on quantitative and qualitative aspects of reproductive success in two populations of Thymus loscosii Willk. (Lamiaceae) endemic to the northeastern Iberian Peninsula. We also assessed the dependence of T. loscosii on insect pollination in both hermaphrodite and female plants by performing an insect exclusion test. Apis mellifera and different species of Bombylidae were the most frequent pollinators (68% of approaches to studied plots and 93% of total visited flowers). Hermaphrodite plants received more visits than female ones, possibly as a response to visual attraction, since flowers of the former are larger. Conspecific pollen deposition was higher on stigmas of hermaphrodite flowers than on those of females; in contrast, female stigmas received more heterospecific pollen loads, notably higher in one population. Despite these differences, seed set from open-pollinated flowers was similar in both sexes and in both populations, and relatively low (around 0.5–1 nutlet per fruiting calyx, on average). Thymus loscosii is self-compatible as it was able to produce seeds by spontaneous selfing, but at very low rates, indicating that it is insect-dependent for pollination. In addition, bagged female flowers also set seeds formed by apomitic mechanisms. In general, seeds from females were slightly heavier and began to germinate earlier and at higher rates than those from hermaphrodites, even those formed by apomixis. These results suggest that female plants enjoy a resource allocation advantage that allows increased seed quality and contributes to the maintenance of gynodioecy.Key words: gynodioecy, pollinator visitation, pollen loads, seed set, sex fitness, Thymus loscosii.

Pollination biology of Syngonanthus elegans (Eriocaulaceae - Poales)

2009 ◽  
Vol 57 (2) ◽  
pp. 94 ◽  
Author(s):  
Aline Oriani ◽  
Paulo T. Sano ◽  
Vera L. Scatena
Keyword(s):  
Seed Set ◽  
Germination Percentage ◽  
Pollination Biology ◽  
Floral Resources ◽  
Minor Role ◽  
Seedling Vigour ◽  
Pollinator Behaviour ◽  
System A ◽  
Self Pollination ◽  
A Minor

Studies on the pollination biology of Eriocaulaceae are scarce although particularly interesting because of its inclusion in the Poales, a predominantly wind-pollinated order. The pollination biology of Syngonanthus elegans (Bong.) Ruhland was studied during two annual flowering periods to test the hypothesis that insect pollination was its primary pollination system. A field study was carried out, including observations of the morphology and biology of the flowers, insect visits and pollinator behaviour. We also evaluated seed set, seed germination and seedling development for different pollination modes. Although seeds were produced by self-pollination, pollination by small insects contributed most effectively to the reproductive success of S. elegans, resulting in the greatest seed set, with the highest germination percentage and optimum seedling vigour. The floral resources used by flower visitors were pollen and nectar that was produced by staminate and pistillate flowers. Self-pollination played a minor role and its consequence was inbreeding depression.

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