Self-compatibility and floral biology in subdioecious Wurmbea dioica (Colchicaceae)

2003 ◽  
Vol 51 (1) ◽  
pp. 39 ◽  
Author(s):  
Glenda Vaughton ◽  
Mike Ramsey
Keyword(s):  
Inbreeding Depression ◽  
Seed Set ◽  
Developmental Stages ◽  
Floral Biology ◽  
Seed Abortion ◽  
Temporal Separation ◽  
Gender Dimorphism ◽  
Genetic Method ◽  
Floral Longevity ◽  
Self Compatibility

Dioecy has long been interpreted as a mechanism to avoid self-fertilisation and the negative effects of inbreeding depression. We determined relative self-compatibility and temporal overlap of male and female functions for hermaphrodites in subdioecious Wurmbea dioica to assess the role of selfing in the maintenance of gender dimorphism. Plants were self-compatible but did not self-pollinate autonomously. Self- and open-pollinated hermaphrodites had high seed abortion and low seed set, whereas crossed hermaphrodites and crossed and open females had low seed abortion and high seed set. For selfed hermaphrodites, abortion occurred over a range of developmental stages and was negatively related to seed set. Inbreeding depression for seed set varied extensively among plants, averaging 0.56. Despite high inbreeding depression, substantial selfing occurred in open-pollinated hermaphrodites (S = 0.76), as estimated by a non-genetic method. Flowers were protogynous, although temporal separation of male and females functions was limited because anthers began to dehisce shortly after flowers opened. Anther dehiscence was staggered over 4 days and floral longevity, pollen longevity and stigma receptivity were prolonged, thus providing considerable opportunities for pollinator-mediated self-pollination. Our findings indicate that high levels of selfing and subsequent abortion of selfed embryos due to early acting inbreeding depression are important factors maintaining gender dimorphism in W. dioica.

Assessing the effect of inbreeding and long-distance gene flow on the invasive potential of Senecio pterophorus (Asteraceae)

2008 ◽  
Vol 56 (6) ◽  
pp. 539 ◽  
Author(s):  
Lidia Caño ◽  
Josep Escarré ◽  
José M. Blanco-Moreno ◽  
F. Xavier Sans
Keyword(s):  
Gene Flow ◽  
Inbreeding Depression ◽  
Seed Set ◽  
Spanish Population ◽  
Alien Invasive Species ◽  
Invasive Potential ◽  
Long Distance ◽  
Introduced Range ◽  
Self Compatibility ◽  
Introduced Population

Alien invasive species undergo genetic bottlenecks during the colonisation of new areas that can lead to a loss of genetic variation within populations and to subsequent reproductive constraints. We analysed the self-compatibility and the effects of inbreeding and inter-population gene flow in the fitness of one native and one introduced population of the invasive Senecio pterophorus D.C. Plants were self-pollinated and outcrossed within families, within populations, between local populations and between populations located in the native and introduced range. Self-pollinated individuals from both populations produced almost no seeds, thus revealing self-incompatibility. High family-level variation was observed in the effect of pollination treatment on seed set and total fitness. Overall, in the Spanish population, related crosses produced fewer seeds and lower germination rates than unrelated crosses. In the South African population, inbreeding depression affected the probability of flowering. Heterosis was found to affect seed set in both populations and growth and mean pre-reproductive time in the Spanish population. We discuss the effects of the incompatibility system, inbreeding depression and long-distance gene flow within the introduced population with respect to the invasive potential of S. pterophorus in north-eastern Spain.

Self-incompatibility, Seed Abortion and Clonality in the Breeding Systems of Several Western Australian Drosera species (Droseraceae)

1997 ◽  
Vol 45 (1) ◽  
pp. 191 ◽  
Author(s):  
Helen M. Stace ◽  
Lin Chen ◽  
Sidney H. James
Keyword(s):  
Pollen Tube ◽  
Inbreeding Depression ◽  
Pollen Tube Growth ◽  
Sampling Method ◽  
Seed Set ◽  
Breeding Systems ◽  
Seed Abortion ◽  
Self Incompatibility ◽  
Position Effects ◽  
Western Australian

Western Australian Drosera L. species include one annualand many tuberous and pygmy perennials. In 20 species or subspecies, 17 taxawere self-incompatible (SI) and three were self-compatible (SC), as assessedby patterns of seed set and pollen tube growth. All SI species were clonal(tubers or gemmae), but two SC species were clonal (gemmae) and one wasannual. Self-pollen tube inhibition confirmed that SI species werepre-zygotically self-sterile. The sites of SI pollen tube inhibition variedfrom early (stigmatic) to late (stylar, placental, ovular), which suggestscontinuing evolution in the expression of the SI response. Self-compatiblespecies showed little inbreeding depression, but SI species showedconsiderable inbreeding depression as measured by seed abortion. In the threespecies tested, open-pollinated capsules were typically more fecund thanhand-pollinated capsules. In D. glanduligera Lehm., thismight represent position effects in an inflorescence that were reflected inthe sampling method. In other species, however, this might also reflectbiparental inbreeding depression in the glasshouse plants. Interspecificcrosses between D. tubaestylis N.Marchant & A.Lowrie(n = 14) and D. rosulataLehm. (n = 13) were slightly successful, with nopollen–pistil incompatibility interaction, but with extensive seedabortion. This is the first report of SI in Droseraceae.

Floral phenology in relation to pollination and reproductive output in Commelina caroliniana (Commelinaceae)

2008 ◽  
Vol 56 (1) ◽  
pp. 59 ◽  
Author(s):  
Veenu Kaul ◽  
A. K. Koul
Keyword(s):  
Rainy Season ◽  
Reproductive Output ◽  
Seed Set ◽  
Floral Biology ◽  
The Third ◽  
Cross Pollination ◽  
Large Numbers ◽  
Floral Phenology ◽  
Self Compatibility ◽  
Fruit And Seed Set

Commelina caroliniana Walter is an andromonoecious rainy-season weed. It bears staminate and hermaphrodite flowers in spathes. In some spathes, structurally hermaphrodite flowers of the third and fourth orders function either as male or female. The flowers are structured for cross-pollination. Events of floral biology suggest weak protandry which also contributes to cross-pollination. Large numbers of hymenopterans (nine species) visited the flowers and transferred pollen to stigmas. Whenever cross-pollination failed, selfing took over. Auto-fertility and self-compatibility indices revealed that the plants were self-compatible. Only some flowers of the third and fourth orders within a spathe were partially self-compatible. These facts notwithstanding, manual cross-pollination of flowers yields increased fruit and seed set.

Delayed autonomous selfing and inbreeding depression in the Australian annual Hibiscus trionum var. vesicarius (Malvaceae)

2006 ◽  
Vol 54 (1) ◽  
pp. 27 ◽  
Author(s):  
Leahwyn Seed ◽  
Glenda Vaughton ◽  
Mike Ramsey
Keyword(s):  
Inbreeding Depression ◽  
Pollen Germination ◽  
Seed Set ◽  
Pollen Grains ◽  
Reproductive Assurance ◽  
Selfed Progeny ◽  
Delayed Selfing ◽  
Hibiscus Trionum ◽  
Self Compatibility ◽  
Outcrossing Species

The Australian annual, Hibiscus trionum var. vesicarius, produces large, showy flowers typical of an outcrossing species, yet flowers autonomously self-pollinate. We used experimental pollinations to examine self-compatibility, inbreeding depression and the efficiency and mechanism of autonomous selfing. Seed set of self- or cross-pollinated flowers did not differ, indicating that plants were fully self-compatible. Seed set following autonomous selfing varied among plants, and was 11–103% of that following hand-selfing. Autonomous selfing was delayed, and styles curved and stigmas contacted the anthers before flowers closed. Delayed selfing was facultative and curvature depended on the number of pollen grains on stigmas, with 50 or more grains preventing curvature. Both self- and cross-pollen prevented curvature. Similarly to unpollinated styles, styles that were pollinated with dead pollen curved fully, indicating that either pollen germination or pollen-tube growth prevents curvature. Within flowers, the five styles acted independently, depending on the amount of pollination that each received. Although plants exhibit a high potential for selfing, crossed progeny outperformed selfed progeny and cumulative inbreeding depression was 0.64, which is high for a self-compatible annual. Despite this high inbreeding depression, delayed selfing would be advantageous under variable pollinator conditions, providing reproductive assurance.

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.

CORRELATED RESPONSE IN BROWN SARSON

1970 ◽  
Vol 12 (4) ◽  
pp. 905-913 ◽  
Author(s):  
T. Swamy Rao
Keyword(s):  
Gamma Irradiation ◽  
Seed Set ◽  
Previous History ◽  
The Self ◽  
Correlated Response ◽  
History Of ◽  
Self Compatibility ◽  
Selection For ◽  
Direction Opposite ◽  
Brown Sarson

The correlated response with changes in self-compatibility in three varieties of brown sarson subjected to gamma irradiation was examined. Selection for improved seed set in the irradiated populations showed that substantial correlated response can result for a constellation of other characters in which the self-compatible and self-incompatible forms differ. The correlated response was in a direction opposite to that of the previous history of selection.

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

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.

scholarly journals How does timing of flowering affect competition for pollinators, flower visitation and seed set in an early spring grassland plant?

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sandra Kehrberger ◽  
Andrea Holzschuh
Keyword(s):  
Species Interactions ◽  
Seed Set ◽  
Weather Conditions ◽  
Early Spring ◽  
Flowering Plants ◽  
Early Flowering ◽  
Flower Visitation ◽  
Floral Longevity ◽  
Visitation Rates ◽  
Phenological Shifts

Abstract Knowledge on how the timing of flowering is related to plant fitness and species interactions is crucial to understand consequences of phenological shifts as they occur under climate change. Early flowering plants may face advantages of low competition for pollinators and disadvantages of low pollinator abundances and unfavourable weather conditions. However, it is unknown how this trade-off changes over the season and how the timing affects reproductive success. On eight grasslands we recorded intra-seasonal changes in pollinators, co-flowering plants, weather conditions, flower visitation rates, floral longevity and seed set of Pulsatilla vulgaris. Although bee abundances and the number of pollinator-suitable hours were low at the beginning of the season, early flowers of P. vulgaris received higher flower visitation rates and estimated total number of bee visits than later flowers, which was positively related to seed set. Flower visitation rates decreased over time and with increasing number of co-flowering plants, which competed with P. vulgaris for pollinators. Low interspecific competition for pollinators seems to be a major driver for early flowering dates. Thus, non-synchronous temporal shifts of co-flowering plants as they may occur under climate warming can be expected to strongly affect plant-pollinator interactions and the fitness of the involved plants.

Breeding Systems of Disjunct Populations of Christmas Bells (Blandfordia grandiflora R.Br., Liliaceae): Variation in Self-Fertility and an Ovular Mechanism Regulating Self-Fertilisation

1993 ◽  
Vol 41 (1) ◽  
pp. 35 ◽  
Author(s):  
M Ramsey ◽  
N Prakash ◽  
S Cairns
Keyword(s):  
Seed Set ◽  
Pollen Tubes ◽  
Breeding Systems ◽  
Seed Abortion ◽  
Self Incompatibility ◽  
Coastal Plants ◽  
Hand Pollination ◽  
Disjunct Populations ◽  
Pollen Vectors ◽  
Blandfordia Grandiflora

The breeding systems of disjunct tableland and coastal populations of Christmas bells were determined using hand-pollination experiments. In both populations, 90% or more of self-pollinated plants produced seeds. Tableland plants were significantly more self-fertile than coastal plants (ratio of self seed set to cross seed set: tableland, 0.55 ± 0.03; coast, 0.08 ± 0.02). Significant variation among plants for self-fertility was found in both populations. Autofertility was 1.6% or less in both populations indicating that pollen vectors are necessary for seed set. Seed set by agamospermy in both populations was less than 0.1%. Percentage seed abortion was greater in self-pollinated plants than cross-pollinated plants in both populations. In both self- and cross-pollinated plants, seed abortion was twice as great in the coastal population than in the tableland population. No evidence was found for stigmatic or stylar self-incompatibility. Self and cross pollen adhered to and germinated equally well on stigmas in both populations (72 - 77% germination). Similarly, there were no differences between pollination treatments or populations in the percentage of ovules penetrated by pollen tubes (82 - 89% penetration). When self-pollination preceded cross-pollination by 24 h or longer seed set was significantly reduced compared to flowers that were cross-pollinated only, suggesting ovules were pre-empted by self pollen tubes. Collectively these results strongly suggest that self seed set was reduced by a mechanism operating at the ovule level, such as early-acting inbreeding depression due to recessive seed-aborting genes, although incomplete late-acting self-incompatibility cannot be ruled out. For coastal plants, this ovular mechanism largely prevents selfing, indicating plants were predominantly outcrossing although most produced some self seed. For tableland plants, substantial seed set by selfing may occur under natural conditions.

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