scholarly journals Correlación morfo-específica en flores de Palicourea padifolia (Rubiaceae)

2017 ◽  
pp. 35 ◽  
Author(s):  
Angélica Hernández ◽  
Juan Francisco Ornelas
Keyword(s):  
Relative Position ◽  
Morphological Traits ◽  
Floral Morphology ◽  
Pollen Flow ◽  
Floral Traits ◽  
Selective Pressures ◽  
Corolla Length

Distyly is a floral polymorphism in which about half of the plants in a population have long styles and short stamens (Pin), whereas the remainder possess short styles and long stamens (Thrum). It has been suggested that the relative position of anthers and stigmas in distylous flowers enhances pollen flow between flowers of opposite morphs (legitimate pollination), in comparison to pollen flow between flowers of the same morph (illegitimate pollination). We studied the floral morphology of both floral morphs (six variables) in Palicourea padifolia (Rubiaceae) and found significant differences between floral morphs in floral traits that define the floral polymorphism. However, the correlations between morphological traits that define the floral morphs (morph-specific), and the significant correlations were stronger in the short styled morph. The morph-specific correlation patterns among some of the floral traits suggest differential selective pressures between floral morphs, regardless of corolla length.

scholarly journals Bee-Mediated Selection Favors Floral Sex Specialization in a Heterantherous Species: Strategies to Solve the Pollen Dilemma

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1685
Author(s):  
Larissa C. Oliveira ◽  
Alberto L. Teixido ◽  
Renata Trevizan ◽  
Vinícius L. G. Brito
Keyword(s):  
Floral Morphology ◽  
Pollen Dispersal ◽  
Fitness Components ◽  
Selection Gradients ◽  
Selective Pressures ◽  
Pollen Removal ◽  
Broad Variation ◽  
Phenotypic Gender ◽  
Pollen Flowers ◽  
Two Populations

Animal-pollinated plants show a broad variation in floral morphology traits and gametophyte production within populations. Thus, floral traits related to plant reproduction and sexuality are usually exposed to pollinator-mediated selection. Such selective pressures may be even stronger in heterantherous and pollen flowers, in which pollen contributes to both bee feeding and pollination, overcoming the “pollen dilemma” or the inability to perform both functions simultaneously. We describe the phenotypic gender and sexual organ morphology of flowers in two populations of Macairea radula (Melastomataceae), a heterantherous and buzz-pollinated species with pollen flowers. We estimated selection gradients on these traits through female and male fitness components. Both populations showed sizeable phenotypic gender variation, from strict hermaphrodites to increased femaleness or maleness. We found a continuous variation in style and stamen size, and this variation was correlated with corresponding shape values of both sexual organs. We detected bee-mediated selection towards short and long styles through seed number and towards intermediate degrees of heteranthery through pollen removal in one population, and selection towards increased maleness through pollen dispersal in both populations. Our results suggest that bee-mediated selection favors floral sex specialization and stylar dimorphism in M. radula, optimizing reproductive success and solving the pollen dilemma.

Incompatibility in Cordia alliodora (Boraginaceae), a neotropical tree

1995 ◽  
Vol 73 (3) ◽  
pp. 445-456 ◽  
Author(s):  
D. H. Boshier
Keyword(s):  
Key Words ◽  
Floral Morphology ◽  
Floral Traits ◽  
Cordia Alliodora ◽  
Evolution And Development ◽  
Neotropical Tree ◽  
Ultraviolet Microscopy ◽  
Incompatibility System ◽  
Controlled Crosses

Incompatibility and variation in floral morphology in Cordia alliodora (R. & P.) Oken (Boraginaceae) were investigated using a combination of fieldwork and light and ultraviolet microscopy. Results from controlled crosses clearly showed the presence of two groups of trees, where intergroup crosses were compatible but intragroup crosses were incompatible. A sporophytic, diallelic, one-locus incompatibility system was inferred. Limited failure of the incompatibility mechanism was found (approximately 1% of crosses) for both selfs and intragroup crosses. Whereas most authors previously described C. alliodora as a homostyle, measurement of floral traits and study of their relationship to controlled crosses revealed a poorly defined variation in stigma size strongly associated with the incompatibility groups. The relatively undeveloped heteromorphy, coupled with a strong incompatibility mechanism, is of particular interest. The genus Cordia, in particular the Cerdanae, appears to offer fruitful ground for further investigation into aspects of the evolution and development of heterostyly. Key words: incompatibility, heterostyly, Cordia alliodora.

Breeding system in an alpine species: Rhododendron ferrugineum L. (Ericaceae) in the French northern Alps

1997 ◽  
Vol 75 (5) ◽  
pp. 736-743 ◽  
Author(s):  
Nathalie Escaravage ◽  
André Pornon ◽  
Bernard Doche ◽  
Irene Till-Bottraud
Keyword(s):  
Breeding System ◽  
Floral Morphology ◽  
Floral Traits ◽  
Anther Dehiscence ◽  
Selfing Rate ◽  
Stigma Receptivity ◽  
Fertility Index ◽  
Rhododendron Ferrugineum ◽  
Self Compatibility ◽  
Alpine Shrub

The breeding system of the alpine shrub Rhododendron ferrugineum was studied at two sites of a population (site L and site H) in the French Alps. The aims were to estimate the degree of selling and (or) outcrossing and to determine if floral traits (including floral morphology, pollen to ovule ratio, stigma receptivity) may be related to the breeding system of the shrub. First, floral traits (corolla length and anther, and style heights) were measured, the number of pollen tetrads and ovules were counted, and the date of stigma receptivity and anther dehiscence were recorded. Second, five pollinations treatments (unmanipulated flowers, natural selfing, hand selfing, natural outcrossing, and hand outcrossing) were performed on 35 randomly chosen individuals in each site, and after each treatment the number of seeds per fruit was recorded. The results demonstrate that Rhododendron ferrugineum is self-compatible (self-compatibility index = 0.95 and 0.97; auto-fertility index = 0.92 and 0.98; selfing rate = 0.24 and 0.11 at sites L and H, respectively). Indices values are not significantly different between the two sites and facultatively xenogamous (pollen to ovule ratio = 669.5 ± 280.5 and 845.2 ± 246.9 at sites L and H, respectively). Key words: breeding system, Rhododendron ferrugineum, floral morphology, phenology, P:O ratio.

Inheritance and breeding significance of two floral morphological traits in cowpea (Vigna unguiculata)

1989 ◽  
Vol 112 (1) ◽  
pp. 137-138 ◽  
Author(s):  
L. C. Emebiri
Keyword(s):  
Vigna Unguiculata ◽  
Morphological Traits ◽  
Floral Morphology ◽  
Flower Size ◽  
Wide Crosses ◽  
Unconscious Selection ◽  
Breeding Work ◽  
Hand Pollination ◽  
Seed Characteristics ◽  
Selection Of

Variations in floral morphology have been observed by most breeders involved in cowpea (Vigna unguiculata (L.) Walpers) improvement. Usually, the most successful pod set is achieved following hand pollination when plants with large flowers are used as female parents because these are easy to manipulate. In breeding work involving wide crosses, unconscious selection of female parents on the basis of flower size could lead to correlated changes in pod and seed characteristics which may or may not be desirable. This would depend on the heritability of flower size and its correlation with the pod and seed characteristics.

scholarly journals Bumblebee Behavior on Flowers, but Not Initial Attraction, Is Altered by Short-Term Drought Stress

2021 ◽  
Vol 11 ◽  
Author(s):  
Rebecca J. Höfer ◽  
Manfred Ayasse ◽  
Jonas Kuppler
Keyword(s):  
Morphological Traits ◽  
Floral Scent ◽  
Water Levels ◽  
Floral Traits ◽  
Short Term ◽  
Floral Trait ◽  
Visitation Rate ◽  
Flower Visitor ◽  
Visitor Behavior ◽  
Flower Visitation

Climate change is leading to increasing drought and higher temperatures, both of which reduce soil water levels and consequently water availability for plants. This reduction often induces physiological stress in plants, which in turn can affect floral development and production inducing phenotypic alterations in flowers. Because flower visitors notice and respond to small differences in floral phenotypes, changes in trait expression can alter trait-mediated flower visitor behavior. Temperature is also known to affect floral scent emission and foraging behavior and, therefore, might modulate trait-mediated flower visitor behavior. However, the link between changes in flower visitor behavior and floral traits in the context of increasing drought and temperature is still not fully understood. In a wind-tunnel experiment, we tested the behavior of 66 Bombus terrestris individuals in response to watered and drought-stressed Sinapis arvensis plants and determined whether these responses were modulated by air temperature. Further, we explored whether floral traits and drought treatment were correlated with bumblebee behavior. The initial attractiveness of drought and watered plants did not differ, as the time to first visit was similar. However, bumblebees visited watered plants more often, their visitation rate to flowers was higher on watered plants, and bumblebees stayed for longer, indicating that watered plants were more attractive for foraging. Bumblebee behavior differed between floral trait expressions, mostly independently of treatment, with larger inflorescences and flowers leading to a decrease in the time until the first flower visit and an increase in the number of visits and the flower visitation rate. Temperature modulated bumblebee activity, which was highest at 25°C; the interaction of drought/water treatment and temperature led to higher visitation rate on watered plants at 20°C, possibly as a result of higher nectar production. Thus, bumblebee behavior is influenced by the watered status of plants, and bumblebees can recognize differences in intraspecific phenotypes involving morphological traits and scent emission, despite overall morphological traits and scent emission not being clearly separated between treatments. Our results indicate that plants are able to buffer floral trait expressions against short-term drought events, potentially to maintain pollinator attraction.

scholarly journals Inflorescence and floral traits of the Colombian species of Tristerix (Loranthaceae) related to hummingbird pollination

2017 ◽  
Vol 74 (2) ◽  
pp. 061 ◽  
Author(s):  
Favio González ◽  
Natalia Pabón-Mora
Keyword(s):  
Morphological Traits ◽  
Sister Group ◽  
Floral Traits ◽  
The Andes ◽  
Hummingbird Pollination ◽  
Floral Diversification ◽  
Successive Initiation ◽  
Group Relationships

Floral diversification in Loranthaceae reaches its highest peak in the Andes. The flowers of the exclusively Andean genus Tristerix exhibit tubular and vividly coloured flowers pollinated by hummingbirds. We studied inflorescence and flower morphoanatomy of the two Colombian species, T. longebracteatus and the highly endangered T. secundus. Both species have terminal racemes with up to 26 ebracteolate flowers, of which the proximal one opens and sets fruits first. The slightly irregular calyx initiation is followed by the simultaneous initiation of petals and the successive initiation of stamens. Anthesis is fenestrate, explosive, and triggered by the tension of the style against the abaxial petals, a mode so far not reported in Loranthaceae. Anthetic petals spread symmetrically in T. longebracteatus and asymmetrically in T. secundus. Nectar is produced by a supraovarial disk and by the petal mesophyll. Floral lifespan lasts up to 20 days. The hummingbirds Eriocnemis vestita and Pterophanes cyanopterus are the likely pollinators of T. secundus. Morphological traits are inconclusive to support one of the two competing sister group relationships that involve Tristerix, as the lack of cataphylls in renewal shoots links Ligaria and Tristerix, whereas the terminal inflorescences support its relationship with Desmaria and Tupeia.

Patterns of pollen flow in monomorphic enantiostylous species: the importance of floral morphology and pollinators’ size

2020 ◽  
Vol 306 (2) ◽  
Author(s):  
Joicy M. Morais ◽  
Hélder N. Consolaro ◽  
Leonardo L. Bergamini ◽  
Victoria Ferrero
Keyword(s):  
Floral Morphology ◽  
Pollen Flow

scholarly journals Genetic parameters of two bc2f1 populations for development of superior male sterile lines pertaining to morpho-floral traits for aerobic rice (Oryza sativa L.)

2016 ◽  
Vol 13 (2) ◽  
pp. 198-213
Author(s):  
P Raghavendra ◽  
S Hittalmani
Keyword(s):  
Morphological Traits ◽  
Genetic Parameters ◽  
Oryza Sativa L ◽  
Tiller Number ◽  
Superior Performance ◽  
Floral Traits ◽  
Aerobic Rice ◽  
Male Sterile ◽  
Backcross Populations ◽  
High Heritability

The behaviour of introgressed male-sterilility with respect to various morphological traits is based on its superior performance in segregating backcross populations. In this study a maiden attempt has been made to identify male sterile lines suitable for developing aerobic rice hybrids. Two BC2F1 populations derived from IR70369A x MAS 99 and KCMS31A x MAS 99 crosses were evaluated for various morpho-floral traits. Pollen and spikelet fertility test revealed that all plants of these populations were completely male sterile. Genetic variability studies indicated high heritability for most of the traits (>60%). Narrow variation between Phenotypic Co-efficient of variation (PCV) and Genotypic Coefficient of Variation (GCV) was observed for most traits. Stigma exertion, Panicle exertion, Tiller number and Spikelet per panicle recorded moderate heritability with wider differenced between PCV and GCV. Negatively skewed platykurtic distribution was observed for most of the traits in both BC2F1 populations. The identified new male sterile lines will be stabilised, and they could serve as potential A lines for development of rice hybrids for aerobic condions.SAARC J. Agri., 13(2): 198-213 (2015)

scholarly journals Phenotypic integration in style dimorphic daffodils ( Narcissus , Amaryllidaceae) with different pollinators

2014 ◽  
Vol 369 (1649) ◽  
pp. 20130258 ◽  
Author(s):  
Rocío Pérez-Barrales ◽  
Violeta I. Simón-Porcar ◽  
Rocío Santos-Gally ◽  
Juan Arroyo
Keyword(s):  
Genetic Diversity ◽  
Population Genetic ◽  
Genetic Parameters ◽  
Floral Traits ◽  
Phenotypic Integration ◽  
Selective Pressures ◽  
Population Genetic Parameters ◽  
Dimorphic Species ◽  
Close Fit

Different pollinators can exert different selective pressures on floral traits, depending on how they fit with flowers, which should be reflected in the patterns of variation and covariation of traits. Surprisingly, empirical evidence in support of this view is scarce. Here, we have studied whether the variation observed in floral phenotypic integration and covariation of traits in Narcissus species is associated with different groups of pollinators. Phenotypic integration was studied in two style dimorphic species, both with dimorphic populations mostly visited by long-tongued pollinators (close fit with flowers), and monomorphic populations visited by short-tongued insects (loose fit). For N. papyraceus , the patterns of variation and correlation among traits involved in different functions (attraction and fit with pollinators, transfer of pollen) were compared within and between population types. The genetic diversity of populations was also studied to control for possible effects on phenotypic variation. In both species, populations with long-tongued pollinators displayed greater phenotypic integration than those with short-tongued pollinators. Also, the correlations among traits involved in the same function were stronger than across functions. Furthermore, traits involved in the transfer of pollen were consistently more correlated and less variable than traits involved in the attraction of insects, and these differences were larger in dimorphic than monomorphic populations. In addition, population genetic parameters did not correlate with phenotypic integration or variation. Altogether, our results support current views of the role of pollinators in the evolution of floral integration.

Sign in / Sign up

Export Citation Format

Share Document