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.

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 Recent phylogeographic structure in a widespread ‘weedy’ Neotropical tree species,Cordia alliodora(Boraginaceae)

2012 ◽  
Vol 40 (4) ◽  
pp. 693-706 ◽  
Author(s):  
Paul D. Rymer ◽  
Christopher W. Dick ◽  
Giovanni G. Vendramin ◽  
Anna Buonamici ◽  
David Boshier
Keyword(s):  
Tree Species ◽  
Phylogeographic Structure ◽  
Cordia Alliodora ◽  
Neotropical Tree

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.

scholarly journals Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant–plant mutualism

2014 ◽  
Vol 281 (1785) ◽  
pp. 20140474 ◽  
Author(s):  
Elizabeth G. Pringle
Keyword(s):  
Seed Predation ◽  
Reproductive Output ◽  
Plant Reproduction ◽  
Scale Insects ◽  
Cordia Alliodora ◽  
Ant Colonies ◽  
Previous Generation ◽  
Neotropical Tree ◽  
Tree Fruits ◽  
Bruchid Beetles

In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant–plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.

scholarly journals To be, or not to be a Stelis

Lankesteriana ◽  
2019 ◽  
Author(s):  
Adam P. Karremans
Keyword(s):  
Key Words ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Floral Morphology ◽  
Recent Common Ancestor ◽  
Multiple Sources ◽  
Infrageneric Classification ◽  
Species Groups ◽  
Convergence And Divergence ◽  
Close Relatives

Despite the availability of multiple sources of evidence and consistency in the support for a broadly circumscribed Stelis Sw. (Orchidaceae: Pleurothallidinae), some authors continue to be hesitant in its use. It is certain that the more typical species of Stelis, with their triangular, flattish flowers with very short fleshy petals and lip, form a monophyletic group that is easily recognized. However, it is likewise undisputed that they are not an isolated lineage in the subtribe and that several groups of species with a similar vegetative habit but that lack the typical Stelis flower are in fact very close relatives, sharing a relatively recent common ancestor. Those species groups need to be classified in a way that also reflects their own evolutionary history, and alternatives to a broadly circumscribed Stelis are possible yet neither straightforward or practical at this time. An infrageneric classification for the whole group is provided here in an attempt to clarify which species actually belong where in this highly complex affinity. Emphasis is made on the difficulty of diagnosing the less typical members of each proposed subgenus or section, and on the importance of floral convergence and divergence as a result of pollinator adaptation. As here defined, Stelis is the largest genus in the Pleurothallidinae, with 1243 species. Key words: convergence; evolutionary history; floral morphology; generic circumscription; Pleurothallidinae; pollinator adaptation

Reproductive success and variation in floral traits in the Iberian Peninsula endemic white campion Silene marizii (Caryophyllaceae)

Biologia ◽  
2009 ◽  
Vol 64 (2) ◽  
Author(s):  
Mónica García-Barriuso ◽  
Eva Ávila ◽  
M. Sánchez-Anta ◽  
Antonio Crespí ◽  
Sonia Bernardos ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Iberian Peninsula ◽  
Seed Production ◽  
Fruit Set ◽  
Floral Morphology ◽  
Floral Traits ◽  
Morphometric Traits ◽  
The West ◽  
Peduncle Length ◽  
Number Of Seeds

AbstractSilene marizii (Caryophyllaceae) is a schizoendemism of the west Iberian Peninsula. The correlation between the evolution of reproductive success (as measured in terms of fruit set and seed production) and five floral traits (peduncle length, calyx length, calyx width, petal limb length, and petal limb width) was investigated in five populations of S. marizii, taking into account both intra-populational and inter-populational variability. The populations studied represented the different habitats of S. marizii over its area of distribution. None of the five traits examined was significantly and positively correlated with the number of seeds produced by the flower. An analysis was also made of how floral morphology varies with the position of the flower in the inflorescence in the five populations. The populations from higher altitudes (Caramulhino, Puerto de Menga and Peña de la Cruz) had larger peduncles, calices and petal limbs than those living at lower altitudes (Sabugal and Mangualde) All five morphometric traits, plus the number of ovules per ovary, varied significantly between flower positions on the same plant and among populations.

Floral Morphology, Biology and Sex Allocation in Disjunct Populations of Christmas Bells (Blandfordia grandiflora, Liliaceae) With Different Breeding Systems

1993 ◽  
Vol 41 (6) ◽  
pp. 749 ◽  
Author(s):  
M Ramsey
Keyword(s):  
Biomass Allocation ◽  
Sex Allocation ◽  
Floral Morphology ◽  
Breeding Systems ◽  
Floral Traits ◽  
Pollen Production ◽  
Nectar Production ◽  
Pollinator Attraction ◽  
Coastal Plants ◽  
Blandfordia Grandiflora

Evolutionary shifts in breeding systems are often accompanied by changes in reproductive attributes such as floral morphology and biology, and pre- and post-zygotic allocation patterns. The effects of breeding system variation on several such attributes were examined in self-fertile tableland and outcrossing coastal populations of Blandfordia grandiflora R. Br. In general, overall flower size was similar in both populations, although pedicel and pistil stipe diameters were greater in coastal plants, and pistil length and stigma-anther separation were greater in tableland plants. Although all floral parts from coastal flowers weighed more, proportional biomass allocation to floral parts was similar in both populations. Daily nectar production per flower was similar in both populations. Tableland flowers produced more ovules but fewer pollen grains than did coastal flowers. Pollen-ovule ratios were 11 500 in coastal flowers and 5600 in tableland flowers. Open-pollinated tableland fruits produced more seeds than coastal fruits, but individual seeds weighed less; total seed biomass of tableland fruits was greater than coastal fruits. Prezygotic relative male biomass did not differ significantly between populations. Relative male biomass, estimated from stamen and seed weights, was 5% greater in coastal plants, although populations did not differ significantly. Similarly, relative biomass allocation to pollinator attraction (i.e. coralla and nectar) did not differ between populations. The onset and duration of stigmatic receptivity and pollen longevity of flowers from the two populations were similar. The large differences in ovule, seed and pollen production supports sex allocation theory which predicts that in self-fertile plants resource allocation should be female biased whereas in outcrossing plants, allocation should be male biased. The lack of differences between the Christmas bell populations in other aspects of floral morphology, allocation pattterns and biology suggests that changes in ovule and pollen production precedes changes in other traits during the evolution of autonomous selfing. Overall, these findings suggest that tableland plants may have evolved self-fertility only recently and selection has had insufficient time to change floral traits. Alternatively, self-fertility may not have evolved recently and floral traits promoting outcrossing have been maintained by selection, imposed by inbreeding depression and/or overdominance.

Variation in acid phosphatase activity among progeny from controlled crosses in the ectomycorrhizal fungus Laccaria bicolor

1990 ◽  
Vol 68 (4) ◽  
pp. 864-866 ◽  
Author(s):  
Bradley R. Kropp
Keyword(s):  
Acid Phosphatase ◽  
Key Words ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Ectomycorrhizal Fungus ◽  
The Other ◽  
Laccaria Bicolor ◽  
Polygenic Inheritance ◽  
Controlled Crosses

The variation in acid phosphatase activity among the monokaryotic F1 progeny from two different synthesized dikaryotic cultures of the ectomycorrhizal basidiomycete Laccaria bicolor was examined. The progeny of one of the dikaryons showed variation in acid phosphatase activity up to 10 times that of the lowest value. The progeny of the other dikaryon were much less variable, showing differences of up to 5 times the lowest value. Both sets of monokaryotic progeny showed distributions indicative of polygenic inheritance for acid phosphatase activity in this fungus. Key words: ectomycorrhizae, genetics, monokaryon, acid phosphatase, Laccaria bicolor.

Reproductive biology of island and mainland populations of Primula mistassinica (Primulaceae) on Lake Huron shorelines

1998 ◽  
Vol 76 (11) ◽  
pp. 1819-1827 ◽  
Author(s):  
Brendon MH Larson ◽  
Spencer CH Barrett
Keyword(s):  
Reproductive Biology ◽  
Floral Morphology ◽  
Ecological Factors ◽  
Reproductive Traits ◽  
Lake Huron ◽  
Geographic Scale ◽  
Seed Fertility ◽  
Island Populations ◽  
Incompatibility System ◽  
Morph Ratios

To investigate the influence of insularity on plant reproductive biology at a local geographic scale, we examined aspects of reproduction in distylous Primula mistassinica Michx. (Primulaceae) on Lake Huron shorelines of the Bruce Peninsula and adjacent Tobermory Islands in Ontario, Canada. A total of 7 mainland and 13 nearshore island populations were compared. Controlled pollinations demonstrated that P. mistassinica possesses a dimorphic incompatibility system with intermorph crosses setting significantly more seeds than self or intramorph crosses. Floral morphology, population style-morph ratios, and seed fertility were compared in mainland and nearshore island populations to determine whether there was evidence for differences in reproductive traits between these areas. Style-morph ratios did not differ significantly from equilibrium expectations, and there were no consistent differences between island and mainland populations in floral morphology or fertility. Rather, the generalized pollination system of P. mistassinica and extensive historical opportunities for colonization appear to have mitigated insular effects so that proximate ecological factors are more relevant to the current reproductive biology of populations.Key words: distyly, insularity, pollination, reproductive biology.

Development and selection for apomixis in cassava, Manihot esculenta Crantz

1994 ◽  
Vol 74 (4) ◽  
pp. 857-858 ◽  
Author(s):  
Nagib M. A. Nassar
Keyword(s):  
Key Words ◽  
Interspecific Hybridization ◽  
Wild Species ◽  
Manihot Esculenta ◽  
Cytogenetic Analysis ◽  
Marker Gene ◽  
Morphological Characteristics ◽  
Manihot Esculenta Crantz ◽  
Selection For ◽  
Controlled Crosses

Apomixis provides fixation of heterosis and avoids contamination of seedlings by diseases. Observations on offspring uniformity for selected morphological characteristics and use of a marker gene in controlled crosses produced facultative apomictic lines in cassava. Cytogenetic analysis showed apomixis occurrence to be associated with aneuploidy and interspecific hybridization. Key words: Wild species, aneuploidy, interspecific hybridization

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