scholarly journals Autonomous pollination alleviates pollen limitation in the endemic Cienfuegosia yucatanensis Millsp. (Malvaceae)

2020 ◽  
Vol 99 (1) ◽  
pp. 80-91
Author(s):  
Víctor Parra-Tabla ◽  
Conchita Alonso
Keyword(s):  
Seed Production ◽  
Inbreeding Depression ◽  
Seed Weight ◽  
Pollen Limitation ◽  
Pollen Tubes ◽  
Pollen Deposition ◽  
Cross Pollination ◽  
The North ◽  
Hand Pollination ◽  
Self Compatibility

Background: Self-compatibility is common on endemic plant species, but pollen limitation and self-pollination could be risk factors. Study species: The endemic Cienfuegosia yucatanensis (Malvaceae), whose distribution is mainly restricted to the north coast of the peninsula of Yucatán, México. Questions: a) Are flowers of C. yucatanensis autonomous for pollination? b) Are C. yucatanensis fruit or seed-set limited by pollen deposition? and, c) Is there evidence of early inbreeding depression in C. yucatanensis? Study sites and dates: Two sites in the north of the peninsula of Yucatán in a seasonally dry scrubland, in the rainy season of 2013 and 2014. Methods: Number of flowers and fruits were weekly recorded. Flowers were collected to count the number of conspecific pollen load and the number of pollen tubes. Autonomous pollination and pollen limitation were evaluated with a hand-pollination experiment. Inbreeding depression on fruit and seed production, and seed weight was evaluated. Results: Flower and fruit production occur simultaneously and last from August to October. Conspecific pollen deposition on stigmas occurred through the whole flowering season and a maximum of pollen tubes was observed in August. Autonomous pollination treatment lead to similar fruit and seed production than cross-pollination, but open pollination produced significantly more seeds. No significant differences among self- and cross-pollination treatments on fruit and seed production or seed weight, were found.  Conclusions: Our results suggest that self-compatibility combined with a relatively efficient autonomous pollination, are suitable mechanisms for the reproductive assurance in C. yucatanensis, with no apparent effects of early inbreeding depression.

scholarly journals Breeding system and inbreeding depression in the rare orchid, Platanthera praeclara, in a fragmented grassland landscape

Botany ◽  
2018 ◽  
Vol 96 (3) ◽  
pp. 151-159 ◽  
Author(s):  
Steven E. Travers ◽  
Kirk Anderson ◽  
Pati Vitt ◽  
Marion O. Harris
Keyword(s):  
Inbreeding Depression ◽  
Seed Quality ◽  
Detectable Effect ◽  
Plant Fitness ◽  
Cross Pollination ◽  
Self Pollination ◽  
Capsule Production ◽  
Hand Pollination ◽  
Platanthera Praeclara ◽  
Self Compatibility

An important consequence of self-compatibility in plants is that self-pollination can have deleterious effects on plant fitness because of inbreeding. We conducted a hand pollination experiment under field conditions to measure the magnitude of inbreeding depression associated with self-pollination in the rare western prairie fringed-orchid Platanthera praeclara Sheviak and Bowles. By comparing capsules and seeds resulting from cross versus self-pollination treatments, we determined that self-pollination reduces seed quality while having no detectable effect on capsule production or seed numbers. A smaller percentage of seeds resulting from self-pollination contained an embryo (18%) relative to seeds from cross-pollination (46%). Seeds that had an embryo were scored for the size of the embryo, small or large. A smaller proportion of seeds from self-pollination contained a large embryo (75%) relative to seeds from cross-pollination (92%). These results suggest that sexual reproduction and recruitment in this rare plant are dependent on the frequency of pollinator visitations that result in outcrossing.

Limitations on reproduction in alpine Ranunculus acris

1997 ◽  
Vol 75 (1) ◽  
pp. 137-144 ◽  
Author(s):  
Ørjan Totland
Keyword(s):  
Seed Production ◽  
Resource Availability ◽  
Seed Weight ◽  
Pollen Limitation ◽  
Resource Limitation ◽  
Limiting Factors ◽  
Perennial Herb ◽  
Plant Variation ◽  
Hand Pollination ◽  
Ranunculus Acris

This study examines experimentally the influence of limiting factors on seed to ovule ratio and seed weight in three alpine populations of the perennial herb Ranunculus acris L. at Finse, southwest Norway. To test for pollen and resource limitation, seed production of supplementally pollinated or completely defoliated plants was compared to that of untreated plants. In one population the experiment was repeated twice during the season. In mid-season, supplemental hand-pollination had no significant effect on seed to ovule ratio, but significantly increased the seed weight, whereas complete defoliation resulted in a significant decrease in seed to ovule ratio and a marginally significant decrease in seed weight. These results indicate that pollen limitation occurred on seed weight and resource limitation mainly on seed to ovule ratio. Seed production in late-flowering control and defoliated plants in one population was nearly completely absent, whereas supplemental pollination increased seed production substantially. Most seeds were produced at the lowest elevation, and frost damage on developing seeds was most pronounced at the highest elevation population, suggesting that severe weather conditions at the highest altitudes had a negative influence on reproductive processes. Significant positive relationships between seed number and seed weight were found, possibly reflecting a large among-plant variation in total resource availability. Key words: altitude gradient, climate, defoliation, pollen and resource availability, seasonal variation, seed size.

scholarly journals Pollination of two species of Vellozia (Velloziaceae) from high-altitude quartzitic grasslands, Brazil

2007 ◽  
Vol 21 (2) ◽  
pp. 325-333 ◽  
Author(s):  
Claudia Maria Jacobi ◽  
Mário César Laboissiérè del Sarto
Keyword(s):  
High Altitude ◽  
Pollen Limitation ◽  
Cross Pollination ◽  
Se Brazil ◽  
Self Compatibility ◽  
Leaf Cutting ◽  
Pollen Theft ◽  
Floral Displays ◽  
Facultative Xenogamy ◽  
And Control

The pollinators and breeding system of two species of Vellozia (Velloziaceae) from high-altitude quartzitic grasslands in SE Brazil were studied. Vellozia leptopetala is shrubby and grows solely on rocky outcrops, V. epidendroides is herbaceous and grows on stony soils. Both bear solitary, hermaphrodite flowers, and have massive, short-lasting annual blooms. We evaluated the level of self-compatibility and need for pollinators of 50 plants of each species and 20-60 flowers per treatment: hand self- and cross-pollination, spontaneous pollination, agamospermy and control. The behavior of floral visitors on flowers and within plants was recorded. Both species are mostly self-incompatible, but produce a small number of seeds by self-fertilization. The pollen-ovule ratio suggests facultative xenogamy. They were visited primarily by bees, of which the most important pollinators were two leaf-cutting bees (Megachile spp.). Vellozia leptopetala was also pollinated by a territorial hummingbird. Low natural seed production compared to cross-pollination seed numbers suggests that pollen limitation is the main cause of low seed set. This was attributed to the combined effect of five mechanisms: selfing prior to anthesis, enhanced geitonogamy as a result of large floral displays, low number of visits per flower for the same reason, pollen theft by many insect species, and, in V. leptopetala, delivery of mixed pollen loads on the stigma as a consequence of hummingbird promiscuity.

scholarly journals DETERMINATION OF THE POLLEN PARENT AND ITS EFFECT ON LYCHEE FRUIT CHARACTERISTICS BY ISOZYMIC ANALYSIS.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 624e-625
Author(s):  
Chemda Degani ◽  
Ruth El-Batsri ◽  
Raphael A. Stern ◽  
Shmuel Gazit
Keyword(s):  
Inbreeding Depression ◽  
Seed Weight ◽  
Phosphoglucose Isomerase ◽  
Pollen Parent ◽  
Fruit Characteristics ◽  
Litchi Chinensis ◽  
Cross Pollination ◽  
Unequivocal Identification ◽  
Isozyme System

Fruits produced in two commercial lychee (litchi chinensis Sonn.) orchards consisting of adjacent blocks of `Floridian' and `Mauritius' were analyzed for pollen parentage by phosphoglucose isomerase (PGI) isozyme system. 'Mauritius' and `Floridian' were found to possess distinguishable homozygous isozyme phenotypes in PGI, thus allowing the unequivocal identification of their progenies as originating from self- or cross-pollination. The rates of hybrids produced in the two orchards were 69% and 87% for `Floridian' and 17% and 65% for `Mauritius'. In both cvs a significant correlation was found between pollen parent and the weights of fruits and seeds. Fruits originating from cross-pollination were heavier and contained heavier seeds than selfed fruits. The most pronounced effect of the pollen parent on seed weight was found in `Floridian, which appears to exhibit inbreeding depression.

Mating system of Calluna vulgaris: self-sterility and outcrossing estimations

1998 ◽  
Vol 76 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Grégory Mahy ◽  
Anne-Laure Jacquemart
Keyword(s):  
Mating System ◽  
Inbreeding Depression ◽  
Calluna Vulgaris ◽  
Pollen Tubes ◽  
Outcrossing Rate ◽  
Evolutionary Significance ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Cross Pollination ◽  
Mating System Evolution

The evolutionary significance of a mixed mating system is currently under debate. Calluna vulgaris (L). Hull, a widespread European shrub, is likely to undergo mixed mating because of geitonogamy. Mating system was investigated in three populations of C. vulgaris by means of greenhouse controlled crosses, pollen tube observations, and outcrossing rate estimations from allozyme markers. The species is highly self-sterile, most probably as a result of early inbreeding depression. Mean fruit set and mean seed number per fruit following hand self-pollination were 48 and 13%, respectively, of those following cross-pollination. Pollen tubes produced by self pollen penetrated the ovary with the same success as those from cross-pollination. Multilocus estimates of the outcrossing rates ranged from 0.71 to 0.90, and two estimates were significantly different from 1.00. Calluna vulgaris could thus be classified as being mixed mating with predominant allogamy. Single-locus estimates did not differ significantly from multilocus estimates suggesting that biparental inbreeding did not contribute to the apparent selfing rate. The maintenance of high early inbreeding depression despite an intermediate level of selfing is discussed with respect to recent theories on mating system evolution. Key words: Calluna vulgaris, mating system, self-sterility, pollen tubes, outcrossing rate, inbreeding depression.

scholarly journals Comparison of Self- and Cross-pollination on Pollen Tube Growth, Seed Development, and Germination in Crapemyrtle

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 575-578 ◽  
Author(s):  
Cecil Pounders ◽  
Sandra Reed ◽  
Margaret Pooler
Keyword(s):  
Seed Germination ◽  
Pollen Tube ◽  
Seed Production ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Cross Pollination ◽  
Landscape Plants ◽  
Incompatibility System ◽  
Self Fertilization ◽  
Self Compatibility

Crapemyrtle (L. indica and L. indica × L. fauriei hybrids) is one of the most popular flowering landscape plants in the U.S. Although many cultivars have been developed through breeding efforts, little has been published on the reproductive biology of the genus. The objective of this study was to evaluate barriers to successful self-seed production in crapemyrtle. Self-compatibility was assessed by comparing pollen tube growth, fruit and seed production, and seed germination following controlled self- and cross-pollinations. Observations of pollen tube growth at intervals up to 24 hours after self- and cross-pollination indicated no barriers to self-fertilization acting at the stigmatic or stylar level in L. indica, L. fauriei or cultivars derived from inter-specific hybrids of these two species. Self-pollinations of `Catawba', `Whit IV', `Tonto' and `Tuscarora' had lower percent seed pod set and seed germination than did cross-pollinations of these cultivars. The number of seeds per pod was lower when `Catawba', `Whit IV' and `Tuscarora' were self-rather than cross-pollinated, but no difference between `Tonto' self- and cross-pollinations was observed. When decreased pod set is combined with much lower seed germination for self-pollinations, selfing of crapemyrtle is extremely unproductive when compared to cross-pollination. A late-acting self-incompatibility system or inbreeding depression is indicated for L. indica and inter-specific crosses with L. fauriei.

Late-acting self-incompatibility in tea plant (Camellia sinensis)

Biologia ◽  
2012 ◽  
Vol 67 (2) ◽  
Author(s):  
Xuan Chen ◽  
Shan Hao ◽  
Li Wang ◽  
Wanping Fang ◽  
Yuhua Wang ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Camellia Sinensis ◽  
Pollen Tubes ◽  
Tea Plant ◽  
The Self ◽  
Self Incompatibility ◽  
Cross Pollination ◽  
Self Pollination ◽  
Hand Pollination ◽  
Pollen Tube Elongation

AbstractThe self-incompatibility of tea plant (Camellia sinensis (L.) O. Kuntze) was studied with the methods of aniline blue fluorescence assay and paraffin sections. The characteristics of pollen tube elongation after hand pollination was analyzed in 4 tea cultivars, including ‘Keemenzhong’, ‘Longjing-changye’, ‘Fuding-dabaicha’ and ‘Yabukita’, under self-pollination and cross-pollination, respectively. Although there were some difference among cultivars, pollen tubes elongated through the style and reach the ovary successfully at 48 h after pollination for both cross- and self-pollen tubes in all the four cultivars of tea. Pollen tubes entered into the ovule micropyles, however, only for cross-pollination, but not for self-pollination. Pollen tubes of selfing plants, failed in fertilizing, seemed have some difficulties to enter the ovule. All of which indicated that the self-incompatibility of tea plant is a late-acting self-incompatibility system (LSI) or an ovarian sterility (OS), in which the self incompatibility was due to none self pollen tube penetrating into the ovule and no fertilization.

Preferential outcrossing in Banksia ilicifolia (Proteaceae)

2005 ◽  
Vol 53 (2) ◽  
pp. 163 ◽  
Author(s):  
Bambang Heliyanto ◽  
Erik J. Veneklaas ◽  
Hans Lambers ◽  
Siegfried L. Krauss
Keyword(s):  
Breeding System ◽  
Fungal Pathogen ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Genetic Load ◽  
Open Pollination ◽  
Self Pollination ◽  
Hand Pollination ◽  
Self Compatibility ◽  
Non Local

The breeding system of Banksia ilicifolia was assessed by performing controlled hand-pollination manipulations on flowers in a natural population in Perth, Western Australia. The percentage of 2000 flowers per treatment converted to fruits and seeds was assessed across 24 recipient plants following (1) self-pollination, (2) local outcross pollination (same population), (3) non-local outcross pollination (pollen sourced from another population 30 km away), (4) unpollinated but bagged flowers and (5) unpollinated, unbagged flowers (natural pollination). The relative performance of the resulting seeds was assessed by seed weight, germination rates and, in an unplanned component of the study, resistance to a fungal pathogen. The percentage of flowers converted to fruits following self-pollination was low (0.9%), but demonstrated self-compatibility. Fruit set following cross-pollinations (3.6 and 3.3% for non-local and local crosses, respectively) was significantly greater than that following self-pollination, open-pollination (0.4%) and autogamous (0.04%) treatments. Low fruit set for open-pollinated flowers, compared with self- and outcross-pollination treatments, suggests pollen limitation. Pollen tubes were observed in 15 and 20% of upper styles of flowers hand-pollinated with self and local outcross pollen, respectively. Seed germination was dependent on the source of pollen, where fewer selfed seeds germinated (37%) than did both non-local and local outcrossed seeds (83 and 91%, respectively). Selfed seedlings showed poorer survival (33.3%) following fungal attack than both non-local and local outcrossed seeds (69.2 and 68.5%, respectively). Only 13% of selfed seeds survived to be 2-month-old seedlings, compared with 63% for non-local and 57% for local outcrossed seeds. Ultimately, for 2000 flowers hand-pollinated with self pollen, only three seedlings survived to an age of 16 weeks, compared with 37 and 45 seedlings for local-cross and non-local cross treatments on 2000 hand-pollinated flowers, respectively. These results indicate that in this population, B. ilicifolia is self-compatible, but preferentially outcrossing, with strong early acting inbreeding depression. Consequently, the breeding system of B. ilicifolia promotes the maintenance of genetic variation and a high genetic load.

Floral traits, pollination ecology and breeding system of three Clematis species (Ranunculaceae) in Yunnan province, southwestern China

2010 ◽  
Vol 58 (2) ◽  
pp. 115 ◽  
Author(s):  
Nan Jiang ◽  
Wen-Bin Yu ◽  
Hong-Zhe Li ◽  
Kai-Yun Guan
Keyword(s):  
Inbreeding Depression ◽  
Breeding System ◽  
Pollen Limitation ◽  
Mating Strategies ◽  
Breeding Systems ◽  
Floral Traits ◽  
Pollination Syndrome ◽  
Self Pollination ◽  
Hand Pollination ◽  
Integrative Study

Flowers of Clematis display showy corollas and diversified shapes. This diversity motivates study of adaptive evolution of flower–pollinator interactions and the functional association between floral traits and plant mating strategies. An integrative study was undertaken, which focused on pollination and reproductive biology of three species representing all three floral types of Clematis. Floral traits were measured, and pollinator assemblages were observed in the field. Bagging, hand-pollination and removal treatments were used to examine breeding systems. The inbreeding depression and pollen limitation were estimated by fruit-set and seed production obtained from pollination treatments. Their floral traits are distinctly different, but are highly associated with pollination syndrome and breeding system. Among them, Clematis akebioides and C. rehderiana may be facultative autogamy (the former was delayed selfing, and the later competing selfing), and C. chrysocoma may be nearly obligate outcrossing. These conclusions are reflected in their stamen-pistil ratios. The levels of inbreeding depression are negatively associated with autonomous self-pollination. Evolution of self-pollination in C. akebioides and C. rehderiana, and pollen limitation in reproduction of the three Clematis species are discussed. This present study, integrating with previous results, will help us to comprehensively recognise and understand the pollination system and reproductive characteristics of Clematis.

Selective Fruit Abortion in Grevillea barklyana (Proteaceae)

1993 ◽  
Vol 41 (5) ◽  
pp. 499 ◽  
Author(s):  
F Harriss ◽  
RJ Whelan
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Pollen Tubes ◽  
The Other ◽  
Limited Resources ◽  
Pollination Experiments ◽  
Cross Pollination ◽  
Hand Pollination ◽  
Fruit Abortion ◽  
Natural Pollination

The breeding system of Grevillea barklyana F. Muell. ex Benth. was studied using experimental hand pollinations. Fruit set was generally low (less than 5%), and equivalent for autogamy, self-pollination, outcross-pollination and inflorescences left exposed to natural pollination. Pollen tubes were produced in only a low proportion of flowers in the autogamy treatment, with few pollen tubes per flower and short pollen tubes in styles at both 24 and 48 h after anthesis. Selfing and cross-pollination produced equal numbers of pollen tubes in an equivalent and high proportion of flowers (ranging from 40% to 80%). However, pollen tubes resulting from selfing were shorter than from outcrossing after 24 and 48 h. Hand pollination experiments in which half of the flowers on inflorescences were pollinated with self pollen and the other half with outcross pollen generally produced a slightly skewed pattern of fruit set, with a higher proportion of the outcrossed flowers setting fruit. The following processes could contribute to the selective development of outcrossed fruit in this self-compatible species: (1) pollen tubes from outcrossed pollinations reach ovules before those growing from self pollen; (2) fruits that start to develop first obtain first call on limited resources; (3) fruits that are initiated later abort when other fruits on an inflorescence are developing.

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