scholarly journals (239) Evaluation of Self-compatibility in Clethra alnifolia

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1040C-1040
Author(s):  
Sandra M. Reed
Keyword(s):  
Reproductive Behavior ◽  
Pollen Germination ◽  
Native Species ◽  
Seed Set ◽  
Pollen Tubes ◽  
Self Incompatibility ◽  
Lack Of Information ◽  
Incompatibility System ◽  
Self Compatibility ◽  
Deciduous Shrub

Clethra alnifolia, which is commonly known as summersweet, is an attractive deciduous shrub that produces fragrant flower in mid-summer. Breeding efforts are hampered by a lack of information on the reproductive behavior of this native species. The objective of this study was to evaluate self-compatibility in C. alnifolia. Pollen germination and pollen tube growth in styles were examined following self- and cross-pollinations using fluorescence microscopy. Seed set and germination were compared following self- and cross-pollinations. While self-pollen tubes appeared to grow slightly slower than cross-pollen tubes, there was no indication of a self-incompatibility system acting at the stigmatic or stylar level in C. alnifolia. Self-pollinations of `Hummingbird' and `Ruby Spice' produced fewer seeds than did cross-pollinations of these cultivars. Germination of all seed obtained from this study was too poor to allow a comparison of germination rates of the self- and cross-pollinated seed. However, because a few self-progeny were obtained, emasculation is recommended when making controlled pollinations. The presence of a late-acting self-incompatibility system or early acting inbreeding depression was proposed as being responsible for the lower seed set following self-pollination.

scholarly journals Reproductive Biology of Clethra alnifolia

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 567-570
Author(s):  
Sandra M. Reed
Keyword(s):  
Seed Set ◽  
Pollen Tubes ◽  
Self Incompatibility ◽  
Stigma Receptivity ◽  
Flower Opening ◽  
Lack Of Information ◽  
Incompatibility System ◽  
Self Compatibility ◽  
Pollen Shed ◽  
The Relationship

Breeding efforts in Clethra alnifolia L., an ornamental shrub native to the Eastern U.S., are hindered by a lack of information on the reproductive behavior of this species. The objective of this study was to evaluate self-compatibility, time of stigma receptivity, and the relationship between time of pollen shed and stigma receptivity in C. alnifolia. Stigma receptivity and changes in floral morphology were monitored over a 7-day period beginning at flower opening. Pollen germination and pollen tube growth in styles were examined following self- and cross-pollinations using fluorescence microscopy. Seed set and germination were compared following self- and cross-pollinations. Anthers began to dehisce in `Hummingbird' and `Ruby Spice' the day after flowers opened, but stigmas did not become fully receptive to pollen until 2 days later. An increase in the length of pistils was observed following flower opening. Maximum elongation of pistils occurred at approximately the same time stigmas became receptive and could be utilized as an indicator of receptivity. While self-pollen tubes appeared to grow slightly slower than cross-pollen tubes, there was no indication of a self-incompatibility system acting at the stigmatic or stylar level in C. alnifolia. Self-pollinations of `Hummingbird' and `Ruby Spice' produced fewer seeds than did cross-pollinations of these cultivars. Germination of all seed obtained from this study was too poor to allow a comparison of germination rates of the self- and cross-pollinated seed. However, because a few self-progeny were obtained, emasculation is recommended when making controlled pollinations. The presence of a late acting self-incompatibility system or early-acting inbreeding depression was proposed as being responsible for the lower seed set following self-pollination.

scholarly journals Self-incompatibility and Time of Stigma Receptivity in Two Species of Hydrangea

HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 312-315 ◽  
Author(s):  
Sandra M. Reed
Keyword(s):  
Seed Set ◽  
Pollen Tubes ◽  
Tube Length ◽  
Self Incompatibility ◽  
Stigma Receptivity ◽  
Self Pollination ◽  
Incompatibility System ◽  
Self Compatibility ◽  
Days After Anthesis ◽  
Pollen Tube Length

The objectives of this study were to evaluate self-incompatibility in Hydrangea paniculata Sieb. and H. quercifolia Bartr. and to determine optimum time for pollination of these two species. Flowers from three genotypes of each species were collected 1, 2, 4, 8, 24, 48, and 72 hours after cross- and self-pollination, stained with aniline blue and observed using a fluorescence microscope. In both species, pollen germination was observed on stigmas of over half of the flowers collected 4 to 72 hours after cross- or self-pollination. Differences in pollen tube length between cross- and self-pollinated flowers were noted from 8 to 72 hours after pollination in H. paniculata and from 24 to 72 hours after pollination in H. quercifolia. By 72 hours after pollination, most self-pollen tubes had only penetrated the top third of the style but cross-pollen tubes had grown to the base of the style and entered 40% to 60% of the ovules. Stigmas of H. paniculata were receptive to pollen from anthesis to 5 days after anthesis, while stigmas of H. quercifolia were receptive from 1 to 5 days after anthesis. This study provides evidence of a gametophytic self-incompatibility system in H. paniculata and H. quercifolia. Occasional self-seed set previously observed in these species was theorized to have been due to pseudo-self compatibility.

scholarly journals THE UNILATERAL INTERSPECIFIC CROSSING BARRIER IN LYCOPERSICON IS NOT SELF INCOMPATIBILITY

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1079a-1079 ◽  
Author(s):  
Barbara E. Liedl ◽  
Martha A. Mutschler
Keyword(s):  
Pollen Tube ◽  
Pollen Germination ◽  
Seed Set ◽  
Pollen Tubes ◽  
The Other ◽  
Self Incompatibility ◽  
Interspecific Barriers ◽  
Unilateral Incongruity ◽  
Germination And Growth ◽  
Interspecific Crossing

Little is known about the mechanisms controlling interspecific barriers, unlike the well studied intraspecific barrier, self incompatibility (SI),. A unilateral crossing barrier (unilateral incongruity - UI) exists among the Lycopersicon species, in which crossing is impeded or prevented in one direction. Since both UI and SI can give unilateral differences in seed set, suggestions have been made that UI and SI are functionally related. L. pennellii LA716 is self-compatible, unlike the other accessions which are SI, but LA716 still exhibits UI with L. esculentum (esc). We observed the development of pollen tubes in self and cross pollinations of LA716, esc and SI accessions of L. pennellii (pen). Selfed pollen tubes in esc were at the ovary in 24 hours, while pen were 1/2 way down the style and in LA716 the pollen had not germinated. By 48 hours, the pollen tubes in LA716 were in the ovary and growth had halted in pen styles. Crosses with LA716 pollen on esc and pen resulted in pollen tube growth starting within 24 hours continuing to the ovary. Thus, UI is not a SI response and LA716 shows a delayed pollen germination and growth unlike the other Lycopersicon species examined.

scholarly journals A Dual-Successive-Screen Model at Pollen/Stigma and Pollen Tube/Ovary Explaining Paradoxical Self-Incompatibility Diagnosis in the Olive Tree—An Interpretative Update of the Literature

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1938
Author(s):  
Catherine Marie Breton ◽  
Daniela Farinelli ◽  
Georgios Koubouris ◽  
Franco Famiani ◽  
Michel Raymond ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Pollen Germination ◽  
Fruit Set ◽  
Laboratory Data ◽  
Olive Tree ◽  
Pollen Tubes ◽  
Self Incompatibility ◽  
New Model ◽  
Self Compatibility ◽  
Screen Model

The ‘pollen test’ and ‘fruit set test’ following controlled crossing combinations of parents are the most commonly used methods for pollination incompatibility studies in Olea europaea L. Self-incompatibility (SI), with diagnoses based on the pollen test and pollen germination, indicating self-compatibility, is not always followed by fruit set in this species. To solve this dispute, we have reconciled all observations into a new model. Mismatches between field and laboratory data and between methods are resolved by the dual-successive-screen model (DSSM) supposing two different loci for the expression of the two SI mechanisms. Pollen/stigma is controlled by diallelic SI, or DSI, inferring two G1 and G2 compatibility/incompatibility (C/I) groups for varieties, whereas pollen tubes in ovaries are controlled by poly-allelic SI or PASI with twenty C/I groups. To explain the selfing of varieties, we have suggested that some determinants in the pollen tube and stigma are unstable and degrade (DS-D for degradation of S-determinant) after three to five days, enabling some pollen tubes to avoid being rejected, hence reaching ovules. DSI and PASI in the DSSM and DS-D mechanisms, plus the andromonoecy of the olive tree, complexify SI studies. Inferences from DSSM and DS-D mechanisms in olive orchard practice are detailed.

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.

scholarly journals Self-incompatibility in Cornus florida

HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Sandra M. Reed
Keyword(s):  
Growth Rate ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Seed Set ◽  
Pollen Tubes ◽  
Cornus Florida ◽  
Self Incompatibility ◽  
Flowering Dogwood ◽  
Pollen Tube Growth Rate ◽  
Upper Third

Low seed set has been reported following self-pollinations of flowering dogwood (Cornus florida L.). The objective of this study was to verify the presence of self-incompatibility in C. florida. `Cherokee Princess' stigmas and styles were collected 1, 2, 4, 8, 12, 24, 48, and 72 hours after cross- and self-pollinations, stained with aniline blue and observed using a fluorescence microscope. Pollen germinated freely following self-pollinations, but self-pollen tubes grew slower than those resulting from cross-pollinations. By 48 hours after cross-pollination, pollen tubes had reached the bottom of the style while pollen tubes in self-pollinated flowers had only penetrated the upper third of the style. Evidence of reduced pollen tube growth rate in self-pollinations of `Cherokee Chief' and `Cherokee Brave' was also obtained. This study provides evidence of a gametophytic self-incompatibity system in C. florida. It was also determined that stigmas of C. florida `Cherokee Princess' are receptive to pollen from 1 day prior to anthesis to 1 day after anthesis.

scholarly journals Two Self-Incompatibility Sites Occur Simultaneously in the Same Acianthera Species (Orchidaceae, Pleurothallidinae)

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1758
Author(s):  
Mariana Oliveira Duarte ◽  
Denise Maria Trombert Oliveira ◽  
Eduardo Leite Borba
Keyword(s):  
Pollen Tubes ◽  
The Self ◽  
Main Reaction ◽  
Reaction Site ◽  
Self Incompatibility ◽  
Incompatible Pollen ◽  
Plant Groups ◽  
Transmission Electron ◽  
Incompatibility System ◽  
Cytological Characteristics

In most species of Pleurothallidinae, the self-incompatibility site occurs in the stylar canal inside the column, which is typical of gametophytic self-incompatibility (GSI). However, in some species of Acianthera, incompatible pollen tubes with anomalous morphology reach the ovary, as those are obstructed in the column. We investigated if a distinct self-incompatibility (SI) system is acting on the ovary of A. johannensis, which is a species with partial self-incompatibility, contrasting with a full SI species, A. fabiobarrosii. We analyzed the morphology and development of pollen tubes in the column, ovary, and fruit using light, epifluorescence, and transmission electron microscopy. Our results show that the main reaction site in A. johannensis is in the stylar canal inside the column, which was also recorded in A. fabiobarrosii. Morphological and cytological characteristics of the pollen tubes with obstructed growth in the column indicated a process of programmed cell death in these tubes, showing a possible GSI reaction. In addition, partially self-incompatible individuals of A. johannensis exhibit a second SI site in the ovary. We suggest that this self-incompatibility site in the ovary is only an extension of GSI that acts in the column, differing from the typical late-acting self-incompatibility system recorded in other plant groups.

scholarly journals (234) Self-incompatibility in Pink Tickseed, Coreopsis rosea Nutt.

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1001E-1002
Author(s):  
Marietta Loehrlein ◽  
Sandy Siqueira
Keyword(s):  
Genetic Variability ◽  
Seed Production ◽  
Native Species ◽  
Self Incompatibility ◽  
Reproduction Mode ◽  
Landscape Plant ◽  
Incompatibility System ◽  
Made In

Coreopsis rosea is important as a landscape plant and is of some impor-tance for restoration of native species. In both situations it is important to understand the breeding system so that the pollination process may be controlled for optimal seed production. The study of the incompatibility system is important to seed production. In commercial crops, seeds may be products of open pollination or F1 hybrids. In the former, genetic variability exists. In conservation and recovery programs of local flora, seeds with genetic variability are desirable. In development of commercial crops, uniform seeds and plants are desirable. Regardless of whether seeds will ultimately be used for commercial crops or for species restoration, an understanding of self-incompatibility will allow the pollination process to be manipulated for optimal seed production. The purpose of this research was to investigate the sexual reproduction mode in Coreopsis rosea. The objectives were to determine whether Coreopsis rosea operates with a self-incompatibility system, and, if so, to discover whether it is a sporophytic or gametophytic mode. The sporophytic form of self-incompatibility has been found in other plants in the Asteraceae family, but no one has studied self-incompatibility in Coreopsis rosea. The purpose of this research was to identify the self-incompatibility system in Coreopsis rosea. A series of self- and cross-pollinations were made in situ, and in vivo pollinations were made and the pistils studied under the microscope. Results indicate that Coreopsis rosea is self-incompatible and operates under the sporophytic mode.

scholarly journals Pollination Biology of Hydrangea macrophylla

HortScience ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Sandra M. Reed
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Germination ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Self Incompatibility ◽  
Stigma Receptivity ◽  
Hydrangea Macrophylla ◽  
Significant Difference ◽  
Days After Anthesis

Little information is available on the reproductive behavior of Hydrangea macrophylla (Thunb. Ex J.A. Murr.) Ser. The objectives of this study were to investigate time of stigma receptivity, viability of pollen from sterile flowers, and self-incompatibility in this popular ornamental shrub. Pollen germination and pollen tube growth in styles were examined using fluorescence microscopy. Stigma receptivity was examined in cross-pollinations made from 1 day before anthesis to 8 days after anthesis. Maximum stigma receptivity for the two cultivars examined occurred from anthesis to 4 days after anthesis. Viability of pollen from sterile flowers was evaluated through pollen staining and observations of pollen tube growth. No significant difference in percent stainable pollen between fertile and sterile flowers was observed in any of the six taxa examined. Pollen germination and pollen tube growth were studied in cross-pollinations made using pollen from fertile and sterile flowers of two cultivars. For both cultivars, pollen tubes from fertile and sterile flowers grew to the same length and had entered ovules by 72 hours after pollination. Self-incompatibility was evaluated by comparing pollen germination and pollen tube growth in cross- and self-pollinations. In the five taxa examined, self pollen tubes were significantly shorter than cross pollen tubes in flowers that were examined 72 hours after pollination. This finding indicates the presence of a gametophytic self-incompatibility system in H. macrophylla.

scholarly journals When gametophytic self-incompatibility meets gynodioecy

2008 ◽  
Vol 90 (1) ◽  
pp. 27-35 ◽  
Author(s):  
BODIL K. EHLERS ◽  
MIKKEL H. SCHIERUP
Keyword(s):  
Inbreeding Depression ◽  
Self Incompatibility ◽  
S Locus ◽  
Selfing Rate ◽  
Female Function ◽  
Fecundity Selection ◽  
Incompatibility System ◽  
S Alleles ◽  
Self Compatibility

SummaryThe occurrence of gynodioecy among angiosperms appears to be associated with self-compatibility. We use individual-based simulations to investigate the conditions for breakdown of a gametophytic self-incompatibility system in gynodioecious populations and make a comparison with hermaphroditic populations where the conditions are well known. We study three types of mutations causing self-compatibility. We track the fate of these mutations in both gynodioecious and hermaphroditic populations, where we vary the number of S-alleles, inbreeding depression and selfing rate. We find that the conditions for breakdown are less stringent if the population is gynodioecious and that the breakdown of self-incompatibility tends to promote stability of gynodioecious populations since it results in a higher frequency of females. We also find that fecundity selection has a large effect on the probability of breakdown of self-incompatibility, in particular if caused by a mutation destroying the female function of the S-locus.

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