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.

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.

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 Cordia subcordata (Boraginaceae), a distylous species on oceanic coral islands, is self-compatible and pollinated by a passerine bird

2020 ◽  
Vol 153 (3) ◽  
pp. 361-372
Author(s):  
Xiangping Wang ◽  
Meihong Wen ◽  
Mingsong Wu ◽  
Dianxiang Zhang
Keyword(s):  
Seed Set ◽  
Apis Cerana ◽  
Pollen Grains ◽  
Passerine Bird ◽  
Oceanic Islands ◽  
Self Incompatibility ◽  
Xisha Islands ◽  
Reproduction System ◽  
Hand Pollination ◽  
Zosterops Japonicus

Background and aims – Distyly is usually rare on oceanic islands, which is probably due to the difficulty for distylous plants to colonize those islands. However, Cordia subcordata was observed to be distylous with short- and long-styled morphs on the Xisha Islands in the South China Sea. To characterize the reproduction system of Cordia subcordata and to understand how this distylous species maintains itself on these islands, we studied its reproductive and pollination biology.Methods – Seed set and pollen tube growth under manipulated intermorph, intramorph, and self-pollination were examined to investigate self-incompatibility in the species. The number of pollen grains deposited on the stigmas after a single pollinator visit were counted to investigate the pollination efficiency of different visitors. Key results – Our study indicated that Cordia subcordata shows reciprocal herkogamy as is typical in distylous species. Pollen tubes could reach the base of the style and move into the ovules under all the manipulated pollination treatments in both morphs. Seed set resulting from four hand-pollination experiments did not show any differences between both morphs, suggesting that Cordia subcordata lacks heterostylous self-incompatibility. The most frequent flower visitors, Zosterops japonicus and Apis cerana, were observed foraging on the large volumes of nectar and pollen grains, respectively, with Zosterops japonicus being the most effective pollinator, depositing large number of pollen grains on the stigmas during their visits.Conclusions – Our findings show that Cordia subcordata established itself and persists in the archipelago by producing fruits through a combination of self-compatibility and pollination by the most common passerine bird on the oceanic islands.

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.

scholarly journals A Comparison between Semi- and Fully Compatible Apple Pollinators Grown under Suboptimal Pollination Conditions

HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1280-1282 ◽  
Author(s):  
Doron Schneider ◽  
Raphael A. Stern ◽  
Martin Goldway
Keyword(s):  
General Feature ◽  
Fruit Set ◽  
Seed Set ◽  
The Other ◽  
Pcr Analysis ◽  
Apple Cultivar ◽  
Self Incompatibility ◽  
Cross Pollination ◽  
Hand Pollination ◽  
Golden Delicious

Apple (Malus domestica) has a gametophytic self-incompatibility (GSI) system. Consequently, fertilization is achieved by cross-pollination with a compatible pollinator. Compatibility is governed by a multiallelic S locus. Cultivars are fully compatible when both of their S-loci differ and are semi compatible when one locus is identical and the other differs. In a previous study we found that the fruit set and yield of the apple cultivar `Topred' was reduced when it was pollinated by a semi compatible cultivar. To examine if this occurrence is a general feature in apples grown under suboptimal conditions, three additional cultivars, `Golden Delicious', `Granny Smith' and `Royal Gala', were studied as pollen recipients of semi and fully compatible pollinators. Based on PCR analysis of the S-RNase allele, it was determined that the pollination rate of the semi compatible was significantly lower than that of the fully compatible pollinator in all cases. This was reflected by the lower fruit set and seed set of `Golden Delicious' and `Royal Gala', but not of `Granny Smith'. In hand pollination experiments, where pollen was in excess, no difference was found between the semi and fully compatible pollinators in all three cases. These results indicate that the low yield, conferred by semi compatible pollinators, is due to insufficient cross-pollination (and not to cultivar characteristics). Thus, low yields due to semi compatibility may be avoided by appropriate honeybee management that will increase pollination. Still, under suboptimal conditions, for growth and pollination, full compatibility is preferable.

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.

Pollination studies with highly-inbred lines of winter beans (Vicia faba L.)

1971 ◽  
Vol 77 (2) ◽  
pp. 213-217 ◽  
Author(s):  
Gillian Toynbee-Clarke
Keyword(s):  
Seed Set ◽  
Inbred Lines ◽  
Self Incompatibility ◽  
Breeding Lines ◽  
Flower Pollination ◽  
Mature Flower ◽  
Short Period ◽  
Hand Pollination ◽  
Vicia Faba L ◽  
Using Data

SummaryPollination treatments were carried out on highly inbred lines of winter beans over a period of four years.Tripping produced an inferior seed-set compared with all treatments involving emasculation and hand pollination with either cross or self-pollen. It is suggested that with highly inbred lines the stigmatic surface requires some form of scarification to improve the seed-set. Most lines showed no preference for cross or self-pollen, and there was no evidence of self-incompatibility. Bud and mature flower pollination gave an improved seed-set over tripping in all lines.One inbred line gave a high seed-set in all pollination treatments. Results from another line were consistent with a short period of ovule receptiveness.Using data obtained from three experiments, two self-pollination treatments were used to screen breeding lines for their suitability as components of synthetic varieties. Significant differences in seed-set were found between the lines.

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 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.

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