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.

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 Ovarian Incompatibility in Tuberose (Polianthes Tuberosa L.) Cultivars and Breeding Lines

2021 ◽  
Author(s):  
Thangaraj Usha Bharathi ◽  
Rosalind Lallawmzuali ◽  
Subramanyamrao Prabhakarrao Kirthishree
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Normal Development ◽  
Seed Set ◽  
Interspecific Crosses ◽  
Self Incompatibility ◽  
Interaction Study ◽  
Nucellar Cell ◽  
Breeding Lines ◽  
Controlled Pollination

Abstract Background: Incompatibility occurs frequently in the plant system upon intra- or interspecific crosses resulting in several pollination barriers. The modest understanding on the breeding behaviour and mechanisms governing tuberose (Polianthes tuberosa L.) through this study will direct us to appraise the pollination and post pollination events on self- and cross- incompatibility and seed set behaviour for cross breeding programme.Results: Self-pollination of tuberose cultivars Arka Prajwal, Mexican Single and Arka Sugandhi failed to produce pods upon autogamy and geitonogamy. Pollen-pistil interaction study of incompatible cultivar Arka Prajwal substantiates that pollen tube enters the ovule within 24 hours after pollination. It discharges its contents into the embryo on the 1st day after pollination and polysaccharide granules evident upon fluorescence microscopic study. The pollen tube growth rates of self and controlled pollination were similar; however, sterility was expressed in the ovary. The female gametophytic development in self and cross incompatible cultivar Arka Prajwal showed normal development initially after pollination whereas embryosac degeneration was observed at later stage. Complete degeneration of the integument and nucellar cells was also observed. Conclusions: This study is the first to elucidate the occurrence of pseudo self-incompatibility in tuberose by identifying tuberose cultivars and breeding lines which produce pods upon geitonogamy. A positive pollen-pistil interaction with the degeneration of embryosac, integument and nucellar cell and pod shrinkage, abortion and fall confirms the prevalence of the ‘Ovarian Incompatibility’ or ‘Late-Acting Incompatibility’ in tuberose.

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.

Post-Zygotic Seed Abortion in Sexual Diploid × Apomictic Tetraploid Intraspecific Paspalum Crosses

1994 ◽  
Vol 42 (4) ◽  
pp. 449 ◽  
Author(s):  
GA Norrmann ◽  
OA Bovo ◽  
CL Quarin
Keyword(s):  
Pollen Tube ◽  
Success Rate ◽  
Pollen Tube Growth ◽  
Endosperm Development ◽  
Tube Growth ◽  
Seed Abortion ◽  
Self Incompatibility ◽  
Incompatible Pollen ◽  
Incompatibility System

In many species of Paspalum, diploid (2x) cytotypes are usually outbreeders due to a self incompatibility system, while tetraploid (4x) conspecific counterparts are pseudogamous self-fertile apomicts. Intraspecific crossability between 2x female and 4x male cytotypes was investigated using classical methods of crossing in P. almum, P. brunneum, P. rufum, P. intermedium and P. quadrifarium. Expected triploid BII hybrids were obtained in P. intermedium (crossability: 0.004%) and in P. brunneum (crossability: 0.015%). In P. rufum, only tetraploid BIII hybrids were achieved with a crossability of 0.025% Looking for a better performance, in vitro ovary rescue was attempted 5 days after pollination in intraspecific 2x × 4x crosses of P. almum, P. quadrifarium, P. intermedium and P. rufum. The method was useful to recover some triploid BII hybrids in P. almum (success rate: 0.49%) and in P. rufum (0.59%), but failed in P. intermedium and P. quadrifarium. Pollen tube growth was usually inhibited at the stigma or style levels after self-pollination in 2x plants, confirming that diploids are self-incompatible. Pollen of 4x cytotypes germinated and penetrated the pistils of diploid conspecific cytotypes. This indicated that no incompatibility system exists in these species to keep the 2x cytotypes from hybridising with 4x conspecific cytotypes as pollen donors. However, after pollination of 2x cytotypes with pollen of 4x counterparts, most ovules showed embryo and endosperm development, but a few days later, endosperms collapsed and embryos stopped their development. As a result of these processes, sexual self-incompatible 2x cytotypes of Paspalum species produced very few triploid hybrids when pollinated with pollen of their apomictic 4x counterparts. Thus, the low diploid-tetraploid crossability was due to the existence of a post-zygotic abortive system and not caused by pre-fertilisation barriers.

scholarly journals 459 PB 338 SELF INCOMPATIBILITY (SI) IN DISTYLOUS LYTHRUM ALATUM, WINGED LOOSESTRIFE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 497a-497 ◽  
Author(s):  
Neil O. Anderson ◽  
Peter D. Ascher
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Seed Set ◽  
Tube Growth ◽  
Self Incompatibility ◽  
Visual Identification

Lythrum species (Lythraceae), found both in the Old and New Worlds, possess heterostyly (macroscopic differences in anther and style lengths). SI is linked with heterostyly in tristylous L. salicaria, allowing for visual identification of compatibility relationships. Five Minnesota populations of distylous L. alatum (short & long styles/anthers) were examined for fertility and linkage between distyly and SI. Pollen was not inhibited from germination, stigmatic penetration, or stylar growth in compatible crosses. Average cross-compatible seed set for each population was 7-33 seeds/capsule for short- and 27-69 for long-styled plants. With the exception of the Iron Horse Prairie population, there were no significant differences in mean seed set/capsule between genotypes, style morphs, or their interaction for compatible crosses. Zero self seed set predominated, although 0.8±1.8 seeds/capsule were produced by short styles and 1.2 ±2.3 by long styles from Iron Horse Prairie. In those individuals that were SI, pollen tube growth was inhibited following self pollinations.

scholarly journals Testing of self-(in)compatibility in apricot cultivars from European breeding programmes

2013 ◽  
Vol 40 (No. 2) ◽  
pp. 65-71 ◽  
Author(s):  
D. Milatović ◽  
D. Nikolić ◽  
B. Krška
Keyword(s):  
Fluorescence Microscopy ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Reliable Method ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Self Incompatibility ◽  
Breeding Programmes

Self-(in)compatibility was tested in 40 new apricot cultivars from European breeding programmes. Pollen-tube growth in pistils from laboratory pollinations was analysed using the fluorescence microscopy. Cultivars were considered self-compatible if at least one pollen tube reached the ovary in the majority of pistils. Cultivars were considered self- incompatible if the growth of pollen tubes in the style stopped along with formation of characteristic swellings. Of the examined cultivars, 18 were self-compatible and 22 were self-incompatible. Fluorescence microscopy provides a relatively rapid and reliable method to determine self-incompatibility in apricot cultivars.      

Onset and duration of stigma receptivity in Kunzea pomifera (Myrtaceae)

2006 ◽  
Vol 54 (6) ◽  
pp. 559 ◽  
Author(s):  
T. Page ◽  
G. M. Moore ◽  
J. Will ◽  
G. M. Halloran
Keyword(s):  
Pollen Tube ◽  
Reproductive Biology ◽  
Peroxidase Activity ◽  
Pollen Tube Growth ◽  
Seed Set ◽  
Stigma Receptivity ◽  
Controlled Pollination ◽  
Germinated Pollen ◽  
New Crop ◽  
Days After Anthesis

The onset and duration of stigma receptivity in K. pomifera was evaluated by observing stigma peroxidase activity, pollen-tube growth and seed set, following controlled pollination of flowers of different ages. Peroxidase activity was negligible from 1 day before to 4 days after anthesis, increasing to a peak of 65% at Day 13. The percentage of pistils bearing germinated pollen and ovaries exhibiting pollen-tube entry increased when pollen was applied to the stigma from the day before anthesis, to a maximum at Days 6 and 7 after anthesis, respectively, followed by a decline by Day 9. Under greenhouse conditions the optimum pollination period, measured as the level of set seed after pollination, ranged from 2 to 11 days after anthesis. The knowledge of this aspect of the species reproductive biology is of considerable value in controlled pollinations for its improvement as a new crop.

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