scholarly journals The evaluation of self-compatibility and crossability in the genus Pyrus based on the observation of pollen tubes growth

2012 ◽  
Vol 59 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Wojciech Antkowiak ◽  
Andrzej Wojciechowski

Interspecific compatibility and self-compatibility in <i>Pyrus communis</i>, <i>P. pyraster</i> and <i>P. salicifolia</i> were evaluated. Degree of compatibility was determined by means of fluorescence microscope. Self-incompatibility evaluated on the basis of the pollen tubes growth showed that two cultivars of <i>P. communis</i> (Bera Hardy and Lukasówka) were self-compatible and the other three cultivars were self-incompatible. All ecotypes of <i>P. pyraster</i> are self-incompatible. In interspecific crosses full inter-incompatibility or unilateral self-incompatibility was observed.


1982 ◽  
Vol 30 (2) ◽  
pp. 175 ◽  
Author(s):  
P Bernhardt

Each of the six Amyema species collected in Victoria had a natural distribution and floral phenoiogy that overlapped with at least one of its Victorian congenerics. All of the Amyema spp. were pollinated by the same family of birds (Meliphagidae, honeyeaters) and often by the same species. All intraspecific cross-pollinations in vitro consistently produced an average of more than five pollen tubes per style which grew more than 0.125 the length of the style within 24 hours. Seventeen of 30 interspecific pollinations in vitro failed to produce pollen tubes in the style over the same time. Only eight of the 30 interspecific crosses attempted produced results competitive with respective intraspecific crosses. The success of the interspecific cross appeared to depend on the breeding system of the species receiving pollen from another. Self-incompatible Amyema pendulum (Sieb. ex Spreng.) Van Tieghem and Amyema miraculosum (Miq.) Van Tieghem repeatedly failed to accept the pollen of all the other species. Seif- compatible Amyema preisii (Miq.) Van Tieghem and Amyema quandang (Lindl.) Van Tieghem showed good to excellent interspecific pollen tube penetration of stylar tissue. Partially self-compatible Amyema linophyllum (Fenzl) Van Tieghem and Amyema miquelii (Lehm. ex Miq.) Van Tieghem showed results intermediate between self-compatible and self-incompatible taxa. Geographic and floral phenological barriers contribute partially to interspecific isolation as intercompatible species may have regionally different flowering seasons and distributions. F, hybrids recorded in southern Australia show extremely low rates of pollen viability and seed production. There is no current evidence that introgression occurs.



2005 ◽  
Vol 130 (6) ◽  
pp. 865-869 ◽  
Author(s):  
José Manuel Alonso ◽  
Rafael Socias i Company

Pollen tube growth after selfing was studied in four almond (Prunus amygdalus Batsch) families derived from crosses between self-compatible `Tuono' and self-incompatible `Ferragnès' and `Ferralise' in both directions, in order to ascertain the phenotypic expressions of the different genotypes. A differential expression of self-compatibility was observed in the seedlings of the different families. The genetic self-compatible offspring of `Ferralise' showed a lower percentage of pistils with pollen tubes at the style base and a lower number of pollen tubes at the pistil base after self-pollination than those observed in the self-compatible offspring of `Ferragnès'. This low level of self-compatibility expression observed in some `Ferralise' seedlings may be due to the inbreeding present in `Ferralise'. As a consequence, caution must be taken in almond breeding to avoid the increase of inbreeding by the utilization of related parents and to diversify the sources of self-compatibility, at present mostly limited to `Tuono.'



HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 567-570
Author(s):  
Sandra M. Reed

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.



HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1079a-1079 ◽  
Author(s):  
Barbara E. Liedl ◽  
Martha A. Mutschler

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.



HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 312-315 ◽  
Author(s):  
Sandra M. Reed

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.



Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1938
Author(s):  
Catherine Marie Breton ◽  
Daniela Farinelli ◽  
Georgios Koubouris ◽  
Franco Famiani ◽  
Michel Raymond ◽  
...  

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.



HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1040C-1040
Author(s):  
Sandra M. Reed

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.



HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 318-320 ◽  
Author(s):  
Nachida Ben-Njima ◽  
_ _

Pollen tube growth was studied in 10 almond [Prunus amygdalus Batsch, syn. P. dulcis (Mill.) D.A. Webb] selections of the Zaragoza breeding program, whose main objective is the development of self-compatible cultivars. Self-compatibility was evident in eight of the selections, as indicated by the fact that pollen tube growth was similar following self- and cross-pollination. In the other two selections, pollen tube growth differed following self- and cross-pollination, one showing self-incompatibility and the other an irregular progression of crossed pollen tubes. The importance of the style in sustaining pollen tube growth was evident, and pollen tube growth was influenced by style type.



Genetics ◽  
1996 ◽  
Vol 143 (4) ◽  
pp. 1739-1752 ◽  
Author(s):  
Xavier Montagutelli ◽  
Rowena Turner ◽  
Joseph H Nadeau

Abstract Strong deviation of allele frequencies from Mendelian inheritance favoring Mus spretus-derived alleles has been described previously for X-linked loci in four mouse interspecific crosses. We reanalyzed data for three of these crosses focusing on the location of the gene(s) controlling deviation on the X chromosome and the genetic basis for incomplete deviation. At least two loci control deviation on the X chromosome, one near Xist (the candidate gene controlling X inactivation) and the other more centromerically located. In all three crosses, strong epistasis was found between loci near Xist and marker loci on the central portion of chromosome 2. The mechanism for this deviation from Mendelian expectations is not yet known but it is probably based on lethality of embryos carrying particular combinations of alleles rather than true segregation distortion during oogenesis in F1 hybrid females.



2021 ◽  
Author(s):  
Marta B Bianchi ◽  
Thomas R Meagher ◽  
Peter E Gibbs

Abstract Background and Aims Genetically controlled self-incompatibility (SI) mechanisms constrain selfing and thus have contributed to the evolutionary diversity of flowering plants. In homomorphic gametophytic SI (GSI) and homomorphic sporophytic SI (SSI), genetic control is usually by a single multi-allelic locus S. Both GSI and SSI prevent self pollen tubes reaching the ovary and so are pre-zygotic in action. In contrast, in taxa with late-acting self-incompatibility (LSI), rejection is often post-zygotic, since self-pollen tubes grow to the ovary where fertilization may occur prior to floral abscission. Alternatively, lack of self fruit set could be due to early-acting inbreeding depression (EID). The aim of our study was to investigate mechanisms underlying lack of selfed fruit set in Handroanthus heptaphyllus in order to assess the likelihood of LSI versus EID. Methods We employed four full sib diallels to study the genetic control of LSI in Handroanthus heptaphyllus using a precociously flowering variant. We also used fluorescence microscopy to study the incidence of ovule penetration by pollen tubes in pistils that abscised following pollination or initiated fruits. Key Results All diallels showed reciprocally cross-incompatible full-sibs (RCI), reciprocally cross compatible full-sibs (RCC), and non-reciprocally compatible full-sibs (NRC) in almost equal proportions. There was no significant difference between the incidence of ovule penetrations in abscised pistils following self- and cross-incompatible pollinations, but those in successful cross pollinations were around twofold greater. Conclusions A genetic model postulating a single S locus with four s alleles, one of which, in the maternal parent, is dominant to the other three, will produce RCI, RCC and NRC situations each at 33 %, consistent with our diallel results. We favour this simple genetic control over an early-acting inbreeding depression (EID) explanation since none of our pollinations, successful or unsuccessful, resulted in partial embryo development, as would be expected under a whole genome EID effect.



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