Self-incompatibility in Eucalyptus globulus ssp. globulus (Myrtaceae)

2002 ◽  
Vol 50 (3) ◽  
pp. 365 ◽  
Author(s):  
L. M. Pound ◽  
M. A. B. Wallwork ◽  
B. M. Potts ◽  
M. Sedgley

Controlled pollinations with self- and cross-pollen were applied to individual flowers of five mature Eucalyptus globulus Labill. ssp. globulus trees to investigate the site of action of the self-incompatibility mechanism. Growth of pollen tubes in styles at 2 weeks after pollination and ovule penetration by pollen tubes at 2 and 4 weeks after pollination were investigated by fluorescence microscopy. Some pollinated flowers were left to develop to seed maturity, then harvested to quantify the level of self-incompatibility of each tree. Trees ranged from 76 to 100% self-incompatible. There was no significant difference in the number of pollen tubes in the style between treatments although variation was present between trees. The number of pollen tubes present was similar to the number of ovules present within flowers. Penetration of ovules by pollen tubes over all five trees combined revealed no difference between treatments at 2 weeks after pollination; however, there was slightly greater penetration by cross-pollen tubes at 4 weeks after pollination. This difference was not large enough to account for the near complete lack of selfed-seed production, suggesting late pre- or post-zygotic arrest of selfed ovules.

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.


2013 ◽  
Vol 40 (No. 2) ◽  
pp. 65-71 ◽  
Author(s):  
D. Milatović ◽  
D. Nikolić ◽  
B. Krška

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.      


Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 432
Author(s):  
Yaling Chen ◽  
Benchang Hu ◽  
Fantao Zhang ◽  
Xiangdong Luo ◽  
Jiankun Xie

Dendrobium officinale is a rare and traditional medicinal plant with high pharmacological and nutritional value. The self-incompatibility mechanism of D. officinale reproductive isolation was formed in the long-term evolution process, but intraspecific hybridization of different germplasm resources leads to a large gap in the yield, quality, and medicinal value of D. officinale. To investigate the biological mechanism of self-incompatibility in D. officinale, cytological observation and the transcriptome analysis was carried out on the samples of self-pollination and cross-pollination in D. officinale. Results for self-pollination showed that the pollen tubes could grow in the style at 2 h, but most of pollen tubes stopped growing at 4 h, while a large number of cross-pollinated pollen tubes grew along the placental space to the base of ovary, indicating that the self-incompatibility of D. officinale may be gametophyte self-incompatibility. A total of 63.41 G basesum of D. officinale style samples from non-pollinated, self-pollination, and cross-pollination by RNA-seq were obtained, and a total of 1944, 1758, and 475 differentially expressed genes (DEGs) in the comparison of CK (non-pollinated) vs. HF (cross-pollination sample), CK vs. SF (self-pollination sample) and SF vs. HF were identified, respectively. Forty-one candidate genes related to self-incompatibility were found by function annotation of DEGs, including 6 Ca2+ signal genes, 4 armed repeat containing (ARC) related genes, 11 S-locus receptor kinase (SRK) related genes, 2 Exo70 family genes, 9 ubiquitin related genes, 1 fatty acid related gene, 6 amino acid-related genes, 1 pollen-specific leucine-rich repeat extensin-like protein (LRX) related gene and 1 lectin receptor-like kinases (RLKs) related gene, showed that self-incompatibility mechanism of D. officinale involves the interaction of multiple genes and pathways. The results can provide a basis for the study of the self-incompatibility mechanism of D. officinale, and provide ideas for the preservation and utilization of high-quality resources of D. officinale.


1991 ◽  
pp. 271-283 ◽  
Author(s):  
J. E. Gray ◽  
B. A. McClure ◽  
I. Bonig ◽  
M. A. Anderson ◽  
A. E. Clarke

1993 ◽  
Vol 71 (2) ◽  
pp. 353-358 ◽  
Author(s):  
Lawrence D. Harder ◽  
Mitchell B. Cruzan ◽  
James D. Thomson

To determine whether interspecific pollen transfer could reduce seed production by two sympatric lilies, Erythronium albidum and Erythronium americanum, we hand-pollinated flowers with mixtures of conspecific and heterospecific pollen. These species exhibited typical unilateral interspecific incompatibility, i.e., pollen tubes from the self-infertile species (E. americanum) grew apparently unimpeded in styles of the self-fertile species (E. albidum), whereas the reverse cross resulted in an incompatibility reaction. Because of this asymmetrical relation and faster growth by heterospecific pollen tubes in E. albidum stigmas than by conspecific tubes, pollination with abundant heterospecific pollen reduced fruit and seed production by E. albidum, but not by E. americanum, as long as the stigma also received some conspecific pollen. Unilateral incompatibility could benefit self-infertile species in reproductive interactions with closely related self-fertile species; however, this benefit remains to be demonstrated for naturally pollinated plants. Key words: Erythronium albidum, Erythronium americanum, interspecific pollen transfer, pollination, unilateral incompatibility.


2000 ◽  
Vol 12 (7) ◽  
pp. 1239-1251 ◽  
Author(s):  
Anja Geitmann ◽  
Benjamin N. Snowman ◽  
Anne Mie C. Emons ◽  
Vernonica E. Franklin-Tong

ISRN Agronomy ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Sandra Martins ◽  
Mercè Rovira ◽  
Ana Paula Silva ◽  
Valdemar Carnide

In many higher plants, selffertilization and genetically related individuals are prevented by pollen-stigma incompatibility. In the genus Corylus, incompatibility is of the sporophytic type and controlled by a single locus with multiple alleles. The objective of this study is to identify the S-alleles present in a collection of Portuguese landraces in order to select the most appropriate landraces for establishment of future orchards and for breeding programmes. Ten major Portuguese hazelnut landraces were submitted to controlled pollinations in the field, with 18 genotypes whose S-alleles are known. The pollen tubes were observed at 100X under a florescence microscope to evaluate their development. Three landraces were revealed to have S2 allele, two have S5, and four have one of the S3, S5, S10, and S18 alleles. One landrace was compatible with the 18 S-alleles tested and for two landraces, it was possible to identify both alleles. The information of the self-incompatibility relationship between these old cultivars is obviously useful for selecting the most suitable pollinators for planning new orchards and for new cultivars development.


1997 ◽  
Vol 12 (6) ◽  
pp. 1375-1386 ◽  
Author(s):  
Vernonica E. Franklin-Tong ◽  
Grant Hackett ◽  
Peter K. Hepler

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1758
Author(s):  
Mariana Oliveira Duarte ◽  
Denise Maria Trombert Oliveira ◽  
Eduardo Leite Borba

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.


2005 ◽  
Vol 53 (4) ◽  
pp. 347 ◽  
Author(s):  
M. A. B. Wallwork ◽  
M. Sedgley

Outcrossing was investigated in interspecific hybrids between self-fertile Eucalyptus platypus Blakely and partially self-sterile E. spathulata Hook., which shows both pre- and post-zygotic timing. Four hybrid trees were used for the study, two with E. spathulata and two with E. platypus as female parent. Each hybrid had a similar number of locules to each other and to the E. platypus parent, and an intermediate number of ovules per flower compared with the parent species. Controlled hand-pollinations were carried out, in which both self- and cross-pollen from the other hybrid tree with the same female parent species was applied to flowers on each of the four trees, and observations were made 10days, 4weeks and 8weeks after pollination and at seed maturity. In all hybrids, mean seeds per capsule was consistently higher following cross-pollination than following self-pollination. All hybrids showed a reduction in pollen tube number between the top and base of the style when examined by fluorescence microscopy. One tree had significantly fewer cross- than self-pollen tubes at the base of the style, but a similar number of ovules was penetrated by pollen tubes following both treatments. In the other three, there was no difference between cross- and self-pollination in pollen tubes in the style. In three of the four trees there was no difference in ovule penetration following self- or cross-pollination, but in the other, more crossed than selfed ovules were penetrated. Light-microscopy observation of ovules indicated that ovule abortion following fertilisation accounted for the reduced numbers of seeds following self-pollination and to a lesser extent following cross-pollination. All four hybrid trees, irrespective of female parent, were partially self-sterile and resembled the partially self-sterile E. spathulata rather than the self-fertile E. platypus. While the timing of outcrossing control of E. spathulata was both pre- and post-zygotic, only one hybrid was similar, with the other three showing post-zygotic control.


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