scholarly journals A molecular basis for the self-incompatibility system operating in Brassica sp.

2014 ◽  
Vol 50 (1-2) ◽  
pp. 227-234 ◽  
Author(s):  
H. G. Dickinson ◽  
I. N. Roberts
Keyword(s):  
Breeding System ◽  
Molecular Basis ◽  
Pollen Grain ◽  
The Self ◽  
Self Incompatibility ◽  
Atmospheric Water ◽  
Incompatibility System ◽  
Pollen Coating ◽  
Stigmatic Papillae ◽  
System Operating

Molecules contained in the sporophytically-derived coating of the pollen grain and in the superficial pellicle of the stigmatic papillae control the self-incompatibility response of the breeding system of <em>Brassica</em>. The stigmatic pellicle consists of a lipidic matrix in which float a mosaic of proteins many of which can rapidly be renewed from pools in the papillar cyto-plasm. A fraction of these proteins are involved in facilitating the passage of water to the pollen whilst another, possibly a glycoprotein, suppresses this activity in an incompatible mating. The pollen coating must also contain two sets of active molecules, one for identifying the stigmatic recognition molecules, and another for effecting the changes that take place tothe coat itself on compatible pollination. In essence, the self -incompatibility mechanism appears to operate through the control of water flow from 'the papilla to the grain. Even when incompatible grains manage to germinate by obtaining atmospheric water, their proteins will often stimulate a reaction in the stigmatic papilla once the cuticle has been penetrated.

The formation of the tryphine coating the pollen grains of Raphanus , and its properties relating to the self-incompatibility system

1973 ◽  
Vol 184 (1075) ◽  
pp. 149-165 ◽  
Keyword(s):  
Granular Material ◽  
Pollen Grains ◽  
The Self ◽  
Self Incompatibility ◽  
Pollen Maturation ◽  
Incompatible Pollen ◽  
Incompatibility System ◽  
Two Stages ◽  
Stimulation Of ◽  
Incompatible Pollen Tube

The tryphine that coats the pollen grains of Raphanus is tapetally synthesized and is composed of a fibro-granular and a lipidic component. The fibro-granular material is proteinaceous and is secreted by cisternae of the endoplasmic reticulum. The lipidic component is derived, mainly, from degraded elaioplasts. The fibro-granular material is applied to the pollen exine first, followed by the lipidic mass. The tryphine condenses during the final stages of pollen maturation and dries down to form a thick, highly viscous coating. The major part of the condensation appears to result from dehydration. The tryphine, extracted from the pollen by a centrifugal method and mounted in a membrane, appears to be capable of penetrating the outer layers of a stigma of the same species and, if the pollen from which it was derived is incompatible with respect to the stigma, the stimulation of the production of the callosic reaction body in a manner similar to an incompatible pollen tube. It is proposed that, in Raphanus , substances responsible for the initiation of at least two stages in the self-incompatibility system are held in the tryphine.

Breeding System, Karyotype and Variation Within and Between Populations of Rutidosis leptorrhynchoides F Muell (Asteraceae, Inuleae)

1991 ◽  
Vol 39 (1) ◽  
pp. 85 ◽  
Author(s):  
P Leeton ◽  
YJ Fripp
Keyword(s):  
Chromosome Number ◽  
Breeding System ◽  
Geographic Distance ◽  
Endangered Plant ◽  
Allozyme Analysis ◽  
Self Incompatibility ◽  
Eastern Australia ◽  
Incompatibility System ◽  
Leaf Dimensions ◽  
Allozyme Loci

The endangered plant species, Rutidosis leptorrhynchoides (button wrinklewort), is now known from only a few populations in each of two regions separated by approximately 500 km in south-eastern Australia. Plants were examined from several populations from each region. No differences in chromosome number or morphology were observed among plants or populations. All counts were diploid, 2n = 26. Viable progeny were obtained following self-pollination and allozyme analysis indicated that these progeny were the result of selfing and not agamospermy. This species is not an obligate outcrosser and does not have a classical pre-zygotic self-incompatibility system. However, outcross pollen may have an advantage over self pollen and this species may thus be preferentially outcrossing. The pollen: ovule ratios (mean 3186 ± 48.5) were consistent with this hypothesis. Allele frequencies at allozyme loci diferred little between populations, with an estimated 97% of the variation within populations. There was no correlation between genetic distance and geographic distance. In contrast, for the leaf dimensions of plants germinated and raised together in a glasshouse there were differences between plants from the two regions. It is recommended that populations from both regions should be conserved.

Cytochemical and ultrastructural differences between intraspecific compatible and incompatible pollinations in Raphanus

1973 ◽  
Vol 183 (1070) ◽  
pp. 21-38 ◽  
Keyword(s):  
Pollen Tube ◽  
The Self ◽  
Self Incompatibility ◽  
Second Stage ◽  
Incompatible Pollen ◽  
Large Numbers ◽  
Third Stage ◽  
Incompatibility System ◽  
Three Stages ◽  
Two Stages

Examination of the behaviour of pollen on the style of Raphanus , following compatible and incompatible intraspecific pollinations, has revealed the self-incompatibility system in this species to be composed of at least three stages. The first, on which no information has been obtained in this study, involves the germination of the grain. The second stage concerns the ability of the pollen tube to penetrate the cuticle of the stigmatic papilla. It is possible that cutinase is deficient in incompatible pollen tubes but, in most instances, the outer layers of the stigmatic wall are penetrated. The third stage involves the interaction of substances secreted by the pollen tube with products of the stigmatic cytoplasm. The interaction is swiftly followed by the deposition, in the stigma, of a layered callosic body. This is formed immediately under the point of penetration and takes about 6 h to develop fully. Development of the pollen tube ceases as the first layers of callose are laid down. It is possible that the substances in the pollen responsible for the initiation of the second two stages are held in the tapetally synthesized tryphine, thus accounting for the sporophytic control of pollen compatibility in this species. The mature stigma contains large numbers of crystalline protein bodies, but it is not known whether they play any role in the self-incompatibility system.

scholarly journals Controlling for genetic identity of varieties, pollen contamination and stigma receptivity is essential to characterize the self-incompatibility system ofOlea europaeaL.

2017 ◽  
Vol 10 (9) ◽  
pp. 860-866 ◽  
Author(s):  
Pierre Saumitou-Laprade ◽  
Philippe Vernet ◽  
Xavier Vekemans ◽  
Vincent Castric ◽  
Gianni Barcaccia ◽  
...  
Keyword(s):  
The Self ◽  
Genetic Identity ◽  
Self Incompatibility ◽  
Stigma Receptivity ◽  
Pollen Contamination ◽  
Incompatibility System

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 Plasticity in the self-incompatibility system of Solanum carolinense

2004 ◽  
Vol 19 (3) ◽  
pp. 127-135 ◽  
Author(s):  
STEVEN E. TRAVERS ◽  
JORGE MENA-ALI ◽  
ANDREW G. STEPHENSON
Keyword(s):  
The Self ◽  
Self Incompatibility ◽  
Solanum Carolinense ◽  
Incompatibility System
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