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 ◽  
...  
1973 ◽  
Vol 184 (1075) ◽  
pp. 149-165 ◽  

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.


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.


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.


2004 ◽  
Vol 19 (3) ◽  
pp. 127-135 ◽  
Author(s):  
STEVEN E. TRAVERS ◽  
JORGE MENA-ALI ◽  
ANDREW G. STEPHENSON

Author(s):  
J. Halász ◽  
A. Hegedűs ◽  
A. Pedryc

This review gives a presentation of the gametophytic self-incompatibility system in the roscaeous fruit trees. Studies to discover the pistil (S-ribonucleases) and pollen-part components (F-box molecules) are summarized and models for the self-incompatibility reactions as well as their molecular background are discussed. We describe how mutations within the S-RNase or F-box genes can contribute to the transition from self-incompatibility to the self-compatible phenotype in many fruit tree crops. The current state of the arts is compared to the information obtained in other plant species possessing similar incompatibility system.


Polar Record ◽  
2002 ◽  
Vol 38 (206) ◽  
pp. 219-224
Author(s):  
Marianne Philipp

AbstractA comparison of the population genetic structure of Armeria maritima in Iceland with an earlier study in Denmark was undertaken. Ten populations were sampled in Iceland for isozyme analysis. Most populations showed Hardy-Weinberg proportions, but a higher number than statistically expected possessed too many homozygotes. This could indicate a breakdown of the self-incompatibility system in some cases. Statistically significant differences in allelic frequencies among populations were observed but no positive correlation between genetic distance and geographic position was found. Gene diversity in Iceland was lower than in Denmark although the alleles occurring in Iceland were the same as those found in Denmark. Missing alleles were those found with lowest frequency in Denmark. It is suggested that A. maritima in Iceland has immigrated from the southern part of the distribution post-glacially, leaving behind the rare alleles.


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