Evaluation of the S-locus in Prunus domestica, characterization, phylogeny and 3D modelling

Abstract

Self-compatibility has become the primary objective of most prune (Prunus domestica) breeding programs in order to avoid the problems related to the gametophytic self-incompatibility (GSI) system present in this crop. GSI is typically under the control of a specific locus., known as the S-locus., which contains at least two genes. The first gene encodes glycoproteins with RNase activity in the pistils., and the second is an SFB gene expressed in the pollen. There is limited information on genetics of SI/SC in prune and in comparison., with other Prunus species, cloning., sequencing and discovery of different S-alleles is very scarce. Clear information about S-alleles can be used for molecular identification and characterization of the S-haplotypes. We determined the S-alleles of 36 cultivars and selections using primers that revealed 17 new alleles. In addition, our study describes for the first time the association and design of a molecular marker for self-compatibility in P. domestica. Our phylogenetic tree showed that the S-alleles are spread across the phylogeny, suggesting that like previous alleles detected in the Rosaceae., they were of trans-specific origin. We provide for the first time 3D models for the P. domestica SI RNase alleles as well as in other Prunus species, including P. salicina (Japanese plum), P. avium (cherry), P. armeniaca (apricot), P. cerasifera and P. spinosa.

The Self-incompatibility Locus and Chloroplast DNA Regions of Prunus domestica Reflect the Origin and Genetic Diversity of Traditional Cultivars

“…Most studies published so far have assigned fewer than six alleles to a range of P. domestica cultivars (Fernandez i Marti et al 2021;Hal asz et al 2014;Sutherland et al 2004b), the complete S-genotype could have been only proposed for a single cultivar (Abdallah et al 2019). The reasons for the fewer S-RNase alleles detected may involve the preferential amplification of a subset of those by consensus primers (Brace et al 1994), more copies of the same allele might be carried by the polyploid genome (Esselink et al 2004) or a partial deletion in a chromosome 6 homeolog, similar to what has been reported for S null in Prunus cerasus (Yamane et al 2001).…”

“…Its genetic background is complex because six S-alleles are expected to be present in a hexaploid plum genome. In plums, several self-incompatibility ribonuclease (S-RNase) alleles were identified (Abdallah et al 2019;Fernandez i Marti et al 2021;Hal asz et al 2014;Sutherland et al 2004bSutherland et al , 2008 and from two to six alleles were assigned to the studied cultivars. However, the molecular background of self-compatibility in this species is still to be clarified.…”

Unlocking Plum Genetic Potential: Where Are We At?

“…Genetic and morphological studies of several local plum germplasm have been carried out for numerous European countries such as Norway and Sweden [88], Spain [89], Slovenia [90]; Croatia [64]; Serbia, Bosnia and Herzegovina, Macedonia and Montenegro [91]; Bulgaria [92,93]; Hungary [94]; Romania [95,96]; Italy [15,76,[97][98][99][100] or for accessions of mixed provenance [19,49,[101][102][103], also including, inter alia, Denmark, Estonia, Latvia, Belgium, Great Britain, Germany, the Czech Republic, Greece and Slovakia. These studies, aimed at validating the pomological/taxonomic classification in use within the heterogeneous European plums and assessing their genetic diversity, represent a valuable contribution to the conservation, knowledge, and use of the plum germplasm for breeding purposes, thus possibly closing the existing gap of reliable morphological and molecular data [57].…”

“…Genetic and morphological studies of several local plum germplasm have been carried out for numerous European countries such as Norway and Sweden [88], Spain [89], Slovenia [90]; Croatia [64]; Serbia, Bosnia and Herzegovina, Macedonia and Montenegro [91]; Bulgaria [92,93]; Hungary [94]; Romania [95,96]; Italy [15,76,[97][98][99][100] or for accessions of mixed provenance [19,49,[101][102][103], also including, inter alia, Denmark, Estonia, Latvia, Belgium, Great Britain, Germany, the Czech Republic, Greece and Slovakia.…”

Identification and Molecular Analysis of Putative Self-Incompatibility Ribonuclease Alleles in an Extreme Polyploid Species, Prunus laurocerasus L.

“…However, when the pollen grain contains at least one fully functional S -haplotype that has a match in the pistil, SI prevails. The analysis of the S -locus of hexaploid P. domestica L. has been initiated recently ( Abdallah et al, 2019 ; Fernandez i Marti et al, 2021 ).…”