Cross-incompatibility in the cultivated almond (Prunus dulcis): Updating, revision and correction

Abstract

Most almond cultivars are self-incompatible, and so to obtain a yield they need to be pollinated with cross-compatible cultivars. For an efficient use of these cultivars in growing and breeding, over the years many have been S-genotyped. This information has been included in consecutive tables of crossincompatibility groups, which are essentially an update of the previously proposed. However, the information of these tables has not always been reconciled and their inconsistencies have not been corrected. In this work the S-genotypes of 15 Spanish almond local cultivars, included in a research program for the preservation of almond biodiversity, were determined for the first time. For this, PCR with consensus primers for the Prunus S-RNases, PCR using S-RNase allele specific primers designed herein, and also cloning and sequencing were performed. As a result, a new S-RNase allele numbered as S53 could be identified, and a compilation table of almond cross-incompatibility groups is provided including the information from this and previous studies. In this novel Table 12 new crossincompatibility groups have been established, two former groups were omitted, and those cultivars with inconsistent genotypes have been removed. The information of this table will facilitate the use of a very high number of almond cultivars in research and breeding. Determination of the S-genotype might be considered as an important addition to a set of identity markers of almond genetic resources, what is of particular interest in the characterization of the agricultural biodiversity.

Revealing the Genetic Components Responsible for the Unique Photosynthetic Stem Capability of the Wild Almond Prunus arabica (Olivier) Meikle

“…This may indicate that the SNPs in that region could be placed in or near a lethal allele, which its presence in the progeny is not favorable. Such an allele, for example, could be an incompatibility S allele ( Gómez et al, 2019 ).…”

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

“…The seemingly large number of 23 distinct putative S-RNases in cherry laurel is not unprecedented, since up to now more than 30 S -alleles have been identified in several other Prunus species, including apricot, almond, or sweet cherry ( Cachi et al, 2017 ; Herrera et al, 2018 ; Gómez et al, 2019 ). In contrast, peach, a generally SC species was reported to have only four S -alleles ( Hanada et al, 2014 ).…”

Comparative floral ecology and breeding systems between sympatric populations of <i>Nothoscordum bivalve</i> and <i>Allium stellatum</i> (Amaryllidaceae)

“…The form of compatibility in N. bivalve appears similar to other known cases of intraspecific cross-incompatibility. However, those are cases of inbreeding depression caused by crossing self-incompatible but genetically similar cultivars within the same domesticated species (Egea & Burgos 1996;Gómez et al 2019). Intraspecific cross-incompatibility has never been observed in self-compatible populations, wild populations, or populations that have experienced outbreeding depression to our knowledge.…”