Molecular and phenotypic characterization of the S-locus and determination of flowering time in new ‘Marcona’ and ‘Desmayo Largueta’-type almond (Prunus dulcis) selections

Abstract

Marcona' and 'Desmayo Largueta' are the most widely cultivated almonds in Spain, representing around 27% of the total production and 34% of the entire almond growing surface. The excellent quality of their kernels makes them highly appreciated and demanded worldwide. However, due to their selfincompatibility, they should be grown along with cross-compatible cultivars, whose lower kernel quality often reduces the economic benefits of the plantation. In addition, although they are cross-compatible, are not good candidates to share the orchard since 'Desmayo Largueta' usually flowers earlier than 'Marcona'. Therefore, to optimize orchard yield, genotypes with overlapping flowering times, cross-compatible with these cultivars and of similar fruit and ripening characteristics are desirable. In order to find suitable pollinators of these cultivars, five 'Marcona' and four 'Desmayo Largueta'-type selections from ''Instituto Técnico Agronómico Provincial (ITAP) de Albacete'' (Spain) were characterized for flowering time and for self and cross-incompatibility. The results obtained showed that the nine ITAP selections were self-incompatible, and that three and one were promising candidates as pollinators of 'Marcona' and 'Desmayo Largueta', respectively. The S-haplotypes of two ITAP selections were characterized by cloning and sequencing their pistil S (S-RNase) and pollen S (SFB) genes. The results also showed that S f RNase does not have a mutated histidine in C2 region, and detected differences with other previously published sequences for S 23 RNase and SFB 23 allele. Moreover, the sequence for almond SFB 27 allele is reported here for the first time.

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

“…A table of almond cross-incompatibility was constructed using the results of the present work and the plentiful data reported by other authors (Ortega et al, 2006;López et al, 2006;Barckley et al, 2006;Kodad et al, 2008;Valizadeh et al, 2009;Kodad and Socias i Company, 2009;Halász et al, 2010;Kodad et al, 2010;Fernández i Martí et al, 2010;Martínez-García et al, 2011;Mousavi et al, 2011;Hafizi et al, 2013;Curró et al, 2015). This new table was not intended to be merely an update of the earlier ones, but a compilation or review table in which all the self-incompatible almond cultivars S-genotyped to date were to be included, and thus it was made after an accurate correction of the inconsistencies detected in previous works.…”