During the last decade, S-genotyping has been extensively investigated in fruit tree crops such as those belonging to the Prunus genus, including plums. In plums, S-allele typing has been largely studied in diploid species but works are scarcer in polyploid species due to the complexity of the polyploid genome. This study was conducted in order to analyze the S-genotypes of 30 diploid P. salicina, 17 of them reported here for the first time, and 29 hexaploid plums (24 of P. domestica and 5 of P. insititia). PCR analysis allowed identifying nine S-alleles in the P. salicina samples allocating the 30 accessions in 16 incompatibility groups, two of them identified here for the first time. In addition, pollen tube growth was studied in self-pollinated flowers of 17 Tunisian P. salicina under the microscope. In 16 samples, including one carrying the Se allele, which has been correlated with self-compatibility, the pollen tubes were arrested in the style. Only in one cultivar (“Bedri”), the pollen tubes reached the base of the style. Twelve S-alleles were identified in the 24 P. domestica and 5 P. insititia accessions, assigning accessions in 16 S-genotypes. S-genotyping results were combined with nine SSR loci to analyze genetic diversity. Results showed a close genetic relationship between P. domestica and P. salicina and between P. domestica and P. insititia corroborating that S-locus genotyping is suitable for molecular fingerprinting in diploid and polyploid Prunus species.

22 Pags. The definitive version, with Figures, is available at: http://www.sciencedirect.com/science/journal/03044238Mango (Mangifera indica L.) is a tropical fruit tree originated from Southeastern Asia, which is cultivated worldwide in regions with tropical and subtropical climates. Mango cultivation area has significantly extended in the last decades often to regions where environmental conditions are not the most favourable for optimal mango flower development and fruit set and, consequently, several reproductive problems had been described in this species. Some of them could be related to self-incompatibility, but so far information is not clear on the possible self-incompatibility system operating in this crop. In this work we study pollen tube growth, following self and cross pollination, in three mango cultivars (‘Osteen’, ‘Kent’ and ‘Kensington’). Paternity was also determined in the offspring of two of these cultivars – ‘Osteen’ and ‘Kent’ – and in a solid block of an additional cultivar, ‘Keitt’. Sequential examination of pollen tube growth showed that pollen tubes grew to the base of the style in both cross- and self-pollinated pistils of the different cultivars examined. Paternity analysis of ‘Osteen’ and ‘Keitt’ offspring in monovarietal orchards showed the production of fruits resulting from self-fertilization in both cultivars. The results from the multivarietal orchard corroborate this fact for ‘Osteen’ and ‘Kent’, but showed a preference for outcrossing in ‘Osteen’. Pollen tube behaviour and paternity analysis show self-fertility in this species but the higher proportion of fruits resulting from outcrossing suggests a preference for cross-fertilization.The research was supported by the Ministerio de Economía y Competitividad—European Regional Development Fund, European Union (AGL2012-40239, AGL2013-43732-R, AGL2016-77267-R and Recupera2020) and Gob. Aragón A-43. V. Pérez was supported by a Cabildo de La Palma- CSIC PhD scholarshipPeer reviewe

Peach (Prunus persica) is an economically important temperate fruit crop due to its edible fruits. Due to the need to develop new varieties better adapted to climate change, it is of great interest to find germplasm adapted to warmer conditions, such as those found in the Canary Islands. Peach was an important crop during the last century in one of those islands (La Palma), but its cultivation has been abandoned in recent years. Currently, commercial production is relict and isolated trees are relegated to family orchards with little management. With the objective to characterize and prevent the loss of local varieties of this crop, peach trees were sampled along La Palma. A total of 89 local peach accessions were prospected and analyzed with 10 single-sequence repeat (SSR) loci, which permitted 28 different genotype profiles to be detected. These genotypes were compared to 95 Spanish peach landraces conserved in an ex situ collection, and 26 additional samples from eight different countries. Results showed that the peach genetic diversity found in La Palma was low. In addition, a relation between La Palma samples and other Spanish peaches was observed, which could indicate the arrival of genetic material from the Iberian Peninsula and subsequent intercrossing and local selection of the genotypes more adapted to the subtropical climate of the island. The population structure reflects a grouping of the samples based on fruit type and geographic origin.

de la Peña, E., Pérez, V., Alcaráz, L., Lora, J., Larrañaga, N., Hormaza, I. 2018. Polinizadores y polinización en frutales subtropicales: implicaciones en manejo, conservación y seguridad alimentaria. Ecosistemas 27(2): 91-101. Doi.: 10.7818/ECOS.1480 La demanda de frutas tropicales ha crecido durante la última década y esta tendencia sigue aumentando debido al incremento de la población mundial y a la mayor demanda que hay de estos productos en los mercados occidentales. Uno de los cuellos de botella en su producción es la polinización y el subsecuente manejo de los insectos polinizadores. Este manejo es además un factor determinante para la diversidad de los agrosistemas. La intensificación en la producción en muchas zonas del mundo requiere una gestión adecuada de los cultivos para permitir: (1) una producción óptima; (2) la conservación de las comunidades de polinizadores nativas y locales. Esto es particularmente acuciante en países en desarrollo donde la diversidad de polinizadores es poco conocida, pero, a la vez, está amenazada por la pérdida de hábitat como consecuencia de la intensificación agrícola. Algunos de estos cultivos se han introducido en áreas alejadas de las áreas nativas de origen, lo que es un desafío desde un punto de vista agronómico, pero brinda una oportunidad para estudiar en condiciones controladas nuevas estrategias de manejo acordes con una producción sostenible. En este trabajo presentamos una revisión sobre polinizadores y polinización en frutales subtropicales centrándonos en tres especies como son el mango, el aguacate y el chirimoyo. En base al conocimiento adquirido en un ámbito mediterráneo, planteamos una hoja de ruta para desarrollar estrategias de manejo adecuadas para otros cultivos y ámbitos geográficos. Pollinators and pollination in subtropical fruit crops: management and implications for conservation and food security de la Peña, E., Pérez, V., Alcaráz, L., Lora, J., Larrañaga, N., Hormaza, I. 2018. Pollinators and pollination in subtropical fruit crops: management and implications for conservation and food-security. Ecosistemas 27(2): 91-101. Doi.: 10.7818/ECOS.1480 The commercialization and consumption of tropical fruits has grown worldwide during the last decade. This trend is expected to continue, due to the increasing world population and the greater demand for these products in western markets. As in most fruit crops, one of the main bottlenecks in production is pollination, which determines fruit-tree and pollinator management to a large extent. Pollination management is therefore a defining factor in the composition and diversity of agro-systems. Because of this, the intensive production of fruit crops in many areas of the world requires adequate management of crops to enable: (1) an optimal production of fruit crops; (2) the conservation of insect communities. This is particularly important in developing countries, where the centers of genetic diversity of these crops are generally found and pollinator diversity is often poorly known and seriously threatened by agricultural intensification. However, some of these crops have been introduced into geographic areas away from the native areas of origin, which is an agronomic challenge but, at the same time, provides an opportunity to study and test under controlled conditions new management strategies. In this work we present a brief review on pollinators and pollination in subtropical fruit crops focusing on three species of international economic relevance such as mango, avocado and cherimoya. With the knowledge acquired on these species in a Mediterranean context, we propose a road-map to develop appropriate management strategies in other fruit crops and geographical areas.

A plum collection located in the island of La Palma, Canary Islands, composed of twenty-nine European and Japanese plums was analyzed using nine simple sequence repeat (SSR) highly polymorphic loci. First, a cytometry flow analysis was performed to determine the ploidy level. Sixteen accessions turned out diploid and thirteen hexaploid. According to morphological characteristics, fourteen of the sixteen diploid accessions were assigned to Prunus salicina, and two accessions to P. cerasifera. All the hexaploid accessions were assigned to P. domestica. The 29 accessions were compared using SSR markers with twenty-two P. domestica accessions maintained at the CITA plum germplasm collection located in Zaragoza, Aragón, Spain. A principal component analysis (PCA) and a clustering approach grouped the accessions according to the assigned species and geographical location, while some synonyms and homonyms were found within La Palma accessions. The two principal components explained 80.3% (67.3% and 13%, respectively) of the total variance. A tree generated with UPGMA hierarchical clustering and Bruvo distance grouped the accessions in two main clusters according to ploidy level and species assignment. The STRUCTURE approach clearly differentiated La Palma diploid accessions and some of the hexaploid accessions from those of the CITA collection. The results obtained could be used for management and conservation purposes of this valuable local plum germplasm.