Genetic diversity and differentiation in Chinese sour cherry\ud Prunus pseudocerasus Lindl., and its implications for\ud conservation

In this study, the genetic diversity and differentiation of 10 natural Prunus pseudocerasus Lindl. populations were investigated using inter-simple sequence repeat (ISSR) markers. Totally, 18 selected primers generated 150 loci, with an average of 8.33 bands per primer. The results showed that the percentage of polymorphic bands (PPB) was pretty low at the population level (PPB = 1.13–32%), but relatively high at the species level (PPB = 84%). Besides, a high level of genetic differentiation among populations was detected based on the gene differentiation coefficient (G ST = 0.7118) and the hierarchical analysis of molecular variance (AMOVA) (Φ ST = 64.53%, P < 0.001), in line with the low inter-population gene flow (N m = 0.2025). Moreover, Mantel test revealed a significant correlation between genetic and geographic distances among the populations (r = 0.5272, P < 0.005). The high level of intraspecific genetic diversity was probably related with its life history traits, while its small population size and the resultant high levels of genetic drift and inbreeding might explain the low genetic diversity within populations. The relatively high inter-population genetic differentiation was largely attributed to its small population size, habitat fragmentation, the mode of pollen and seed dispersal, and geographic isolation. Based on the present study, conservation strategies were proposed to preserve this valuable natural germplasm resource

Cherry Breeding: Sweet Cherry (Prunus avium L.) and Sour Cherry (Prunus cerasus L.)

none3noThis chapter describes the cherry’s origins, botanical classification (taxonomy) and domestication of the only two species cultivated for food and industrial processing: sweet and sour cherry. Cherry breeding programs worldwide have focused on trees, fruit quality traits and resistance to biotic and abiotic factors as well as on specific local characteristics. A detailed discussion of breeding techniques (crossbreeding, early selection, seedling screening and field assessment, embryo culture and mutagenesis) follows. A section is dedicated to sour cherry breeding, whose problems differ from those of the sweet cherry. We underline the importance of the knowledge and conservation of genetic resources for their use in genomic approaches. Then, discuss breeding strategies and the new traits that have been introduced in new genotypes through genomics. Germplasm biodiversity is analyzed in its phylogenetic context. Then, the molecular breeding approaches are extensively described with particular attention for gene mapping and the development of marker linked to monogenic and polygenic traits. A section is dedicated to the gametophytic incompatibility of the sweet cherry, with an updated summary of the research conducted to identify the 57 incompatibility groups (the cultivars for each of these are reported). Finally, we take into account other aspects related to breeding in respect to how functional genes affect some fruit characteristics, the strategies used after the cherry genome was sequenced and the potential of genetic engineering. The Appendix provides pomological profiles of 44 of the most important innovative cultivars, according to the descriptive standard of the Brooks and Olmo official lists with each accompanied by original photos to aid in their identification.noneDondini, Luca; Lugli, Stefano; Sansavini, SilvieroDondini, Luca; Lugli, Stefano; Sansavini, Silvier