The objective of our study was the alignment of microsatellite or simple sequence repeat (SSR) marker data across germplasm collections of cherry within Europe. Through the European Cooperative program for Plant Genetic Resources ECPGR, a number of European germplasm collections had previously been analysed using standard sets of SSR loci. However, until now these datasets remained unaligned. We used a combination of standard reference genotypes and ad-hoc selections to compile a central dataset representing as many alleles as possible from national datasets produced in France, Great Britain, Germany, Italy, Sweden and Switzerland. Through the comparison of alleles called in data from replicated samples we were able to create a series of alignment factors, supported across 448 different allele calls, that allowed us to align a dataset of 2241 SSR profiles from six countries. The proportion of allele comparisons that were either in agreement with the alignment factor or confounded by null alleles ranged from 67% to 100% and this was further improved by the inclusion of a series of allele-specific adjustments. The aligned dataset allowed us to identify groups of previously unknown matching accessions and to identify and resolve a number of errors in the prior datasets. The combined and aligned dataset represents a significant step forward in the co-ordinated management of field collections of cherry in Europe.
Superficial scald is a physiological disorder that develops during cold storage affecting apples and causes substantial market losses. Malus × domestica cv. Ladina, a new scab resistant and fire blight tolerant variety, commercialized in 2012, shows a physiological disorder similar to superficial scald after storage. Here, we used different pre- and postharvest approaches to characterize the occurrence of these superficial scald symptoms in Malus × domestica cv. Ladina. Over a period of seven years, fruits from multiple orchards were stored for five to seven months and the occurrence of superficial scald was assessed in fruits after cold storage and controlled atmosphere (CA) storage. Apples picked at different stages of ripeness within the same year differed in superficial scald development. Additionally, superficial scald differed significantly between years and locations, strongly suggesting that maturity at harvest, weather during the growing season, and orchard management play important roles in scald occurrence. Treatment with 1-methylcyclopropene (1-MCP) after harvest, and storage in a dynamically controlled atmosphere (DCA) significantly reduced the occurrence of superficial scald, whereas storage under ultralow oxygen concentrations (ULO) showed mild but not significant effects. Low calcium concentrations in the fruit flesh and peel were associated with stronger superficial scald occurrence.