Search

Peaches with low acidity are preferred in the market and this trait is usually selected in commercial breeding programs. A major gene ( D/ d) has been described for this character located on linkage group 5 of peach, where the low acid character is determined by the dominant D allele. In this paper, we analyze a collection of 231 varieties and 542 offspring to identify diagnostic markers for this character. The CPPCT040 single sequence repeat (SSR) is known to be tightly linked to D. We found that one of its alleles (193) is diagnostic for the subacid character and identified with high probability individuals with low acidity (titratable acidity <5.5 mg/l). The region around CPPCT040 was explored using 13 DNA fragments for a total of 5,297 bp, covering a length of 70.4 kbp of the peach genome. The sequenced fragments detected 19 single nucleotide polymorphisms (SNPs) and five indels. All subacid individuals shared a large haplotype (>24 kb) around CPPCT040, a region with higher than average SNPs between acid and subacid varieties. The CPPCT040 marker plus one of the SNPs identified (DH875) were used to genotype a collection of 542 seedlings, from different crosses expected to segregate for this character, which were phenotyped by tasting the fruit in the field. Data provided by both markers were always consistent and only 24 plants (4 %) did not fit the expectations. These markers and others that can be obtained from the haplotype identified can be readily used for marker-assisted selection in peach breeding. [ABSTRACT FROM AUTHOR]

Highlights: [•] Blooming time, fruit type and breeding programme influence the response to low temperature among cultivars. [•] The greater the frost damage the greater was the proportion of flowers showing symptoms in hardier tissues. [•] Tolerance response to low temperature showed important variability among peach cultivars. [•] FT10, FT50 and FT90 values differ among peach cultivars. [ABSTRACT FROM AUTHOR]

Abstract: Nowadays more than 70 active peach breeding programmes are developed around the world, all of them, regardless of country, with their specific objectives. Nevertheless, there is no currently available information comparing different peach cultivars based in their origin in terms of agronomic performance and fruit quality under Mediterranean climatic conditions. For this reason, we evaluated the influence of fruit type, origin (continent and breeding programme) and cultivar on adaptability, production and susceptibility to powdery mildew. A study was carried out on 112 cultivars at the IRTA-Experimental Station of Lleida (Spain) during the 2009 and 2011 seasons in which melting peach cultivars presented better agronomical performance than nectarine, nonmelting peach and flat peach cultivars. Comparing continents, USA versus Europe, in terms of fruit type, melting peach and nectarine cultivars from Europe were best adapted to Mediterranean conditions. According to origin by fruit type, melting peach cultivars from Monteaux-Caillet, ASF, Zaiger and A. Minguzzi showed the best agronomical performance. In the case of nectarine, the ASF, PSB and Bradford breeding programmes provided the most interesting cultivars. The fact that there are only a few breeding programmes for flat peaches makes them all the more interesting to producers. In most of the traits studied important variability among cultivars was recorded, either within the same breeding programme. In spite of these results, the cultivars in each breeding programme were clearly different; this explains why producers tend to adopt the strategy of choosing cultivars from different breeding programmes. [Copyright &y& Elsevier]

• The studied apple germplasm showed a high biodiversity. • Higher contents of TPC were found in local accessions than in the commercial ones. • Climate affects the antioxidant and metabolite profiles of apple accessions. • Precipitation and solar radiation increased bioactive compounds in apple accessions. • Accessions, year and climate were the main factors affecting metabolite profiles. Apples are highly appreciated in terms of flavor, nutritional and health-promoting compounds and are associated with a reduced risk to develop age-related and chronic diseases. In this study, 155 accessions of Malus x domestica Borkh from the apple germplasm collection, located at the Experimental Station of Aula Dei in NE Spain, were analyzed during five consecutive years (2014–2018). Basic fruit quality traits including soluble solids content (SSC), titratable acidity (TA) and the ratio SSC/TA (ripening index - RI) were obtained. In addition, biochemical compounds such as total phenolics content (TPC), flavonoids (TFC), vitamin C (Ascorbic acid - AsA) and relative antioxidant capacity (RAC) were determined. Statistical analysis was used to determine differences in trait values among accessions and years. The well adapted local accessions showed, in general, higher average content of antioxidants and RAC compared with the foreign and commercial ones. A multivariate model was fitted with the accessions and climate features of each year as independent variables. A cluster analysis was then performed on the model coefficients space to classify the 155 accessions within five groups. The cluster analysis showed that foreign cultivars (those not originating from Spain) were concentrated in two groups while local accessions could not be segregated and had very different profiles. Furthermore, they increased the concentration of bioactive compounds tended to decrease with higher temperatures, while increased with higher solar radiation. Statistical analyses emphasized differences between groups and highlighted accessions and climate as main factors affecting metabolite profiles and fruit characteristics. [ABSTRACT FROM AUTHOR]