Using SNP arrays to leverage historic data sets for improved prediction accuracy and estimation of GxE of fruit maturity in sweet cherry (abstract)

Publishe

Whole-Genome Analysis of Diversity and SNP-Major Gene Association in Peach Germplasm

Peach was domesticated in China more than four millennia ago and from there it spread world-wide. Since the middle of the last century, peach breeding programs have been very dynamic generating hundreds of new commercial varieties, however, in most cases such varieties derive from a limited collection of parental lines (founders). This is one reason for the observed low levels of variability of the commercial gene pool, implying that knowledge of the extent and distribution of genetic variability in peach is critical to allow the choice of adequate parents to confer enhanced productivity, adaptation and quality to improved varieties. With this aim we genotyped 1,580 peach accessions (including a few closely related Prunus species) maintained and phenotyped in five germplasm collections (four European and one Chinese) with the International Peach SNP Consortium 9K SNP peach array. The study of population structure revealed the subdivision of the panel in three main populations, one mainly made up of Occidental varieties from breeding programs (POP1OCB), one of Occidental landraces (POP2OCT) and the third of Oriental accessions (POP3OR). Analysis of linkage disequilibrium (LD) identified differential patterns of genome-wide LD blocks in each of the populations. Phenotypic data for seven monogenic traits were integrated in a genome-wide association study (GWAS). The significantly associated SNPs were always in the regions predicted by linkage analysis, forming haplotypes of markers. These diagnostic haplotypes could be used for marker-assisted selection (MAS) in modern breeding programs

Genetic diversity studies in sweet cherry

International audienc

Harmonisation of phenology stages and selected cherry cultivars as bioindicators for climate change

Perennial fruit crops phenology such as cherry is an ideal bio-indicator of climate change due to their long-lasting features, in particular, dates of flower opening and full bloom. This implies i) the use of several generations of cherry trees/ orchards and ii) the use of the same original cherry cultivars, which existed as bearing trees and were replanted after the orchard had been grubbed. A comparison of available definitions of phenological stages in cherry previously used independently throughout Europe showed overlaps and shortcomings; hence, harmonisation was reached in this respect in the COST Cherry FA 1104 working group 2 (cherry phenology and climate change) based largely on the acceptance of the BBCH scale. This contribution presents the agreed phenology stages in both visual and wording evidence. Similarly, this contribution presents the agreed cultivars to be monitored in future for phenology and climate change effects for harmonisation. For sweet cherry, this EU-wide harmonisation includes 'Burlat', 'Cristobalina' and 'Rita' as early, 'Stella' and 'Van' as medium flowering and 'Sweetheart', 'Regina' and 'Bigarreau Noire de Meched/Germersdorfer' for late flowering cultivars for climate change effects. For sour cherry, this harmonisation resulted in 'Meteor korai' and 'Anglaise Hative' for early flowering, 'Chrisana Pandy' and 'Erdibotermo' for medium flowering and 'Schattemorelle', 'Iiva, Ujfehrtoifurtos (Balaton)' for late flowering

Efficient monitoring of phenology in chestnuts

Chestnuts (Castanea spp.) are ecologically and economically important forest and fruit trees. They are cultivated for their nutritious nuts. To select varieties to be cultivated in chestnut orchards, their phenology needs to be considered. In this work, we adapt the international BBCH system to chestnuts by building on an existing phenological scale used in some European countries for these species. The proposed BBCH scale uses eight of the ten principal growth stages for fruit trees and secondary growth stages that are specific to chestnut trees. We tested it by monitoring chestnut trees phenology during three growing seasons, illustrating its suitability for high-throughput phenotyping studies. Overall, the approach used, despite its inherent limitations, is straightforward, accessible and flexible, allowing particularly precise description of the complex flowering phenology of these trees

Advances in breeding of chestnuts

UMR BFP - Equipe A3