Browse Articles

Article|01 Jun 2021|OPEN
Multi-year analyses on three populations reveal the first stable QTLs for tolerance to rain-induced fruit cracking in sweet cherry (Prunus avium L.)
Philippe Letourmy1, José Antonio Campoy2, Camille Branchereau1, Svetoslav Malchev3, Teresa Barreneche1, Elisabeth Dirlewanger1 & José Quero-Garcia4
1CIRAD, UPR AIDA, University of Montpellier, TA B-115/02, Avenue Agropolis, 34398 Montpellier Cedex 5, France
2Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg, 50289 Cologne, Germany
3Fruit Growing Institute – Plovdiv, 12 Ostromila Str., 4004 Plovdiv, Bulgaria
4INRAE, Biologie du Fruit et Pathologie, Université de Bordeaux, UMR 1332, F-33140 Villenave d’Ornon, France

Horticulture Research 8,
Article number: 136 (2021)
doi: 10.1038/hortres.2021.136
Views: 156

Received: 30 Nov 2020
Revised: 16 Apr 2021
Accepted: 26 Apr 2021
Published online: 01 Jun 2021

Abstract

Rain-induced fruit cracking is a major problem in sweet cherry cultivation. Basic research has been conducted to disentangle the physiological and mechanistic bases of this complex phenomenon, whereas genetic studies have lagged behind. The objective of this work was to disentangle the genetic determinism of rain-induced fruit cracking. We hypothesized that a large genetic variation would be revealed, by visual field observations conducted on mapping populations derived from well-contrasted cultivars for cracking tolerance. Three populations were evaluated over 7–8 years by estimating the proportion of cracked fruits for each genotype at maturity, at three different areas of the sweet cherry fruit: pistillar end, stem end, and fruit side. An original approach was adopted to integrate, within simple linear models, covariates potentially related to cracking, such as rainfall accumulation before harvest, fruit weight, and firmness. We found the first stable quantitative trait loci (QTLs) for cherry fruit cracking, explaining percentages of phenotypic variance above 20%, for each of these three types of cracking tolerance, in different linkage groups, confirming the high complexity of this trait. For these and other QTLs, further analyses suggested the existence of at least two-linked QTLs in each linkage group, some of which showed confidence intervals close to 5 cM. These promising results open the possibility of developing marker-assisted selection strategies to select cracking-tolerant sweet cherry cultivars. Further studies are needed to confirm the stability of the reported QTLs over different genetic backgrounds and environments and to narrow down the QTL confidence intervals, allowing the exploration of underlying candidate genes.