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Article|01 Nov 2021|OPEN
Genetic and phenotypic analyses reveal major quantitative loci associated to fruit size and shape traits in a non-flat peach collection (P. persica L. Batsch)
Irina Baccichet1, Remo Chiozzotto1, Cristian Silvestri2, Laura Rossini1, Daniele Bassi1 & Marco Cirilli1,
1Università degli Studi di Milano - DiSAA, Milano, Italy
2Università degli Studi della Tuscia - DAFNE, Viterbo, Italy

Horticulture Research 8,
Article number: 232 (2021)
doi: 10.1038/hortres.2021.232
Views: 43

Received: 20 Apr 2021
Revised: 23 Jul 2021
Accepted: 27 Jul 2021
Published online: 01 Nov 2021

Abstract

Fruit size and shape are critical agronomical and pomological attributes and prime targets in peach breeding programs. Apart from the flat peach type, a Mendelian trait well-characterized at the genetic level, ample diversity of fruit size and shapes is present across peach germplasms. Nevertheless, knowledge of the underlying genomic loci remains limited. In this work, fruit size and shape were assessed in a collection of non-flat peach accessions and selections, under controlled fruit load conditions. The architecture of these traits was then dissected by combining association and linkage mapping, revealing a major locus on the proximal end of chromosome 6 (qSHL/Fs6.1) explaining a large proportion of phenotypic variability for longitudinal shape and also affecting fruit size. A second major locus for fruit longitudinal shape (qSHL5.1), probably also affecting fruit size, was found co-localizing at locus G, suggesting pleiotropic effects of peach/nectarine traits. An additional QTL for fruit longitudinal shape (qSHL6.2) was identified in the distal end of chromosome 6 in a cross with an ornamental double-flower peach and co-localized with the Di2 locus, controlling flower morphology. Besides assisting breeding activities, knowledge of loci controlling fruit size and shape paves the way for more in-depth studies aimed at the identification of underlying genetic variant(s).