conference schedule and program with abstracts - Horticulture ...

O-22
Identification of table grapes genes related to seedlessness, berry size and GAresponsiveness
by functional genomics
P. Hinrichsen* 1 , M. González-Agüero 1,2 , M. Pinto 1,3 , C. Uquillas 1 , N. Mejía 1 , A . Riquelme 3 , T.
Fichet 3 , A. Aravena 2 , A.M. Almeida 4 , A. Orellana 2,4 , and C. Muñoz 1
1 Instituto de Investigaciones Agropecuarias (INIA), CRI La Platina, Chile; 2 The Plant Cell
Biotechnology Millennium Nucleus (PCB-MN), Santiago, Chile; 3 Universidad de Chile,
Santiago, Chile; 4 Universidad Andrés Bello, Santiago, Chile
*Corresponding author: phinrichsen@inia.cl
A table grape breeding program was initiated 15 years ago by the Chilean Institute of Agriculture
Research, INIA. This Program is now part of the ‘Biofrutales Consortium’, a private-public
partnership. The breeding approach of the Program has been to increasingly incorporate the use
of biotechnological tools to improve the efficiency and precision with which parents and
segregants are selected. The first step in this approach was to build a framework linkage map
based on ca. 120 co-dominant SSR markers and the subsequent identification of QTLs for traits
such as seedlessness and berry size. Later on, physical, genetic and in silico maps were
integrated and about 20 candidate genes were identified. Within the major QTL for seedlessness
and berry size, the AGL-11 gene was located on LG18 and found responsible for a large fraction
of the variance for both traits. Two other candidate genes, SPY and PMEI, were associated to a
secondary QTLs and characterized by RT-PCR in different genetic backgrounds. Details of this
association will be presented on a separate paper. Currently, segregants from a ‘Ruby Seedless’ x
‘Thompson Seedless’ cross, which exhibit contrasting phenotypes for seed and berry size, are
being used to study the transcriptome of berries at different stages of development (fruit set, 2-4
mm ∅ and 6-8 mm ∅), treated or not with gibberellic acid. This population is under analysis by
hybridization (Combimatrix) or by massive cDNA sequencing (Illumina). Also the
proteome is being analyzed in 2-D gels associated to mass spectrometry. Those genes
consistently detected by two or more of these approaches, will be individually screened by RT-
PCR to determine their expression level. Also, a position on the reference map will be proposed
by looking for co-locations of these genes and the secondary QTLs. The possible association
between the phenotypic expression and the allelic variation will be analysed in search of markers
that could be used as a selection tool in INIA’s Table Grape Breeding Program.
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