Introgression of Genomic Regions from a Wild Tomato Species into an Argentinean Cultivar Improve Fruit Quality Traits.

PEREIRA DA COSTA JAVIER H.; RODRÍGUEZ GUSTAVO R.; ZORZOLI ROXANA; LUCIANI MARIANELA D.

San Diego, California

Conferencia; International Plant & Animal Genome XXV; 2017

Fruit quality in tomato defines the cultivar choice by producers and even more by consumers. Wild species carry favorable alleles to improve fruit quality traits such as color, texture, shelf life and sugar content. The aim of this work is to improve fruit quality of Caimanta, an Argentinean cultivar, by an introgression process of genomic regions from the wild accession LA722 of S. pimpinellifolium. The backcrosses were assisted by SSR as DNA molecular markers. Twenty near isogenic lines (NILs) were developed after three or four rounds of backcrosses. To assay the association between genomic regions and the phenotypic traits five plants of each NIL were compared with Caimanta by t-Student test. The evaluated fruit quality traits were: fruit firmness, color (a/b index and L), diameter and fruit height, shape index (height/diameter), weight, fruit shelf life, locule number, pericarp thinness, soluble solid content, pH and titratable acidity. Every genomic regions introgressed into the Caimanta genome showed significant effect on fruit traits. Particularly, genomic regions in chromosomes 5, 7, 8, and 9 (in four different NILs) had effect on color, firmness and fruit shelf life. Moreover, introgression on chromosomes 2, 3, 8, and 9 had significant effects on fruit size. All NILs showed more firmness than Caimanta, suggesting that several regions spanning through the genome would control this trait. We conclude that the introgression of genomic regions from wild species into this cultivated genome allowed us to improve fruit quality traits and to obtain some NILs as putative new cultivars.