In Vitro Polyploidization in Solanum lycopersicum Mill. ‘Santa Cruz Kada Gigante'

Abstract

Solanum lycopersicum Mill. is a model plant for biological approaches and includes accessions with great agronomic relevance, such as the ‘Santa Cruz Kada Gigante'. For development of new S. lycopersicum accessions, in vitro tissue culture has proved relevant, contributing to the establishment of germplasm banks and breeding programs. In spite of the vast amount of tissue culture research already carried out in S. lycopersicum, in vitro polyploidization is still emerging. Thus, this study aimed to induce polyploid plantlets from ‘Santa Cruz Kada Gigante' from shoot tip explants. This accession presented 2n=2x=24 chromosomes and 2C=2.00 picograms of nuclear DNA. Hence, no preexisting variation was identified, and ‘Santa Cruz Kada Gigante' was considered appropriate for in vitro polyploidization. This procedure provided tetraploid (4x) and mixoploid (2x/4x and 2x/4x/8x) plantlets, which were identified by flow cytometry (FCM) and multiplied in vitro. Based on these results, the tissue culture procedure provided polyploid ‘Santa Cruz Kada Gigante' plantlets, which represent a new source of variability for breeding programs of S. lycopersicum.