Breeding the Tomato Micro-Tom Model System for Ornamental Value

Abstract

Taking advantage of its small size (8 cm tall) and short life cycle (70 days), the ornamental tomato cv. Micro-Tom (MT) was proposed as a model system for tomato genetics. Ever since, MT has been used for large scale mutagenesis and the introgression of allelic variation already known in other cultivars and tomato wild species. Such new genotypes could also be used to improve its value as an ornamental. Here we report the introgression, through successive backcrosses, of various mutations affecting fruit color and morphology into the MT background. Various true type genotypes combining reduced plant size and fruit color variation were obtained upon introgression of the mutations Del, old gold (og), Beta (B), green stripe (gs), pink fruit (y), yellow flesh (r), tangerine (t), apricot (at) and green flesh (gf). Four mutations affecting fruit format, i.e. ovate (o), fasciated (f), sun and fs8.1, were also introgressed into MT. These mutations and the combination of them greatly extends the value of MT as an ornamental and introduces the possibility of exploring the large diversity of induced and natural mutations in tomato for this purpose.

Genetic Mapping of green-stripe in Tomato

“…The striped-fruit phenotype is an attractive coloration pattern widely used in tomato breeding. Irregular and longitudinal green stripes are visible on the epidermis of immature and mature green-striped tomato fruit (Zamir et al, 1984;Farinha et al, 2009). Longitudinal stripes appear on many fruits such as watermelons, melons, pumpkins, pears, and squashes (Zhai et al, 2019).…”