UMH 1200, a Breeding Line within the Muchamiel Tomato Type Resistant to Three Viruses

Abstract

Muchamiel is a tomato landrace that is very popular in southeastern Spain as a result of its organoleptic fruit quality. Fruits of the Muchamiel cultivars have a melting texture and mild flavor, are large in size (180 g to 300 g), flattened, and strongly ribbed. However, this landrace is severely endangered and at risk of extinction as a result of its high susceptibility to several viruses such as those caused by the Tomato mosaic virus (ToMV), Tomato spotted wilt virus (TSWV), and Tomato yellow curl virus (TYLCV) (Pico et al., 2002). To introgress genetic resistances to ToMV, TSWV, and TYLCV into the Muchamiel landrace, a breeding program has been carried out over the last 10 years at Miguel Hernandez University (Spain). Breeding line UMH 1200 is the first release produced by this breeding program. UMH 1200 has medium-sized fruits (150 to 190 g) and organoleptic characteristics similar to those of the original landrace. This homozygous breeding line suffers from a yield penalty compared with the original landrace, which is variable depending on the growing conditions, but its tolerance/resistance to ToMV, TSWV, and TYLCV has been demonstrated in several field and greenhouse trials.