Pitch is how high or low we hear a sound to be. If the frequency is higher, the pitch is higher. The unit of frequency is hertz. Ghz, or gigahertz, also can be used to measure frequencies.
The L.esculentum complex consists of six other species which are relatively easy to cross with the common tomato. All species in this group are diploid (2n = 2x = 24). Most (except L. hirsutum f. typicum and some L. pennellii) are self-compatible.
The poor taste and lack of sugar in modern garden and commercial tomato varieties resulted from breeding tomatoes to ripen uniformly red. This change occurred after discovery of a mutant u phenotype in the mid 20th century that ripened uniformly.