View Single Post
Old December 29, 2012   #8
maf
Tomatovillian™
 
maf's Avatar
 
Join Date: Jun 2010
Location: England
Posts: 515
Default

This is a subject that I have researched over the last couple of years and I have found no documented evidence for "black" tomatoes in North America (or England) before the 1950's. The earliest description of gf, the gene responsible for dark tomatoes is by E.A. Kerr in the 1956 report of the Tomato Genetics Cooperative:
Quote:
Kerr, E.A. Green flesh, gf

The fruit of a late-blight resistant tomato obtained
from the Central Experimental Farm, Ottawa, as Philippine #2 is much fasciated
and, when ripe, is a dirty purplish brown color. This ripe fruit color is
recessive in the F1 and gives monogenic F2 segregation ratios. The fruit
color is caused by a failure of the chlorophyll to break down when the
lycopene is formed... Hence both chlorophyll and lycopene are present in the
mature fruit. Since r r fruits do not form lycopene, fruits of r r gf gf
genotype have a green-color when mature. Preliminary tests indicate that
gf may be linked with al in group VI and also with the type of fasciation
found in Philippine #2-:-
From: http://tgc.ifas.ufl.edu/vol6/vol6.pdf (Warning: slow loading pdf file.)

The research in the article Dar linked is what sparked my original interest in this topic. There are five different alleles of gf so the "black" phenotype originated independantly on five unique occasions, possibly in different parts of the world. If you look at the list of cultivars by allele it seems that gf2, gf3 and gf5 can be classed as alleles derived from Russian cultivars, while gf(1) is in American and West European cultivars that can be associated with the Philippine #2 origin, and gf4 is a mixed bag as far as place of origin is concerned.

So where did the first "black" tomato occur? The earliest proven and documented record is in 1950's USA from material imported from the Philippines. Any of the other alleles could have originated before or after the one first described, and it is possible that other very similar mutations have occured previously but were not followed up by the grower, and thus died out, because they did not meet his expectation of what a tomato should look like.
maf is offline   Reply With Quote