Dark Green Tomato Project

nicollas · October 14, 2023

I've launched a collaborative tomato breeding project this year, so i'll present it in this first message :

Here is the message i posted in the OSSI forum to introduce the project :

Here is a fun project i decided to open to other breeders/growers to try to collectively find a dark green colored tomato.

Here is the description i've made of it. If anyone is interested let me know. I'm in Europe. Link to the doc which may have a better formatting.

Dark Green Tomato Collaborative Breeding Project

Project goal

Discover tomatoes with dark colored fruits (dark green, dark purple, dark brown), by growing collaboratively a lot of F2 plants .

Target color (right fruits) :

Origin of the project

A spontaneous mutation was discovered in the cultivar Manalpa, leading to an accumulation of chlorophyll before maturation (see above picture). The involved gene is a recessive gene name dg (dark green) or hp-2 (hight pigment). The accumulated chlorophyll is then converted during maturation, giving fruits of a lit bit more intense red color.

Goal of the project is to combine the dg gene with other genes that helps to keep the chlorophyll during maturation, thus giving a dark color, and even better to combine it also with genes stopping other pigment colors to appears to keep a dark green colored tomato.

In 2011, I crossed the accession LA3005 containing the mutant gene dg with the cultivar Captain Lucky.

During 2022, I cultivated some F1 plants. All plant had red colored fruits, which was expected because all involved genes are recessive.

2023 is the exciting year ! Growing F2 generation should allow for the recombination of recessive genes giving the desired phenotype.

A bit of Genetic

The project is based of three categories of genes :

The recessive gene leading to accumulation of chlorophyll, dg.
The recessive gene blocking the degradation of chlorophyll during maturation, gf.The recessive gene (partially) blocking the creation of the lycopène red pigment, ry.

The dark green color is thus a combination of three recessive genes : dg + gf + ry.

Knowing the number and nature of involved genes, one can compute the number of plants that need to be grown in order to have a given percent of chance to succeed.

To have a 90% chance of finding a dark green colored fruited tomato, one has to grow ~150 plants of tomato.

This statistic is valid even spread among different people. Thus if 6 people grow each 25 plants, there is 90% chance of success that at least one of the grower will discover the dark green tomato.

How the project works

What you’ll receive

Based on your capacity to grow a number of plants protected from late blight, you’ll receive a number of seeds each of F2 generation.

Your contribution to the project

You commit to grow in good faith the number of plants we agreed at the start of the project.
In the case where you discover a dark colored tomato plant among your plants, you commit to share some seeds with at least a few folks contributing to the project, with the goal to spread seeds among participants and outside of the project.

What to expect ?

The following table list the chances of obtaining a dark green tomato plant (left), or more broadly a dark colored tomato (right).

Nb of plants / % chance to find a dark green tomato

25 / 32%
50 / 54%
75 / 69%
100 / 79%
125 / 86%
150 / 90%

Once a dark green tomato is found, jackpot ! The recessive character of all three involved gene guarantee that all further generations will be dark colored (excluding spontaneous mutation or accidental cross).

Of course not all characteristics of the plant will be fixed in the F3 generation. The plant will need a few more years to be fully stabilized. Meanwhile, those F3 seeds will still be precious to share among other breeders to start a dark green tomato revolution !

What next ?

What about crossing these dark green tomato with blue (anthocyanin) tomatoes ? The accumulation of chlorophyll could lead to very dark blue tomatoes. What about adding stripes ? Or developing a ‘real’ dark green tomato crossing the dark green tomato with green tomatoes like green zebra ?

October 14, 2023	#1
nicollas Tomatovillian™ Join Date: Sep 2014 Location: France Posts: 142	Dark Green Tomato Project I've launched a collaborative tomato breeding project this year, so i'll present it in this first message : Here is the message i posted in the OSSI forum to introduce the project : Here is a fun project i decided to open to other breeders/growers to try to collectively find a dark green colored tomato. Here is the description i've made of it. If anyone is interested let me know. I'm in Europe. Link to the doc which may have a better formatting. Dark Green Tomato Collaborative Breeding Project Project goal Discover tomatoes with dark colored fruits (dark green, dark purple, dark brown), by growing collaboratively a lot of F2 plants . Target color (right fruits) : Origin of the project A spontaneous mutation was discovered in the cultivar Manalpa, leading to an accumulation of chlorophyll before maturation (see above picture). The involved gene is a recessive gene name dg (dark green) or hp-2 (hight pigment). The accumulated chlorophyll is then converted during maturation, giving fruits of a lit bit more intense red color. Goal of the project is to combine the dg gene with other genes that helps to keep the chlorophyll during maturation, thus giving a dark color, and even better to combine it also with genes stopping other pigment colors to appears to keep a dark green colored tomato. In 2011, I crossed the accession LA3005 containing the mutant gene dg with the cultivar Captain Lucky. During 2022, I cultivated some F1 plants. All plant had red colored fruits, which was expected because all involved genes are recessive. 2023 is the exciting year ! Growing F2 generation should allow for the recombination of recessive genes giving the desired phenotype. A bit of Genetic The project is based of three categories of genes : The recessive gene leading to accumulation of chlorophyll, dg. The recessive gene blocking the degradation of chlorophyll during maturation, gf.The recessive gene (partially) blocking the creation of the lycopène red pigment, ry. The dark green color is thus a combination of three recessive genes : dg + gf + ry. Knowing the number and nature of involved genes, one can compute the number of plants that need to be grown in order to have a given percent of chance to succeed. To have a 90% chance of finding a dark green colored fruited tomato, one has to grow ~150 plants of tomato. This statistic is valid even spread among different people. Thus if 6 people grow each 25 plants, there is 90% chance of success that at least one of the grower will discover the dark green tomato. How the project works What you’ll receive Based on your capacity to grow a number of plants protected from late blight, you’ll receive a number of seeds each of F2 generation. Your contribution to the project You commit to grow in good faith the number of plants we agreed at the start of the project. In the case where you discover a dark colored tomato plant among your plants, you commit to share some seeds with at least a few folks contributing to the project, with the goal to spread seeds among participants and outside of the project. What to expect ? The following table list the chances of obtaining a dark green tomato plant (left), or more broadly a dark colored tomato (right). Nb of plants / % chance to find a dark green tomato 25 / 32% 50 / 54% 75 / 69% 100 / 79% 125 / 86% 150 / 90% Once a dark green tomato is found, jackpot ! The recessive character of all three involved gene guarantee that all further generations will be dark colored (excluding spontaneous mutation or accidental cross). Of course not all characteristics of the plant will be fixed in the F3 generation. The plant will need a few more years to be fully stabilized. Meanwhile, those F3 seeds will still be precious to share among other breeders to start a dark green tomato revolution ! What next ? What about crossing these dark green tomato with blue (anthocyanin) tomatoes ? The accumulation of chlorophyll could lead to very dark blue tomatoes. What about adding stripes ? Or developing a ‘real’ dark green tomato crossing the dark green tomato with green tomatoes like green zebra ?