Segregation and culling micro woolly blue tomato project

My micro dwarf woolly blue tomato breeding project is making more progress.  There are still a few years before this project will be completed, but I think it is time for another update.  

I have written earlier blog posts on micro tomatoes, and high anthocyanin (true black) tomatoes, and woolly leaf tomatoes.  

I wrote a previous blog post on my attempt to cross a micro dwarf tomato with an angora leaf tomato, in the hopes of breeding a micro woolly tomato with blue/black fruit.  I also wrote an update on progress and the F1 plant.  

Tomato seedling - woolly foliage 

I successfully made the cross between the micro tomato and the woolly leaf high anthocyanin tomato, and I grew out an F1 plant.  I saved a lot of seed from the F1, and planted some of that seed this winter/spring.  I planted a lot of F2 seeds so that I could cull really hard and hopefully get what I am hoping for reasonably quickly.  My original goal was to produce a micro dwarf woolly leaf plant with blue/black fruit.  

The F2 seedlings will display a lot of genetic diversity.  Some were easy to cull from a very young age, while other genes won't be displayed until later so the seedlings needed growing out for longer.  

The first cull was pretty simple:  

Some plants were tall, they were culled quickly as they are easy to see from a young age.

Some plants will be dwarf, and others will be micro dwarf.  It can be difficult to tell these apart when they are seedlings.  These will be kept until they grow larger as I would hate to cull a vigorous micro dwarf.  Also if I have too few keepers I may want to keep some of these dwarf lines for back crossing and produce micro dwarfs from them.  

Out of the remaining dwarf and micro-dwarf plants the next cull was also reasonably simple:  

Some plants have regular leaf, they were quickly culled as they are simple to see from a young age.

Some plants will be heterozygous for woolly leaf and are kind of woolly, others will be homozygous for woolly genes and will have very fluffy leaf.  All of these will be grown out until later.  Again I don't want to kill off any heterozygous woolly leaf plants as I may want to keep these lines to produce true homozygous angora leaf lines.

Tomato seedlings - needs more culling

The dwarf and micro dwarf woolly leaf plants are going to be grown out until larger.  I plan to keep every micro dwarf woolly leaf tomato plant.

These may have different fruit colour, some may be red, others yellow, and I would kind of like some of each.  As well as this they could have various amounts of anthocyanin, ranging from none to very dark black.  It is difficult to tell at this young age so I will have to grow out a number of plants.

I planted dozens of seeds, and have a bit left over for another try next year if this doesn't work out.  At this stage there are several plants that appear to be micro dwarf and woolly.  I plan to keep them and hopefully save seed from them.  Even if none of them are what I am after I may be able to cross them with something that has the missing genes and eventually develop what I am wanting.

One of these F2 seedlings in particular appears to be high in anthocyanin as the leaves are displaying a high degree of purple colouration.  It is too early to know for sure, but it fills me with hope.

Several potential keepers, others need culling

While my goal was to produce a micro dwarf woolly leaf plant with blue/black fruit, I may or may not achieve that this year.  Even if I do achieve that, I still have a number of generations to grow out before the line will be stabilised.  

I am happy to say that micro tomatoes have short generational times, and I can usually get 2 or 3 generations per year (sometimes even 4).  I am also working a lot with recessive and partly recessive genes.  This means that stabilising lines of micro dwarf tomatoes may take a lot of generations, but this should hopefully be completed in a small number of years.  

Working with recessive (and partially recessive) genes also means that in the early stages when the line is not yet stable they should retain all of the traits that I want to see in each future generation.  It shows progress, which is good to help keep up the motivation to bother breeding things like this.

Things have progressed a little since I took the photos, plants have grown, I have culled more plants, there are still some unknowns, and I have a few really promising fuzzy little tomato plants.  I can hardly wait to see what these grow out to be.

At this stage I plan to grow out every micro dwarf with woolly foliage, and start a few different lines from them.  I may or may not grow out and collect seed from any of the other promising plants.  If all goes well I will have several different fruit colours in my micro woolly lines before too long.  

I really want a high anthocyanin micro woolly line, and I may be able to achieve that on both red fruit as well as yellow fruit.  Only time will tell.