Welcome to the Micro Multi-Flora project! Here is some information to guide you when participating in this project, things to look for, and what the goals are. If you have any questions, please feel free to ask!
Goal
The goal with this project is to develop multiple varieties of Micro Tomatoes which exhibit what we are calling a "multi-flora" flowering habit. In scientific literature, this is commonly called a "compound inflorescence" and is likely associated with the gene "s". I will walk through more of this below. When we say "multiple varieties" - we mean a good diversity in fruit types (shape, color, taste, size) and also in leaf and growth habit. We want to find and develop these varieties into at least an F7 or F8 generation so that they are fairly stable with very few off-types.
As this is a micro project, the target plant size is up to about 18", with 12" or less being primary focus.
Inflorescences
Meriam-Webster defines "Inflorescence" as:
For our purposes, we will simplify this down to simply mean "the flowering appendage". Sometimes we might refer to this a "flower truss" and you might see some refer to it as "tress". All of these refer to the same thing, the flower cluster of the tomato.
What we call a "normal" inflorescence on a tomato is a flower truss that has multiple flowers, typically in a "zig zag" pattern. The number of flowers varies by cultivar, but 3-12 flowers probably describe a typical number, with a few cultivars perhaps having a few more - such as in some indeterminate cherry types.
Compound Inflorescences
In varieties which exhibit compound inflorescences, the flower truss will repeatedly branch until finally each branch terminates in a flower. This usually results in a truss that blooms a hundred or more flowers. To the gardener growing one of these, it might appear as an explosion of flowers, perhaps resembling a fireworks display.
In the image below (click to enlarge), picture "B" and its two insets demonstrate a "normal" tomato inflorescence. Picture "D" demonstrates a "compound" tomato inflorescence. Notice how each the truss initially branches, and then branches again, and again, and again until finally terminating.
Note that the image also has a variation of the "s" gene (picture E). The "s-multiflora" allele encodes for flower trusses with cauliflower like masses on the truss along with flowers. We are not pursuing this variation, and if one is found - it should not be considered a part of this project.
Shades of Grey
Given the above description and image - one might come to the conclusion that a plant either "is" or "is not" multi-flora. Genetically, perhaps that might be true - either it has the "s" mutation or it does not. However, what we've noticed so far is that there appears to some variation in the "multi-flora-ness", where a plant might tend towards being multi-flora and have some level of compound inflorescences, but not a massive explosion of flowers. Perhaps it only has 30 or 40 flowers on a truss.
Part of this project will be to observe and identify how more or fewer flowers impact the growth and fruit set of the plant. We want to identify if a micro tomato can set fruit on a majority of a hundred or two hundred flowers. Is 30 or 40 flowers more ideal and does it result in higher total production?
Multi-Flora Inputs
At this time, the primary input of the Multi-Flora gene/component is from the MMF variety that Dan Follett helped Chris Kafer work on, which originated from the cross of (Red Robin x Rose Quartz Multiflora). We can, and likely should, introduce other MF inputs as there are other MF indeterminates available on the commercial market - and also accessions within GRIN or TGRC which also have this characteristic.
The allele of "s" exhibited by Rose Quartz appears to be an independent mutation that is different than the classic "s" mutation.
Scientific Literature and References
These are some indicators which help track the timing and development of the compound inflorescences, and are recommended to track to help differentiate observed phenotypes. These are above and beyond any normal data points, such as height, DTM, fruit characteristics, etc.
Goal
The goal with this project is to develop multiple varieties of Micro Tomatoes which exhibit what we are calling a "multi-flora" flowering habit. In scientific literature, this is commonly called a "compound inflorescence" and is likely associated with the gene "s". I will walk through more of this below. When we say "multiple varieties" - we mean a good diversity in fruit types (shape, color, taste, size) and also in leaf and growth habit. We want to find and develop these varieties into at least an F7 or F8 generation so that they are fairly stable with very few off-types.
As this is a micro project, the target plant size is up to about 18", with 12" or less being primary focus.
Inflorescences
Meriam-Webster defines "Inflorescence" as:
- 1a: the mode of development and arrangement of flowers on an axis
- b: a floral axis with its appendages
- also : a flower cluster
- 2: the budding and unfolding of blossoms : FLOWERING
For our purposes, we will simplify this down to simply mean "the flowering appendage". Sometimes we might refer to this a "flower truss" and you might see some refer to it as "tress". All of these refer to the same thing, the flower cluster of the tomato.
What we call a "normal" inflorescence on a tomato is a flower truss that has multiple flowers, typically in a "zig zag" pattern. The number of flowers varies by cultivar, but 3-12 flowers probably describe a typical number, with a few cultivars perhaps having a few more - such as in some indeterminate cherry types.
Compound Inflorescences
In varieties which exhibit compound inflorescences, the flower truss will repeatedly branch until finally each branch terminates in a flower. This usually results in a truss that blooms a hundred or more flowers. To the gardener growing one of these, it might appear as an explosion of flowers, perhaps resembling a fireworks display.
In the image below (click to enlarge), picture "B" and its two insets demonstrate a "normal" tomato inflorescence. Picture "D" demonstrates a "compound" tomato inflorescence. Notice how each the truss initially branches, and then branches again, and again, and again until finally terminating.
Note that the image also has a variation of the "s" gene (picture E). The "s-multiflora" allele encodes for flower trusses with cauliflower like masses on the truss along with flowers. We are not pursuing this variation, and if one is found - it should not be considered a part of this project.
Shades of Grey
Given the above description and image - one might come to the conclusion that a plant either "is" or "is not" multi-flora. Genetically, perhaps that might be true - either it has the "s" mutation or it does not. However, what we've noticed so far is that there appears to some variation in the "multi-flora-ness", where a plant might tend towards being multi-flora and have some level of compound inflorescences, but not a massive explosion of flowers. Perhaps it only has 30 or 40 flowers on a truss.
Part of this project will be to observe and identify how more or fewer flowers impact the growth and fruit set of the plant. We want to identify if a micro tomato can set fruit on a majority of a hundred or two hundred flowers. Is 30 or 40 flowers more ideal and does it result in higher total production?
Multi-Flora Inputs
At this time, the primary input of the Multi-Flora gene/component is from the MMF variety that Dan Follett helped Chris Kafer work on, which originated from the cross of (Red Robin x Rose Quartz Multiflora). We can, and likely should, introduce other MF inputs as there are other MF indeterminates available on the commercial market - and also accessions within GRIN or TGRC which also have this characteristic.
The allele of "s" exhibited by Rose Quartz appears to be an independent mutation that is different than the classic "s" mutation.
Scientific Literature and References
- The Making of a Compound Inflorescence in Tomato and Related Nightshades
- Characterization of tomato (Solanum lycopersicum L.) mutants affected in their flowering time and in the morphogenesis of their reproductive structure
- Tomato Flower Anatomy
- Chris Kafer blog
- Rose Quartz Multiflora at WTS
These are some indicators which help track the timing and development of the compound inflorescences, and are recommended to track to help differentiate observed phenotypes. These are above and beyond any normal data points, such as height, DTM, fruit characteristics, etc.
- Days to first exhibit of compound inflorescence
- Days to first bloom of compound inflorescence
- Number of compound inflorescences
- Approximate fruit set on compound inflorescences (estimated percentage)
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