Hybrids: Cross-breeding
Welcome to a special edition of Succulent Science Sunday! This is actually Part 2 of the entire Succulent Family series. You can read the first one on phylogenies (family trees) here.
If you're interested in other succulent genetics stuff, be sure to check out my other posts! In order:
Phylogeny: Who's related to who? (Echeveria vs. Sedum)
Hybrids: Cross-breeding YOU ARE HERE
Variegation Genetics: (recessive trait, endosymbiotic theory)
Hybridization: Ploidy (compatible ploidy and hybrids)
This week we will be exploring the science of cross-breeding your own hybrid succulents! This is a part-science, part-practical guide to help you on your way to making new original succulent babies.
Famous Hybrids
These hybrids are given interesting names, designed to pique your intrigue. They may be given classic scientific binomial names, or they may be called "parent 1 x parent 2". You can learn more about taxonomic groups here.
Graptoveria ‘Opalina’ = Graptopetalum amethystinum x Echeveria colorata
Echeveria "Perle von Nurnberg" = Echeveria gibbiflora var. "metallica" x Echeveria elegans
Echeveria "Morning Beauty" or Echeveria subsessilis= Echeveria cante x Echeveria shaviana
Echeveria "Lola" = Echeveria lilacina x Echeveria derenbergii
Echeveria "Fred Ives" = Graptopetalum paraguayense x Echeveria gibbiflora
Echeveria "Black Prince" = Echeveria affinis x Echeveria shaviana
Perle von Nurnberg, Echeveria Morning Beauty, and Echeveria Lola are the top sellers list at Mountain Crest Gardens!
Who breeds them?
Anyone with access to flowering succulents! Or even succulent pollen.
Here are some famous breeders of selected succulents above:
Richard Graessner is from Perleberg, Germany. In 1930, the famous succulent grower created the famous Echeveria "Perle von Nurnberg."
Kelly Griffin is a succulent breeder for Altman Plants. He specializes in aloe, agave, and dudleyas. He crossbred Echeveria laui and Echeveria lilacina to make Echeveria "Moondust"
Albert Baynes, was a founding member of England's "National Cactus & Succulent Society" in 1846. He created Echeveria "Fred Ives" by breeding Graptopetalum paraguayense and Echeveria gibbiflora.
Renee O'Connell also works for Altman Plants. She created Echeveria "Neon Beakers" as well as some of the more well-known and beautiful succs on the market. A fuller listing of her succulent hybrids are found here.
Dick Wright has been breeding succs since 1958! He's based in California and sells his own creations via his website. He crossbred Echeveria lilacina and Echeveria derenbergii to make Echeveria "Lola"-- a personal favorite of mine.
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| Above: My Echeveria Lola. Isn't she pretty? |
You may remember the name of Johann Gregor Mendel, the pea plant guy, who brought us our concept of modern genetics. He was an Austrian monk who lived in the 1800s and taught, among other things, botany. He used pea plants as a model system because they were easy to work with. While today we know of many complicated circumstances involving genetics, these pea plants were pretty tame and allowed us a sneak peak into the world of genetics. I'll be focusing on monohybrid (single trait) crosses for the purposes of this blog.
In the pea plant study, Mendel hand-pollinated a tall pea plant and a short pea plant. He expected their offspring to be all medium plants, and for the generation made of that first generation to be also all medium plants. What actually happened was far weirder. The first generation after the parent generation were all tall plants! And breeding all of the first generation plants together yielded 3 tall plants and 1 short plant. What was going on?
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| Image modified from "Mendel seven characters," by Mariana Ruiz Villareal (public domain). |
Vocabulary
Alleles are forms of a gene. There are recessive alleles and dominant alleles.
Dominant alleles are stronger genes that are expressed if there is a hybrid. (Have capital letters: R)
Recessive alleles will not be expressed if there is a hybrid. (Have lowercase letters: r)
Genotype is a gene combination. For example, a trait like "red leaves" could hypothetically be RR
Phenotype is the physical trait you see, for example "red leaves"
Punnet Squares
Let's use Mendel's pea plant example above. Tall is encoded by R, a dominant allele. Short is encoded by r, a recessive allele. The genotype for parent 1 is RR and the genotype for parent 2 is rr. Now let's make hybrid babies! The first generation comes out all Rr, and therefore all tall because R is the dominant allele that is stronger than little r. How do I know this [besides the fact that Mendel actually counted all the pea plants]? The punnet square!
Tall plant RR x Short plant rr. Parents are placed on the top and side of the box. Offspring are in the squares of the box. Each square is determined by listing the allele of its row and of its column.
Then, he took the offspring and crossbred those together:
As you can see, RR, Rr, Rr are all Tall, while rr is the one short plant! This is just what Mendel saw!
Non-Mendelian Genetics
Please be aware though, that there are many, many exceptions to simple, Mendelian genetics. Things like skin, hair, and eye color can fall within a range, rather than the either-or picture Mendelian genetics describes. There are also other traits which skip generations, or traits that depend on a combination things...
In Terms of Succulents?
Color is dominant to green
Colored tips are dominant to non-tipped
Size of the rosette is a multi-gene trait, so the babies will range widely.
For the succulents I've seen, leaf color is incorporated and leaf shape is compromised. I think the rule of thumb is just try it. If it doesn't work, it doesn't work, but you might end up with some pretty interesting creations in the meantime.
Here, you can see what traits of the parents ended up in the hybrid:
Hybrid: Echeveria "Perle von Nurnberg"
Parents: Echeveria elegans x Echeveria gibbiflora var. "metallica"
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| Above: Echeveria elegans (left) and Echeveria gibbiflora var "Metallica" Photos via wikipedia.org and lapshin.org |
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| My own Perle von Nurnberg |
Cross-Breeding Candidates for the Beginner
Graptopetalum, Echeveria, and Sedum readily crossbreed with each other, creating some names you might have heard of.Graptopetalum x Echeveria = Graptoveria
Sedum x Echeveria = Sedeveria
Graptopetalum x Sedum = Graptosedum
After reading Part 1 of this two part series, you may begin to understand why it's all a little bit like succulent incest. As scientists have unraveled the DNA of our beloved succulents, we've found that taxonomic names don't always match up to who's actually related to who. In short, if you're a beginner breeder and you have any combination of the above, you're probably in good shape. Sempervivums also are pretty promiscuous with themselves.
Since we all don't have DNA kits in our homes, it may be useless to even bring up the fact that some are diploids and others are polyploids. For a more in-depth discussion on what this means, read my post here. [To be honest, I'm not a geneticist and this is totally out of my league! If any master breeder wants to get in touch and enlighten me, pretty pretty please, get in touch!]
Storing Pollen in 4 Easy Steps
One of the more practical problems you may have is how to cross-pollinate when your blooms aren't blooming at the same time. Pollen cannot be stored long-term for the average breeder, who can't afford the fancy equipment at larger companies, however, I've put together four easy steps to storing pollen for up to 5 years:
1. Get some small, snap-cap, micro-centrifuge tubes. They sell them in bulk on Amazon for about $10.
2. You will want to collect the pollen on a paintbrush, put the pollen into the centrifuge tube (open) and then stick it into a closed container (like a mason jar or food container) with a desiccant like silica gel packs or rice.
3. Let dry out for 24 hours.
4. Snap that cap shut, and grab a medicine bottle or small glass jar. Fill the glass jar 1/2 way with sand. Stick in your well sealed centrifuge tube. Fill the rest of the way with sand. Shut the jar. Voila!
That should last you 3-5 years, good enough until one of your other succulents make a flower. Caution: Do not freeze seeds! They will be ruined! Store in an envelope and place in a dry place.
Mechanics: Birds and the Bees
A DIY video for the artistic breeder. Even professional breeders use artist's paintbrushes!
There's also a part 2 to this video that helps you see what the flowers should look like afterwards.
How seeds form in the flower
Pollination is the act of the pollen (which acts like sperm) reaching the stigma.
In a plant, the female part of the flower is the carpel and this contains the stigma, style, and ovary. The ovary contains the female gametes.
The male part is called the stamen and has the anther and filament. The pollen comes from the anther. The pollen encloses the male gametes.
Sterile Hybrids
Don't be surprised if you hybrids are sterile. They can still be propagated by leaves. Some hybrids are sterile, some are not. It's sort of like the liger, the sterile hybrid of lions and tigers. Or the mule, the sterile hybrid of the horse and donkey. It all has to do with matching up chromosomes, and as we've already discovered, chromosomes and succulents are a tricky thing to track. For a more in-depth discussion, click my post here.
Thanks for reading this week's Succulent Science Sunday! If you want to read more about variegation genetics, click here. If you want to learn from Master Breeders, click here. Leave a comment below or fill out the contact form if you have an idea for an upcoming installment. Hit subscribe for more sciency-succulent fun!
BONUS:
Speaking of hybrids...reverse mermaids, anyone? Julie Benbassat (JBASS) has created a an original collection of reverse mermaids in her new, illustrated book, The Merms of May. It is a handbound 5 x 5 pamphlet. Great for all ages who love odd things. Buy her one-of-a-kind book on her website, here.
Julie Benbassat is a freelance illustrator educated at the Rhode Island School of Design. She has illustration experience in children's books, editorial magazines, world building and character design. For prints of some of her work, go to her shop, or if you would like to contact her about freelance work, email her at JBASS.ILLUS@gmail.com
Julie Benbassat • JBASS
References:
https://altmanplants.com/intergeneric-hybrid-succulents/
http://youngsgardenshop.com/blog/hybridizing-sempervivum/
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