Andrew’s Pea Breeding Tips [2017]

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As homage to my older blog post about pea breeding information, which is an archived copy of my currently defunct website, i wanted to share a few tips and a pea breeding technique that i invented that helps increase the rate of pea crossbreeding success and produces a higher seed per pod ratio than standard “paintbrush” or “scalpel” crossbreeding techniques.

pea1b

Standard Pea Crossbreeding technique is one that i call the “paintbrush method”. It works, i guess. But i think I’ve found a better way. In the paintbrush or scalpel crossbreeding method you basically find the two pea flowers you want to use. First you select a closed immature flower as the female parent that you then use with a small pair of scissors (lefthand curved embroidery scissors work well for this) to remove all the pollen anthers before they have a chance to release mature pollen and self pollinate. Second, you then take an open mature pea flower to use as the male flower and use a paintbrush or scalpel to collect pollen and transfer it to the receptive style/stigma.

lefty scissor curved close

Andrew’s Pea Crossing Method:

My method is a bit odd looking at first, but in my experience it works MUCH better. On average from what i can tell you usually get about 1-2 peas per pod with the “paintbrush method”. No more than 4. With my method i’d say you get on average of¬†4-5 peas per pod, with the potential of a whole pod 6-8 peas depending on your variety. So i’d say I’ve at least doubled the success rate, maybe even tripled it.

tweezer

First, i’d say get rid of that embroidery scissor. While it works, i find that a combination of pulling off the outer petals with your hands and using a small flat beveled or angled pair of tweezers works fantastically well. Get yourself a pair of tweezers like these. They may be referred to as “eyebrow tweezers”.

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Second, find yourself an immature pea flower to use as the female parent. Rip off all the outer petals and remove the immature anthers before it can self-pollinate. Third, find yourself an open mature flower for the male parent. Just cut or rip the whole flower off of the plant, we will need the whole thing. Fourth, use your tweezers to make a small opening in the bottom of the keel petal. Followed by slipping the flower used as the male over the stigma and style of the flower used as the female parent, making sure that the stigma/style gets covered in pollen at the top of the keel petal shown in the picture above. There is a small reservoir of pollen up there that makes for plenty of pollen to go around. Finally, leave this flower covering on there as long as possible. Sometimes they fall off, it helps to try pollinating the flower again during the next few days if this happens.

Why is this technique more successful?

Well, for me i think it’s a combination of things. First and most importantly it serves as a hood or covering for the flower to keep pollen from drying out or being washed away in the rain. In my climate the air can be quite dry and the high altitude with intense sunlight tends to wick away moisture quite easily. These tiny pea styles are quite delicate and seem to dry out so quickly that they can dry out before pollen has been able to set seed. Second, it provides a LOT of pollen over that whole style. I could be wrong, but i suspect that each of the receptive seed ovules mature at different times. If this is true, then it requires enough good pollen to be available over several days for each seed to be pollinated and grow. And finally, it just seems to mimic everything about how a pea flower would naturally self pollinate. Sometimes it’s best to just imitate nature as sometimes nature knows best.

How do you know what age of pea flower to use?

Good question. Here is a good illustration that should help. You need to catch a pea flower used as the female parent very very early actually. The pea flower second from the left is just about perfect because it is big enough to use but young enough it should not have released pollen and selfed yet. The open flower on the far right is about right for using as a pollen donor. If the pollen is too old or not enough, select a similar one that is slightly younger or try one that looks like the third one from the left.

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And that’s it. If you have any thoughts, please leave a comment. I hope you find it interesting and helpful. Happy Tinkering! ūüôā

http://daughterofthesoil.blogspot.com/2007/05/how-to-breed-your-own-garden-peas.html

8. Pea Breeding by Earl T. Gritton

http://daughterofthesoil.blogspot.com/2006/06/how-to-hybridise-garden-peas.html

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Following in Mendel’s Footsteps

…and discovering how interesting pea breeding can actually be…

Google’s logo showing a dihybrid cross, but failing to follow the law of independent assortment (yellow pods & yellow seeds are not linked), and also failing to show that yellow seeds are dominant. But, it does show the 3:1 ratio of green:yellow pods in the F2 generation.

After noticing that Google’s logo today was in honor of Gregor Mendel’s 189th Birthday, I decided to make a post about pea breeding. On first thought pea breeding doesn’t sound all that interesting. Even to people who are interested in plant breeding in general. I myself thought that Mendel had already worked with all the interesting traits found in peas out there, but i have found that i was wrong. I’m starting to find that the traits Mendel worked with are actually very neat in person, and the ones he didn’t know about are even more interesting.

The Google logo itself is actually a visual representation of Mendel’s experiment of crossing yellow podded peas (recessive) with that of green podded peas (dominant), but it also shows his other experiment of crossing yellow seeds with green seeds. Unfortunately¬†it looks like Google’s logo is not following the law of independent assortment and is showing linkage between yellow pods and yellow seeds, which is incorrect. Yellow seeds are actually dominant, so Google fails in that regard. But, even so it illustrates the ratio of 3:1. In other words, in the F2 generation 3/4 of the offspring will be green-podded and 1/4 yellow podded.

yellow-poded constricted pea pod
yellow-podded pea also with the constricted pod gene (Golden Sweet)

The picture above shows a variety called “Golden Sweet” which remarkably has both the rare yellow-podded gene, but also the gene for constricted pods. After growing this variety for the first time here in my own garden, i can see why Mendel was so fascinated with pea traits at the time. I personally think his experiments were directly inspired by this unique variety of pea, which is suspected to have become close to extinction in Europe and the rest of the world, until it was accidentally¬†rediscovered recently in a collection of seeds from India. It certainly is a pea with some interesting genetics.

breeding peas

I’ve only just started to experiment with crossing peas this year. While it sounds like it would be hard, it’s actually fairly easy. But, it really does help to have a tiny pair of scissors instead of an exacto knife or scalpel. The only hard part is that pea flowers are self fertile and self¬†pollinating¬†by nature, and you must catch the flowers very early to be able to cut off the immature pollen so you can use pollen from another plant. I really don’t know how Mendel did that in his day in age, but i applaud the man. Here are two links to pea breeding on Rebsie Fairholm’s blog.

How to breed your own garden peas
How to hybridise garden peas 

The Results of Mendel's F1 crosses for Seven Characters in Pea Plants
Mendel worked with several different pea traits, and documented at least seven of those. Yellow-podded vs Green-podded, Yellow-seeded vs Green-seeded, Inflated Pods vs Constricted pods, Round seeds vs Wrinkled seeds, Tall vs Dwarf, flower position, and flower color.
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Several Pea Traits I’m Currently Researching (I’m actually researching more than seven)
Here is a neat illustrated table of the various pea traits that I’m currently researching. It shows a more accurate color of the purple pea flowers which is known as Bicolour Purple. It also shows Salmon-Flowered, Terminal flowers (fasciated umbellatum-type peas), red-seeded peas, purple-seeded peas, purple podded peas, red-podded peas, Tendril-less peas, and Hyper-Tendril peas. In reality i am studying more than seven traits, but i put the table together as sort of an ode to Mendel.
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Purple-podded snow pea 'Midnight Snow'
‘Midnight Snow’ snow pea (purple-podded mangetout / edible-podded pea)
Some of the most interesting pea traits are the ones that i don’t think Mendel even knew existed. Purple-podded seems to be one of the ones Mendel never seems to have written about. But it is widely reported that the purple-podded varieties of peas originated from the Capuchin monks in the Netherlands.
The Unusual Parsley Pea
The Unusual Parsley Pea
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Hyper-Tendril peas! (aka. semi-leafless peas)
Hyper-Tendril peas! (aka. semi-leafless peas)

Alan Kapuler of Oregon discovered a while back that if you outcross a pea called “Parsley Pea” which has an insane amount of leaflets on it’s tendrils, that you can get a pea that has hyper-tendrils and has twice the amount of tendrils and doesn’t require a trellis to support themselves.

Rebsie Fairholm's famous red-podded pea
Rebsie Fairholm’s famous red-podded pea

Rebsie Fairholm from the U.K. discovered just a few years ago (2008) that when you cross a purple-podded pea with a yellow-podded pea you get a red-podded pea! How awesome is that!

Pea, Biskopens
Biskopens (rare red-seeded pea). Photo by Soren.

 

I’m currently trying collect lots of pea varieties with rare and interesting traits, but one that is uniquely rare though is one called Biskopens. It is the only pea that i know of that has red seeds! Yeah, it’s a red-seeded pea!

Pea, Purple Passion
Purple Passion (rare purple-seeded pea). Photo by Soren.

This is a very rare variety i was lucky (and surprised) to get in a recent trade. I really look forward to growing out this variety next spring. Supposedly it also has purple pods. I have no idea what it’s origin is. I’m curious if it’s the same gene as the red Biskopens pea, but perhaps with a green seed underneath so maybe this one comes out purple? I’m just speculating at this point.

Salmon-flowered pea
Salmon-flowered pea

If you are still interested in all of this, then please feel free to visit my pea_breeding webpage to find out more¬†detailed information about pea genetics and about Mendel’s work with peas (as well as¬† and Rebsie’s red-podded pea). Or my recently updated webpage about the seven-ish unusual pea traits that i’m currently studying at http://biolumo.com/garden/peas.html.