Just went and checked the green seed from drying pods off my Melting Mammoth that I sowed a few days ago - one of the peas has already sprouted! Most pleased - I have just picked the fully developed pods from my first crosses in the first few days of November, so am thinking of sowing some tomorrow or in a couple of days. Have put the pods in the dehydrator this morning - on very low -  to hasten the process, but I'm not sure that I should have...
If I sow tomorrow or the next day, I should have emerging plants before I go away 2nd week of December, then leave them on the watering system in big pots to grow until I get back. Cut a few weeks out of the cycle.

I've spent the weekend musing on strategies now that I've actually got some material to work on.

Of my early crosses I got full pods from the first 5 crosses or so (the later pods are very incompletely filled, so that material will probably have to wait until late summer for sowing - I can't afford to take risks with it). These were hangover crosses - being a bit under the weather, I used recessive pollen on dominant mothers, so I won't be able to tell from the F1 plants whether my crosses were successful or if the seeds are from self pollinations. I also wrote down the names wrong citing Oregon Snap as the pollen donor - except there is no Oregon Snap parent - and a few days later when I re-read the labels, I couldn't remember whether I had used Sugar Snap Bush or Oregon Spring pollen. At least they are both white flowered,multi flowered, powdery resistant, dwarf, edible podded - just that Sugar Snap Bush also carries the n gene for thick pods.

I've got 3 full pods of these mislabelled crosses, so i could potentially have 18 or so seeds. I can probably afford to experiment with half, say 9 seeds.

However, the Lost Seed Co variety of purple podded (PP(LSC)) only developed 4 full pods on each plant. At say 6 peas per pod, that's only 24 F2 seeds per F1 plant - not a lot for a grow out. But I could get ~ 500 seeds at the F3, enough for a substantial grow out of say half, with half put aside to delve into if nothing turns up in the first F3 batch. So this week I might sow half the seed from these first crosses (which were 'wrong way' crosses), 12 weeks to seed harvest (that's what the first generation took) takes me through to the end of February, sow all the F2s to have them flowering at the end of April, with seed for sowing at the start of May. If I get about 12 seeds from each of these summer grown peas (Rebsie suggests seed number and quality is poor from hot weather plants), I could potentially have ~100 F2 seeds for late February sowing.

The F2s will have segregated and various traits will have been expressed, so I might have some stable recessive lines - dwarfism or powdery resistance or uncoloured leaf axils to select from. I'm not going to be able to tell about the low fibre pod characteristics without sacrificing some pods, which I'm not willing to do. Since I'm after purple podded snows, I would put the seed from the uncoloured leaf axil plants to one side, and grow out the rest (depending on number) - purple axil colouration seems to be linked tightly with A the anthocyanin gene which I need for purple pods - at least according to Mendel. Since it is dominant, if the plants were carrying even one copy (heterozygous) it would be expressed, so no purple axil, no A.


I've also crossed Purple Podded (Select Organics) with Yellow Podded, looking for a red pod. For a red podded I need purple pods (A_Pu_Pur_) over yellow pods gpgp. Yellow Podded already carries A, so all the progeny of the crosses will be AA. So to get a red podded in the F2 generation I need Pu_Pur_gpgp, the odds of which are 3/4 X 3/4 X 1/4 = 9/64 or about 1 in 7 - if the genes are independent.

So I might also sow some of the PP(SO)XGP F1s this week - since the outcome is not really a huge target for my program, the seed is a bit expendable, and it might be encouraging to see how it segregates next autumn. And I might just turn up something interesting...

Ditto with my Yellow Snow crosses, trying to turn up a half decent yellow snow pea. I've crossed Golden Podded with Oregon Spring and Delta Louisa, both dwarf double flowered snows. I should have a few seeds to spare, so I might try a few out.
(I'll come back and put some pics in this post a bit later)

Cross pollination aid for middle-aged eyesight

I've been wandering out early mornings with my first cup of coffee for the last month or so, seeking flower buds for crossing purposes. But in the dim 6 am light, a certain wine induced bleariness, and my aging eyes, emasculating tiny buds - which have been getting tinier as the season warms up - has necessitated some visual augmentation.
I could have purchased some neat fold down magnifiers, but they are a bit steep in price, and I procrastinated, and didn't order them, two weeks delivery for online purchases, blah blah blah, so this morning, frustrated, I dug out a couple of hand lenses, an old peaked cap, and tried to get a self supporting magnifier that left both hands free for delicate surgery.

Wasn't working...then i remembered my old bike helmet, which I had rigged up with an eye level rear vision mirror - before these things became standard attachments in the eighties - which dates me and the helmet. A bit of foam from a shrink wrap vege tray to protect the mirror, a bulldog clip, and I'm set...

Aberrant Angela's Blue - musings on heterozygosity

I'm growing four or five plants of each of my purple podded parent lines, one of which is Angela's Blue. However, one of the plants seems to not be carrying its full complement of purple podded genes. As discussed elsewhere, I need A to turn on anthocyanin production, and Pu and Pur to express this colour in the pods. I've been wondering what would happen if I only got one of Pu or Pur as a result of one of my crosses. This aberrant plant of Angela's might indicate the result. It shows a dappled purple colouration.

A developing pod on Aberrant Angela's Blue

The plant has only two pods, so it might not be a good plant to choose as a pollen donor, but both pods show this patterning. So how might this have arisen?
A, Pu and Pur, the three genes needed for purple podding are dominant. Whoever bred Angela's would have had to select for purple podded phenotype from their original cross. This means the plants they selected from would have had to be carrying A, Pu and Pur. But you can't tell if the plant has one copy of the dominant gene (heterozygous) or double copies (homozygous) unless you grow out lots of the progeny. My guess is the original parent was heterzygous, was grown out for a number of generations until the breeder thought it was homozygous for all three genes, but lurking in the population from which the seed was collected was a plant which was heterozygous for either Pu or Pur.



This is what a purple podded is supossed to look like:

More genes: flower number

Peas that carry multiple pods per node are considered more desirable - although some reports suggest that rather than increasing yield, it may reduce it - the plant puts extra resources into flower and pod production, depleting the overall performance of the plant. I haven't done any tests, but I like the idea of compact plants producing lots of pods, so I'm thinking of trying for pultiple flowers.
This is controlled by two recessive genes, fn, and fna.

They are interactive -fn or fna alone gives two flowers, fn fna together gives two or more flowers. However, the genes may be incompletely expressed; flower number is also influenced by environmental conditions.

#1836, a tall multiflowered pea from Greece, showing repeated double flowering nodes

Some of my multi-flower lines alternate single flowered nodes with double flowered nodes - Melting Mammoth for example. But some of my Jovian accessions, Salahi, a white flowered semi dwarf fibrepodded pea from Nepal, or #1836 a purple flowered from Greece, for example has almost all double flowers - perhaps there is some gene interaction going on, that partially overrides the environmental limitations on the other varieties.

It would be nice to get both fn and fna - I will probably need to cross a number of multiflowered lines to see if I have both genes...

Some genes of note 2: stem length.

 Personally, I prefer medium height veges - I'm a bit over all the staking and tying up required for monster vegetables - towering 9 foot tomatoes and beans that are out of reach all require extra work in the garden - I prefer a neat plant head high or less. Where folks are limited for space I can see the point, or for boasting rights, but the structure needed to hold up a huge fully loaded tomato plant for example is considerable. While I am a bit limited for space, the defining limitation in my central Victorian garden is water, followed by nutrients, then sunlight. If I want to optimise variety, then smaller plants with modest requirements are what I need. Less energy put into construction means more time and energy for other stuff. So I would like to breed dwarfism into my peas.
My go-to genetic resource, the JI database has some interesting info on stem length in peas.

 Genes coh, cona, and cot all shorten internodes. The database is silent on how these interact.

Long internodes

le shortens internodes and gives a zigzag stem pattern
lh gives a 60-70% reduction in internode length
lka gives reduced internodes and "reduced branching and peduncle length, stem banding"
lkb and lkc also reduce internode length, with other physiological changes.
lm reduces internodes but effects  roots.
lw gives "reduced internode length by 50%. Delayed flowering especially under short days"
na is "compact dwarf with extremely shortened internodes"

Short internodes on Delta Louisa - perhaps a hint of zig zag?

So, I wonder which of these genes is regulating internode length in Delta Louisa, Oreson Spring, Sugar Snap Bush, and Sahali, all of which exhibit short or shortish stems...

Some other genes of note: disease resistance

In addition to the genes for colour, some of which I've discussed in a previous post, there are a number of genes of home horticultural importance.
Foremost are probably the genes for powdery mildew resistance. There are two genes, both of which confer resistance to Erysiphe polygoni the organism responsible for powdery.
They are known as er-1 and er-2, both are recessive. The JI database notes of er-2 "Resistance broken under controlled growth conditions so not as durable as resistance conferred by er-1".
Being recessives sahould make them easy to fix, but since the only phenotypic expression is disease resistance, it is hard to distinguish whether they are present or not until E.polygoni strikes, and then how might one distinguish between them?

I have at least one line that has at least one of these genes - Delta Louisa is powdery resistant. And by the looks of my recent observations it appears that Oregon Spring, another dwarf snow pea line is also resistant. On the left of the photo is three purple podded lines - PP Select Organics, Angela's Blue, and PP Lost Seed Co, along with Swiss Giant, which all seem to be succeptible. On the right of the bed is Delta Louisa and Oregon Spring, both of which seem resistant. One line from the Jovan accessions (my research centre acquisitions) was an unknown Powdery Resistant Snow Pea, a survivor of the centre's Powdery chamber of death. It has been reluctant to germinate - of 5 seeds sown in Septenber only one survived - a subsequent resowing of 4 seeds yielded nothing. So I'm hoping for a good crop of seed from the one remaining plant. However, a bit bleary the other morning, I absent-mindedly emasculated one of its two flowers - shock horror! I've crossed it to a purple podded, so hopefully it takes and at least I will get something useful out of the error.

In search of A, the anthocyanin gene

To get reds and purples in peas, the starting gene is A, a dominant gene that controls anthocyanin production, responsible for many of the blue purple and red colours in plants. Other genes turn on the expression of this in various parts of the plant. And some genes turn it off, even when the plant carries A.
Why is this important? To get a stable line of coloured peas, having A contributed by both parents means you don't have to search for it in the offspring - every child plant will carry AA. So when I cross a Purple Podded with a snow pea, if the snow pea carries A, the numbers of crossed offspring i need to grow in subsequent generations is reduced. I only have to search for the other genes. This will influence the grow out strategies in future seasons.



A normal indicator of A is purple or red colouration somewhere in the plant - the leaf axils, the flowers, the sepals, or even the seed - if they are red or purple or brown, then the plant carries A. For example, my Golden Podded pea has yellow pedicels and sepals, but I can tell it carries A because it has purple leaf axils and petals.


 But there are lots of genes that influence colour of flowers and other bits, some acting alone, others in combination with other genes. A bit of a search on the John Innes database showed the following possibilities, amongst others


Genes am1 and am2 inhibit colour expression in flowers even if A is present.

b gives rose pink flowers and an effect on axil and seed coat colours, and axil pigmentation is reduced from purple to red. For example, the Golden Podded above looks a bit reddish to me - must compare with some others I've got growing.

Cit gives a citrus yellow flower - interacts with gene Cm to give "a light dull ocher with faint salmon hue."
cfg gives greenish flowers, and rub gives brick red wings on the flower.

So lots of material to play with out there.
 Unfortunately, all of my lines so far have either purple or white flowers - will have a close look over the next few days to see if there are any of these aberations lurking in the patch.