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First tentative attempt at crossing

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  • First tentative attempt at crossing

    Today I've made my first tentative attempt to cross pea varieties - just two. Beginning cautiously!

    Both used Sugar Magnolia as the male and one used Jaune de Madras as the female and the other Opal Creek.

    Please forgive my plodding thoughts on the likely outcome - assuming they take, as not easy in a minor gale, but will try again if not .

    So this is what I'm thinking the outcome should be:

    Opal Creek x Sugar Magnolia

    F1 - flower colour, wild purple
    F2 - flower colour 3/4 purple, 1/4 white

    F1 - pod colour, purple
    F2 - pod colour, 3/4 purple, 1/4 yellow

    F1- pod type, sugar snap
    F2 - pod type, sugar snap

    Jaune de Madras x Sugar Magnolia

    Flower colour and pod colour as above

    Pod type - ??

    Have I understood the simplest basics of Mendelian ratios etc?
    And as Jaune de Madras is a mangetout and Sugar Magnolia is a sugar snap is there a way of anticipating the pod type? Recessive genes etc? I realise I can do some more homework using the JIC website - and will- but would appreciate a human input as well!

  • #2
    Opal Creek x SM. Yes apart from pod colour. The F1 pod colour which should be all purple may not be (experience) due to the problems with loss of purple genes. F2 pod colour likewise far less purple than expected, green, yellow and if very lucky some red too. Interesting colours may emerge like greenish yellow pods, or ice green pods and so on. Many will be somewhat blotchy rather than true full colours. Pod type should all be snap. All very edible, all hopefully sweet as both parents are sweet.

    There may be notable pod size differences. It really is not all as cut and dried as genetics would suggest. But all are edible. Good on you and good luck.
    Last edited by Galina; 24-05-2020, 08:22.

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    • Galina
      Galina commented
      Editing a comment
      Jaune de M x SM. As above. However, surprisingly, I had some shelling types with my first cross with Golden Sweet x Schweizer Riesen and I don't know which parent it was that is not 'true' mangetout. If JdM and Golden Sweet are the same and if the partial mangetout only inheritance comes from JdM, then not all pods resulting from that cross may be mangetout or snap. There could be shelling pods. Theoretically a quarter would be snap pods, the rest mangetout (with the above caution about shelling pods). Colours as above.

      Again what you see on the ground is what counts, not what genetics suggests. However the chances for a red mangetout or a red snap are there. Red mangetout is far more likely with this cross, but you have the first cross for theoretically guaranteed snaps (unless something unexpected happens to that cross and it will not all be snaps). You will see what you get in real life in the F2 and later, and that is the only new variety that counts.
      Last edited by Galina; 24-05-2020, 08:17.

    • Galina
      Galina commented
      Editing a comment
      You will see a lot of green and blotchy green or purple or red, because for full purple you need both pu and pur genes, more often only one is inherited. There is also loss of purple for other reasons, like anthocyanin is not always available to the plant in the quantities that would be needed. It fades during hot weather, late in the season or for any other reasons. By extension the same applies to red which also needs pu and pur.

      In both crosses the rarest recessive is a red snap variety emerging. More likely in the first cross. In the second cross a mangetout is 75% likely (theoretically, what you get on the ground may be different) and a snap at 25% percent. To be statistically significant and confirm the Mendellian ratios, you would need to grow a significant number. But hey, there is beginner's luck and who knows you may get that rare 1 in 64 with a small planting, if you grow the right F2 seeds. For now just make the crosses and label. And good luck.
      Last edited by Galina; 24-05-2020, 08:02.

    • Galina
      Galina commented
      Editing a comment
      Last comment. If for some reason the cross has not taken with SM pollen, because the yellow varieties were already self pollinated, then the F1 will be yellow, a good check.

  • #3
    That's brilliantly helpful. Thank you.

    I've just realised in fact that I was forgetting that Jaune de Madras has the wild purple type flower colour so presumably that will dominate in flower production but pod colour for both should be as you suggest in your first message above. Lots to look forward to!

    Rebsie Fairholm suggests that sometimes a partial pollination happens so you might get stunted pods forming with undeveloped peas or just a couple of peas. Does that often happen in your experience?

    Comment


    • Galina
      Galina commented
      Editing a comment
      Yes and no. With sowing under protection and planting out one F1 is as good as many unless you can devote a huge growing area to one cross. You only need one seed, but more are better for safety if there is a mishap with the one. The real number you need are the F2 seeds coming from that F1. And the number of F3 seeds. If you are looking for a rare feature, say a red snap from your second cross, then you would need a lot of F2 and F3 seeds, but if you are only looking say for any red podded pea, then fewer are needed. However few or many you have, there is always luck involved to get just that right one seed. Which of course could still show itself in the F3 or more rarely the F4 generation. It takes 6 or even more generation for a new variety to be reasonably stable.

    • Galina
      Galina commented
      Editing a comment
      The more important reason to make more than one cross (unless you are way more skillful than I am, which is entirely possible), is that by no means every handpollinated cross 'takes'. They can be fickle. Make 3 to get one that actually grows into a pea for me is the real reason to make several crosses where possible. I have had 3 out of 3 and I have also had a complete no-show. But the more you make, the more will take.

    • Jang
      Jang commented
      Editing a comment
      Yes, it was to guard against dud results in the crossing, and the more than likely human error. I've noticed my carefully tied piece of thread had already fallen off. Room for much error I'm sure.

      But thank you also for emphasising the needs of the different generations so clearly.

  • #4
    My first tentative attempts at crossing have been harvested. Shiraz came late to the party so some Shiraz crosses included. Very small numbers of peas in some cases but enough to be interesting I hope. Pleased to have some result at least from each cross attempted.

    As the seed from my Opal Creek x Sugar Magnolia is perfectly round where the mother seed is more dimpled, might that imply that the cross was successful?
    Click image for larger version

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    • Galina
      Galina commented
      Editing a comment
      I haven't despite best endevours something had to give - well quite a lot actually. But growing out past crosses has given me a red snap and a new yellow snap. So I am not complaining in the least.

    • Galina
      Galina commented
      Editing a comment
      Not so odd. Think of squashes or courgettes. Whichever variety courgette pollinates yours, you will end up with true to type courgettes if you started off with true breeding seeds. Because the outer fruit and the seed coat are maternal material, only the germ inside the seed coat is filial material. Your crossed pea looked like the mother, the seed coat is maternal and the germ inside the seed coat is the only F1 material, just like with cucurbita. The F1 should be totally uniform (apart from factors like problems with purple in peas), but the seeds inside those F1 peas next year will be different, giving a first indication of the diversity to expect in your F2 generation.

    • Jang
      Jang commented
      Editing a comment
      Yes, sorry I wasn’t clear. What I meant to say was that it was odd that mine weren’t like the mother given that they should have been like the mother. My Opal Creek crosses didn’t look like their mother in fact. The Opal Creek seeds are quite shrunken. So I’m not at all sure what has happened there.

  • #5
    As these are very precious F1 seeds, I store mine in paper bags to avoid any chance that they might not have been fully dry. If you call me paranoid, I will not object . Alternatively a few grains of rice into those baggies serves the same purpose as they take up any last hint of moisture. Seed coat is generally speaking maternal material. Can you remember which was the pollen donor and which was the maternal plant for your crosses?

    And very well done Jan.

    Comment


    • Jang
      Jang commented
      Editing a comment
      Thanks for the tip. I was a little worried about possible dampness but also felt I wanted them safe and delight in being able to see them! I’ll certainly follow the rice advice.
      In each cross I’ve put the maternal plant first. I remember a discussion of which was considered usual practice and hoped I’d remembered that that’s the convention - but happy to be corrected.
      Last edited by Jang; 16-08-2020, 04:43.

    • Galina
      Galina commented
      Editing a comment
      Another way of getting small bags of desiccant is to ask nicely in a shoe shop or a handbag shop, as there are often these tiny bags in shoe boxes. I have swapped a box of choccie bikkies for the staff for a box of small desiccant sachets at the local shoe shop.

  • #6
    I do understand wanting to be able to see those F1 treasures and dream!

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