Breeding for Late Blight resistance (potatoes)

[jayb]

I've been thinking about this for a few years now but not really done anything; it’s really easy to get side tracked with bright colours, different shapes and tastes etc. But with LB being a devastating annual ‘event’ here, it’s a direction I want to take. There has been some superb breeding work by the real deal pro's, something to look up to and in a small way aim for.

The last few years I’ve grown a couple of varieties that have good resistance and it is amazing to see how they are either not touched by LB as it sweeps through the rest of the plot or you see brown marks on the leaves to indicate its presence but it never fully develops. I've noticed that spores don’t seem to be produced and the plants remain mostly unaffected and just carry on growing.

LB tuber resistance would be harder to monitor as it would only really be seen at or following harvest. I’m currently of the thinking though that if the tops have remained healthy then the chances of LB being present in the underground crop would be small? Although if any were infected, it would be fairly easy to separate the crop of any plants showing blighted tubers at point of harvest. I suppose some potatoes could be dug early and LB introduced?

My plans for 2015
To grow several Blight resistant varieties and use them to make crosses to feed into a genepool.

Sow TPS from any Blight resistant varieties I already have and trial them, purely survival of the fittest clone or cones go forward.

Monitor with Sarpo Mira and non resistant varieties, perhaps a blight rating table on how a variety performs against blight might be handy

Simples!!!

[jayb]

I'm making a start on my list for next year, so far
Sarpo Mira tps
Sarpo Mira x Red Cara tps
Tibet tps
Bolivian Yellow Hesh tps

I've a few more to add before choosing but I've not harvested some berries yet so I won't add them in until I get seed.

[jayb]

I'd like to link this thread at Tom's Forum http://tatermater.proboards.com/thre...&scrollTo=7701

[jayb]

Also possible tps for growing next year;
Sárpo Mira x Lumper
Sárpo Mira x PFA
Sárpo Mira x Ratte
Sárpo Mira x Russian Blue

[jayb]

Seed Tubers
Sarpo Mira
Carolus - thank you Galina
Kifli
Palest Pink Eye from Tollocan Fiesta

[jayb]

I potted up some Sarpo Mira x Palest Pink Eye F1 seedlings yesterday, it will be interesting to see if any have inherited the same Late Blight resistance as their parents and how the different genes might combine.

[Galina]

The Palest Pink Eye in the garden are thriving, the foliage is filling out nicely. Same time last week the plants were about half the size they are now. Have earthed them up and mulched with grass and with chopped comfrey. They are happy in the same row with Snookie and Hot Dog - my lovely Welsh potato bed . No flowers yet, but I was perhaps a week or two late with planting potatoes. Really looking forward to them. And their blight resistance (thank you - huge problem every year here too). .

[Silverleaf]

It always amazes me how quickly potatoes grow once they get going! No flowers on any of mine yet except one Swift plant which made buds weeks ago that promptly dropped off.

I put a Snookie tuber in the straw bales with a few others (mostly Desirée and Chatlotte) from last year's harvest that went green, and although the others are doing well there's no sign of Snookie. Oh well. I'll give it a bit longer and see if it makes an appearance. I've never known a healthy-looking tuber to fail to sprout, so perhaps it's just being very slow.

[jayb]

I hope it does come through, they are quite fun and tasty.

[Silverleaf]

Did my rounds early this morning and lo and behold, there are some little green leaves where I planted Snookie! Yay!

So it really was just a lot slower to take off than the others, but I'm sure it'll do fine now it's up through the straw.

[jayb]

Yayy, go Snookie!

[jayb]

The Palest Pink Eye in the garden are thriving, the foliage is filling out nicely. Same time last week the plants were about half the size they are now. Have earthed them up and mulched with grass and with chopped comfrey. They are happy in the same row with Snookie and Hot Dog - my lovely Welsh potato bed . No flowers yet, but I was perhaps a week or two late with planting potatoes. Really looking forward to them. And their blight resistance (thank you - huge problem every year here too). .

Glad they are doing well
Mine aren't anywhere near to flowering either.

I really hope Palest Pink Eye gives the same LB resistant results for you, I'm pretty sure different parts of the country might have slightly different strains of LB and who's to know what mutations might bring this year. Taste I found good. I've got mine growing along side Carolus and Sarpo Mira with Blue Belle as the control.

[jayb]

Seedlings have grown on quite quickly and are ready for planting out. In the trays, Palest Pink Eye TPS and Sarpo Mira x Palest Pink Eye TPS,

I'm hoping they are not too late to be able to set a crop but wanted to give a later planting to hit prime blight time! Hope to find some with good resistance. I'll also be planting out some Sarpo Mira TPS.

[Galina]

Palest Pink Eye looking good, but no signs of flowers yet (late June)

[jayb]

Looks happy, it is quite a late one. Mine have some buds but no open flowers, whereas Sarpo Mira and Carolus both have flowers although not many. Lots of flowers haven't formed properly this year and have dropped off rather than developed. I've tried hand pollinating some of the Carolus blooms but they are very tight on shedding pollen and no luck so far. Also I've made several crosses Carolus x Sarpo Mira, bit early to see if they have taken, I'm not very hopeful. I'll try a few Sarpo Mira x Carolus and see if I can capture the cross that way.

[Galina]

You are busy . All I have managed to do was jiggle my early potato flowers a bit to see whether I can help set more berries than happens naturally (like very few or none). Should I use a little brush? Little finger? I can't actually see the pollen, maybe I am looking at the wrong stage. How do you mechanically do your fabulous crosses. If you have told us, sorry I've forgotten. The blooms are so open, is it necessary to flower bag them? Presumably yes?

No flowers (yet) on Carolus here.

[jayb]

I do pretty much the same as for tomatoes and I use an electric tooth brush for collecting pollen and then dab a little on. No need to bag blooms unless you want to. I'm sure some do get cross pollinated but as potatoes grown from tps are so varied I've never worried about it - unless I'm making a cross but even then I just emasculate the flower I want to pollinate, I don't bag the pollen donor flowers, so some stray grains may make it. I'm sure I have some pictures somewhere.

[jayb]

Planted out into furrows

Palest Pink Eye tps



Sarpo Mira x PPE F1 tps




Sarpo Mira tps