Mystery seeds as sent to Patrick

[Rebsie]

Thank you Tom. After reading this and seeing the photo I immediately went and sowed twice as many seeds of #11 because this line looks fascinating. Appropriately enough, they have turned out to be the first to germinate.

I'm new to working with polyploids and still trying to understand how they work ... what usually happens when you cross a diploid with a tetraploid? Is there an advantage to diploid potatoes over tetraploids?

[Tom Wagner]

Rebsie,
I was thinking of you when I found this link from a journal in Oxford. This article and link below emphasizes my interest in diploids in breeding.

jxb.oxfordjournals.org/cgi/content/full/ern264v1

Quality traits such as flavour and texture are assuming a greater importance in crop breeding programmes. This study takes advantage of potato germplasm differentiated in tuber flavour and texture traits. A recently developed 44 000-element potato microarray was used to identify tuber gene expression profiles that correspond to differences in tuber flavour and texture as well as carotenoid content and dormancy characteristics. Gene expression was compared in two Solanum tuberosum group Phureja cultivars and two S. tuberosum group Tuberosum cultivars; 309 genes were significantly and consistently up-regulated in Phureja, whereas 555 genes were down-regulated. Approximately 46% of the genes in these lists can be identified from their annotation and amongst these are candidates that may underpin the Phureja/Tuberosum trait differences. For example, a clear difference in the cooked tuber volatile profile is the higher level of the sesquiterpene -copaene in Phureja compared with Tuberosum. A sesquiterpene synthase gene was identified as being more highly expressed in Phureja tubers and its corresponding full-length cDNA was demonstrated to encode -copaene synthase. Other potential ‘flavour genes’, identified from their differential expression profiles, include those encoding branched-chain amino acid aminotransferase and a ribonuclease suggesting a mechanism for 5'-ribonucleotide formation in potato tubers on cooking. Major differences in the expression levels of genes involved in cell wall biosynthesis (and potentially texture) were also identified, including genes encoding pectin acetylesterase, xyloglucan endotransglycosylase and pectin methylesterase. Other gene expression differences that may impact tuber carotenoid content and tuber life-cycle phenotypes are discussed.

I know, I know.....too complicated to digest all at once, but it illustrates my life long effort to understand the more esoteric to eventually apply to common-sense approaches to plant breeding.

The next quote indicates that we once had many Andean potatoes in Europe but those eventually became lost or introgressed into Chilean types and the diploids lost favor and numbers. What I am trying to do is bring back some of the diploid diversity.

Our results show that the Andean potato (lacking the DNA plastid deletion) first appeared in Europe around 1700 and persisted until 1892, long after the late blight epidemics, while the Chilean potato (possessing the deletion) first appeared in Europe in 1811, long before the late blight epidemics and persisted until the present day, when over 99% of extant modern potato cultivars possess Chilean cytoplasm (Hosaka 1993 , Hosaka 1995 ; Powell et al., 1993 ; Provan et al., 1999 ) (Fig. 4). This includes an extant cultivar Yam, released in 1836 before the late blight epidemics (Powell et al., 1993 ). Of the period from 1811 to 1850, 9 of the 16 specimens (56.3%) possessed Chilean cytoplasm (Fig. 4).

www.amjbot.org/content/vol95/issue2/images/medium/252fig4.gif

Chronological summary of the 241-bp deletion in the trnV-UAC/ndhC intergenic spacer region of the plastid DNA of 49 herbarium specimens of Solanum tuberosum collected in Europe from the early 1700s to 1910, distinguishing germplasm originating from the high Andes or from lowland Chile. The gray box highlights those collected before the late blight epidemics that were well established in the UK by 1850.
Particularly compelling are the chloroplast DNA data showing well over 99% of extant potatoes (Definition: Surviving / still in existence) today to have Chilean germplasm. …..99%) of extant modern potato cultivars have T-type DNA typical of most Chilean germplasm

The tetraploid cytotypes are the highest yielding; they are the sole cytotype of modern cultivars That is one reason I am trying to find some good diploids to introgressed by hybridization or by unreduced gametes some tetraploid vigor from stenotomum types.

The conditions for the establishment of a tetraploid in a diploid population were investigated by means of a deterministic model, on the assumption that the diploid cytotype produces some 2n gametes.
If the fertility and viability of both cytotypes were the same and the initial population was diploid, then a mixed population would occur if the production of 2n gametes was below 17.16%. The tetraploid excluded the diploid above this limit. By modifying the fertility and the viability of the polyploid this threshold varied, dropping to 10% when one of the two parameters was twice that of the diploid, and falling to as low as 6% if both fertility and viability were double that of the diploid.
The conditions for the establishment of a polyploid are therefore quite restrictive under the assumptions of this model. In nature, such processes would probably allow the spread of the polyploid only if the immigration of polyploids considerably enhanced the frequency of tetraploids, or if genetical or environmental changes, or chance processes in small populations caused a substantial increase in the frequency of 2n gametes produced by the diploid.

On an earlier post I mentioned I am saving my Big Nine clone from two year old tubers. Big Nine is an example of a clone derived from both an unreduced egg gamete and pollen gamete. The yield is four or more times the yield of its diploid sisters.

cytotype (plural cytotypes)
1. (genetics) An individual of a species that has a different chromosomal factor to another

Dihaploids of Solanum tuberosum may have a regular form of calyx with relatively short sepals similar to that found in the diploid, wild species,S. sparsipilum, or an irregular form with relatively long sepals similar to that found in the cultivated, diploid species,S. stenotomum. The regular form is due to a dominant gene which may be strongly linked to theS genes controlling self-incompatibility. The results support the hypothesis thatS. tuberosum is a segmental allotetraploid produced by the doubling of chromosome number of a hybrid betweenS. stenotomum and a species with a regular calyx.

The fact that our domesticated potatoes are derived from S. stenotomum is fascinating to me and I am trying to re-introduce some of its own history. So, Rebsie.....look for the long calyx on your seedlings...the ones that came up quickly from true seed. Of course, I know they will bloom for you and a photo would be nice to show the long calyx structures.

Tom ....too long on fascinating hints to what this work could be in the future...but a bookmark to add more research.

[Rebsie]

Thank you Tom, that's brilliant. I need to do some homework on my genetic terminology but it does me good and encourages me to learn. I'm all for reintroducing some of the historic diversity. The Khuchi Akita shape is very different from anything I've seen in Europe, and I love diversity!

I will be sure to take lots of photos as the plants develop and I'll look out for the long calyx.

[Tom Wagner]

www.flickr.com/photos/rebsiefairholm/4548865417/in/set-72157623402333058/

Thanks for showing the potato seedlings from John Tom Kaighin. The above pictures show the new seedlings. I found the site from my Google Alerts.

[Rebsie]

Here's a couple more, taken today.


#8 of the mystery seeds: Mandel x John Tom Kaighin F1


And here's #11, the Pirampo x Khuchi Akita F3. There are already some distinct colour differences in the seedlings.

[Tom Wagner]

Go Back to a lively discussion over at ......... Tomatoville® Gardening Forums Index > What Else Do You Grow? > Potatoes > Curzio Garlic and More where myself and Sari talk about Mandel (Peanut) and other names for it. I talked about the Mandel x John Tom Kaighin cross there and Rebsie has it. Of course, so do I.

oregonstate.edu/potatoes/variety-L_files/Peanut%20fingerling.pdf
has a nice description of Mandel. Naturally, I think the seedlings of the cross Rebsie has will have a wide variety of outstanding texture and flavor components. I hope Rebsie will have a least one seedling that could be expanding in production so if I visit the UK again, I might just get a chance to taste one of her selections. Thanks, Rebsie for showing the emerging seedlings. I see the label...and sigh...

[Rebsie]

Interesting to read about Mandel. So it's a pretty old variety by the look of it, with good flavour but poor blight resistance ... so presumably the cross with John Tom Kaighin might result in some offspring with flavour and blight resistance. Although it's a European potato, Mandel is not easily available in the UK. I've never seen it sold here. So it's really useful to be able to read up on some background info for it.

Of course Tom, if you find yourself back in the UK any time it would be an honour to share the results of the potato project with you.

[Rebsie]

A little update. The seedlings have been planted out in the garden this week.


This one is a Pirampo x Khuchi Akita F3.



Pam Wagner F2. I have four of these seedlings, and one (on the left) is showing a lot of colour in the stem while the others are more green.



Skagit Valley Gold x Thumbed Nose F1. These plants have a distinctly yellowy-green foliage, although it's not that clear in the photo.


Another Pirampo x Khuchi Akita F3. This one has some deep colour in the stem and leaf veins.[/img]

[Rebsie]

Another Pirampo x Khuchi Akita F3. This one has darker colour in the stem and leaf veins.

[Tom Wagner]

Thanks for those photos, Rebsie,,,,,,I owe you!

The one that has the SVG and Thumbed Nose pedigree with yellowish leaves indicates that it will have near orange/yellow flesh.

The F-2 Pam Wagner clone with the color in the stem will be red skinned and the others may be white skinned. The R genes for Late Blight resistance should be bouncing around big time since the parent and both grandparents had great field resistance here.

That last photo will produce great flowers...let me tell you now....

[Rebsie]

Another little photo update.

This is the same Pirampo x Khuchi Akita plant shown in the previous photo (I think).




Here's a Mandel x John Tom Kaighin F1, which is doing well.




This one is still unidentified! It was #29 in the series of seeds Tom brought to Europe, but I have no pedigree information for it. It has pale green leaves and some pinkish axillary pigment. Any ideas?

[Rebsie]

Some interesting calyx shapes among the diploids. I should probably wait until they flower before posting pictures but I'm so excited to see buds on them I get a bit ahead of myself.

This is Skagit Valley Gold x Thumbed Nose F1, with a very elongated calyx. I have two plants of this hybrid, and they are very different from each other (the other is taller with darker leaves, and is not yet showing any buds).




Two plants of Pirampo x Khuchi Akita F3. These plants both have a long calyx but the shape is very different. One is spiky and pointy while the other has very rounded ends.

[Tom Wagner]

Hope one of those will have the blue flowers of Thumbed Nose rather than the pink mauve of SVG. With all the diverse pedigree floating around it will be a virtual hutsput mit klapstuk.

[PatrickW]

Jul 1, 2010 11:31:23 GMT -8 Tom Wagner said:

With all the diverse pedigree floating around it will be a virtual hutsput mit klapstuk.

Beef stew!

[Tom Wagner]

Thanks, Patrick for picking up on the hutsput mit klapstuk. A good beef stew is hard to find, unless you make it yourself.

When I was in the Netherlands 14 years ago I was able, with several requests, to get some hodge podge with cheap cuts of meat. It had the carrots, potatoes, and meat plus a few other things for flavor. It was the best food I had in Europe that time.

There is a similar sounding dish in German or Luxembourg. Typicallly in our family we used the left over roast beef...cut it up in cubes...added the broth and meat to a huigh batch of carrots and potatoes with a few onions.