Sören's MarNar F2 Problem - RL AND PL Plants (pics)

[rnewste]

I've grown out Soren's F1 Marianna's Peace cross with Neves Azorean Red early this Summer. It was an excellent tasting variety:



I've been able to ferment seed from the F1 plants, to now start six F2 seedlings. What I am confused about is the fact that 5 of these seedlings are Regular Leaf (on the left), and 1 plant is looking more like a typical Potato Leaf plant (on the right):



Here is a closeup of the plant on the left:



This looks exactly like the leaves on all of my F1 plants.

Here is a closeup of the PL looking plant:



So, what is the "true" F2 plant that I should save seed from this Fall? I want to have F3 seed available for next Spring seedlings and I am not sure if the RL (or PL) plants are ones I should save seed from.

Raybo

[amideutch]

Ray, were dealing with a cross here. NAR is Regular leaf and MAR is PL. There is no True F2. So when it comes harvest time you make the choice based on fruit size, color, production and taste. Went through the same senario when PV did the NAR x Brandywine cross. PV settled on a PL pink/purple fruit that is now out to F6/F7. You be in the drivers seat. Ami

[rnewste]

Thanks Ami,

Yep, I was out chasing "skirts" (again) during Biology Class when the sessions on Plant Genetics were taught....

Let's see how the RL and PL plants develop over the next 3 months, and then draw conclusions on which F3 seeds I should save for the 2012 planting season.

Is there any significance to the fact that only one out of 6 F2 plants was a PL version?

Raybo

[amideutch]

I believe RL is the dominate trait. And it depends on which variety Soren used as the donor and which was the recipient. I too was looking at skirts in Biology class. Ami

[maf]

The theoretical ratio would be 75% RL and 25% PL, due to RL being a dominant gene and PL recessive; 5:1 is right in the zone of expected outcomes.

If you grow out the next generation after this you will find that the PL plants are fixed for PL, but some of the RL plants will segregate for leaf shape.

Here is a link that explains it better than I ever could, no biology classes required: http://kdcomm.net/~tomato/gene/genes.html

[travis]

Ray, you'll also notice that the plant leaf you show as "regular leaf" also does not replicate the leaf shape of Neves Azorean Red, rather it looks "intermediate" between RL and PL shapes.

If you were to grow enough F2 plants, you might find more variations of leaf forms running from the more narrow NAR regular leaf shapes, through the intermediate broadleaf RL or "lettuce leaf" shapes, to the 25% of the vines with true, smooth edged PL shapes, with even some variations in the PL shapes themselves.

For example, when I grew out Burpee's Brandy Boy, I got a variety of PL shapes. When I grew out a home cross very similar to Soren's F1, I got just what you're getting, and with even more variations (as I described above) the more F2 plants I grew.

By the way, your vines look fantastic, and you should have lots of fun with this cross.

[DanishGardener]

Ray, like others said, 25% PL in the F2 was expected

But keep selecting for the most important thing: Taste!
I would like to see both a new PL and a new RL variety from this cross, but that is secondary.
It will be interesting to see what you will find (taste-wise) in the F2.

[rnewste]

Soren,

An update on October 24.

Here are a pair of MarNar F1 plants which were put in September 3 as 15 inch seedlings:



Next, here are the pair of MarNar F2 planted out on August 30:



The taller plant on the right is the PL like version, while the one on the left is more of the traditional Neves Azorean Red leaf type. Interestingly, the RL plant set fruit 2 weeks earlier than the PL plant. So if one is interested in DTM, then the RL seeds would be better to use.



Fruit on the F2 plants are developing nicely, and I should have plenty of seed for F3 plants for next Season.

Raybo

[dustdevil]

With two plants in a 'tainer and all the 'tainers so close together, it would be hard to completely avoid cross-pollination.

[rnewste]

dust,

I had the two MarNar F1 plants which I saved seed from isolated in one EarthTainer in a remote location (see the first photo in my post of 4 weeks ago).

Now, I am growing out 6 MarNar F2 plants in 3 EarthTainers, all of which are adjacent to each other. F2 seed saving will be from the plant most isolated from other varieties in the Fall garden, which are about 25 feet away.

My belief is with this isolation, the MarNar F3 plants next Season should be true.

Raybo

[dustdevil]

Raybo,

I should have figured you'd have thought about that. Good to see a guy in his 90's is still on the ball

Dust