Trying to figure out how to organize my goals in some logical way… I think I may post each one separately to allow explanation.
#1 Develop fertile broad genetic balanced wide cross strains – OT, LO, OA, LT, AT, etc.
So this goes back to some coaching I got from Bob Griesbach. I had the amazing opportunity to pick his brain and ask him all the questions I could think of. The question I want to focus on here is “based on your experience in breeding OT’s, what would you have done different or what would you do different today?” His answers to this were very helpful. The first recommendation he made was that for wide crosses – do this with plants that have a broader genetic make-up. For instance – ‘Black Beauty’ (BB) is a wide cross hybrid that has only genes from L. speciosum & L. henryi. His suggestion was to cross something with greater genetic diversity like and Oriental hybrid with an Aurelian hybrid as a starting point to get greater potential for genetic variation in future generations. Most of his OT’s were based on the cross of ‘Tetra Black Beauty’ (TBB) x ‘Tetra White Henryi’ (TWH) or the reciprocal cross. These hybrids have limited genetic variability – the got a double dose of L. henryi, and genes from L. speciosum & L. leucanthum. It has been amazing to see the diversity that came from just these 3 species, but his recommendation was to go broader to get more potential for variation in color, flower shape, & orientation. So one of the crosses I am going to try to make this summer is “Journey’s End’ (JE) x ‘White Henryi’ (WH) – the intent is to get some influence from L. auratum in the mix. I found a source selling JE and have them coming for spring delivery and hoping they are the real thing. I have ordered this several times in the past and have gotten the correct plant once and imposters a few times so hoping I get the correct on this time. I have other F1 OT crosses planned – this is just an example.
His next recommendation was not as intuitive to me initially. Bob recommended to try to keep the genetic content balanced. For instance, when working with OT’s, you want to keep the contribution of Oriental & Aurelian genes equal. BB is an F1 OT with equal input from Oriental (L. speciosum) & Aurelian (L. henryi). When he crossed this with WH he did not keep things balanced as WH is 100% Aurelian and the results were OTTT. He would instead would recommend crossing BB with another F1 OT like ‘Starburst Sensation’ (SS). To make this cross it would likely need to be done at the tetraploid level – BB is mostly sterile in the diploid form. SS though has been crossed with diploid Aurelian (to make Silk Road/Northern Carillon) and diploid Oriental (to make Anastasia) and these are triploids suggesting that SS may produce some unreduced gametes as a pod parent and could produce some seed when crossed with TBB. The reason for the recommendation to keep things “balanced” is to allow for normal chromosome pairing, potentially improved fertility, and better variation in successive generations. When the chromosomes from each wide cross group are not kept balanced, when the plant goes through meiosis, it is not able to find like chromosomes to pair with resulting in failure of meiosis and no fertile eggs or pollen. So what this looks like from a breeding strategy would be to make a number of F1 OT diploid seedlings from different broad genetic parent plants, convert them to tetraploid (or use unreduced gametes) and cross these F1 crosses to make F2 tetraploid balanced seedlings. These F2 seedlings would hopefully have some fertility to carryon and intercross with each other and from different lines. For instance – if I am able to achieve SS x BB, I would want to cross F2 siblings to create a line where I would look to breed F3, F4, & F5 and also with a completely different pair of similar make-up. A couple of other F1 OT’s that I will try to use are Smoky Mountain, Nymph, & Gluhwein – if I could get a similar F2 cross from Smoky Mountain x Gluhwein at the tetraploid level, then I would want to cross tetra (SS x BB) x tetra (Smoky Mountain x Gluhwein) and then these siblings would be intercrossed.
The whole point of this is to do something similar to what Bob did but with a broader genetic background to allow more variation and keeping things balanced with the intent to allow restored fertility. This same idea can be applied to other wide cross breeding groups. For instance, tetraploid AT’s would be a very logical step. There are a number of tetraploid Asiatic & Aurelian cultivars. Instead of starting at diploid, the wide crosses could be attempted with these tetraploid cultivars with the hope of having some fertility in the F1 generation.
This is a very different strategy that the Dutch breeders would suggest. They are breeding for triploids and generally are breeding back to one of the parents like an O x OT or an A x OA. In the end I don’t want to have to continue to use Embryo Rescue and Cut-Style pollination – this is just a stepping stone to get to generations of hopefully highly variable fertile seedlings. Triploids are not my goal as they are difficult to carry on in breeding – some can have fertility but recent papers suggest that most of the seedlings are aneuploids which can lead to more issues with fertility.
So the last piece of advice from Bob was to go deep. We already talked about starting wide (broad base of genetics) and then keeping things balanced to try to get fertility. Now we want to line breed to dig out the variations and recombinations in the genetics. That means going to F3, F4, and maybe F5 generation to see what you find. At any point of something unique appears, you would try to select a few similar seedlings and cross them to try to accentuate the unique trait. Bob did this for example with his "Lavender OT's" that came out of his TBB x TWH crosses. Once you have fertility - chase the trait of your liking or combination of traits...
More to come but probably all I have time for today.
