Aruanda
Well-Known Member
I'll be reading through this more extensively. What I am curious about at this point is the preservation of heirloom cultivars and landraces. I would like to eventually get involved in breeding for new and novel traits however.
Some things I am trying to understand are, if you acquired seeds that come from an IBL/True breeding cultivar (NL, Skunk#1, etc), would preserving that cultivar be a question of open pollination, line breeding, 'recurrent selection,' 'reciprocal recurrent selection,' and 'convergent improvement?'
It would seem that open pollination may be a good option if you started with limited seed stock, to preserve genetic diversity perhaps. Then carrying out line breeding with these other techniques to distinguish characteristic 'lines' within the same cultivar and create multiple IBL within a cultivar and then once these are stabilized, cross them between themselves (if I understood RS/RRS/CI correctly). I suppose this could be carried on indefinitely and would perhaps protect against loss of vigor? I've also read that loss of vigor that comes about from an IBL over time may not be such an important factor when considering some of these cultivars have been inbred for a long time.
Another aspect of this is if you were to acquire F1 seeds of a new hybrid variety and wished to preserve that cultivar. I would like to quote one part of the OP's text:
"Watts defines an F1 as the heterozygous offspring between two homozygous but unrelated seedlines. This makes sense and gives the F1 generation a unique combination of traits; uniform phenotype but not true breeding. This is important in the plant breeding world. This means that when a customer buys F1 seeds that they should expect uniform results. It also means that the breeder's work is protected from being duplicated by any other means than using the original P1 (true breeding parents). [There are
exceptions to this by using techniques such as repeated backcrosses (cubing the clone)."
So in this instance, I may start with a limited number of F1 seeds and get a pretty uniform phenotype but no access to the P1 stock so preserving the cultivar becomes more challenging. I am assuming then I'd select one or a few breeding pairs within the population that are exemplary of the cultivar and use those as mothers/fathers and produce a F2 with which to proceed with backcrossing/cubing to improve the gene frequencies. I've seen this information regarding protecting breeders work in a few texts, and it may be that the OP quoted this from Clarke's work too. I find this information to be curious.
So in this example, what this tells me is, if I buy F1 Hybrid seeds of a new cultivar (at about $120 for 10 seeds, on average) of some elite genetics, where is the value of these seeds? It would seem that the most practical for most people is to buy seeds and keep clones of exemplary specimens, but keeping clones doesn't seem the most secure way to preserve genetic material/cultivars? So for me personally, the ideal would be buy a pack of expensive seeds or a few packs, then inbreed them, selecting the best specimens and continue the line. But the breeder made the effort to ensure that if I do this, I should end up with differing genetics and no longer breeding the same cultivar unless I take additional steps which may or may not preserve the genetic lineage. To me, such work makes these elite genetics less valuable as it may be difficult or near impossible to preserve a cultivar without just keeping clones or buying new stock year after year.
I'm obviously trying to wrap my head around this and thinking out loud on my own rationalizations for how this all works. Maybe I am not seeing the whole picture on certain aspects yet but any input is much appreciated.
Some things I am trying to understand are, if you acquired seeds that come from an IBL/True breeding cultivar (NL, Skunk#1, etc), would preserving that cultivar be a question of open pollination, line breeding, 'recurrent selection,' 'reciprocal recurrent selection,' and 'convergent improvement?'
It would seem that open pollination may be a good option if you started with limited seed stock, to preserve genetic diversity perhaps. Then carrying out line breeding with these other techniques to distinguish characteristic 'lines' within the same cultivar and create multiple IBL within a cultivar and then once these are stabilized, cross them between themselves (if I understood RS/RRS/CI correctly). I suppose this could be carried on indefinitely and would perhaps protect against loss of vigor? I've also read that loss of vigor that comes about from an IBL over time may not be such an important factor when considering some of these cultivars have been inbred for a long time.
Another aspect of this is if you were to acquire F1 seeds of a new hybrid variety and wished to preserve that cultivar. I would like to quote one part of the OP's text:
"Watts defines an F1 as the heterozygous offspring between two homozygous but unrelated seedlines. This makes sense and gives the F1 generation a unique combination of traits; uniform phenotype but not true breeding. This is important in the plant breeding world. This means that when a customer buys F1 seeds that they should expect uniform results. It also means that the breeder's work is protected from being duplicated by any other means than using the original P1 (true breeding parents). [There are
exceptions to this by using techniques such as repeated backcrosses (cubing the clone)."
So in this instance, I may start with a limited number of F1 seeds and get a pretty uniform phenotype but no access to the P1 stock so preserving the cultivar becomes more challenging. I am assuming then I'd select one or a few breeding pairs within the population that are exemplary of the cultivar and use those as mothers/fathers and produce a F2 with which to proceed with backcrossing/cubing to improve the gene frequencies. I've seen this information regarding protecting breeders work in a few texts, and it may be that the OP quoted this from Clarke's work too. I find this information to be curious.
So in this example, what this tells me is, if I buy F1 Hybrid seeds of a new cultivar (at about $120 for 10 seeds, on average) of some elite genetics, where is the value of these seeds? It would seem that the most practical for most people is to buy seeds and keep clones of exemplary specimens, but keeping clones doesn't seem the most secure way to preserve genetic material/cultivars? So for me personally, the ideal would be buy a pack of expensive seeds or a few packs, then inbreed them, selecting the best specimens and continue the line. But the breeder made the effort to ensure that if I do this, I should end up with differing genetics and no longer breeding the same cultivar unless I take additional steps which may or may not preserve the genetic lineage. To me, such work makes these elite genetics less valuable as it may be difficult or near impossible to preserve a cultivar without just keeping clones or buying new stock year after year.
I'm obviously trying to wrap my head around this and thinking out loud on my own rationalizations for how this all works. Maybe I am not seeing the whole picture on certain aspects yet but any input is much appreciated.
