In message , Charlie
Pridham writes
In article ,
says...
In article ,
"Adam" writes:
|
| Are there any rules of thumb for which types of vegetables breed true? Or
| are there any lists out there somewhere of the best plants for harvesting
| seeds?
The closer to the wild form, the more likely. F1 hybrids almost never
will, most herbs almost always will.
Regards,
Nick Maclaren.
But if all you want is a carrot does it matter if the F1 variety does not
come true? you will still get carrots, you may even get as good a crop.
F1 in commercial seed production has a slightly different meaning than
in genetics.
In genetics the F1 (1st filial) generation is the plants raised from the
original cross, and is generally intermediate between the parents, but
many traits may favour one parent or another, and a few traits may be
outside the range of the parents. Seed collected from the F1 generation
gives rise to the F2 (2nd filial) generation, which can (if diploid)
show anything from one parent to the other. (Polyploid F2 generations
tend to be more similar to the F1 generation.)
The definition of F1 commercial seed has an additional criterion - that
the cross is between two inbred homozygous strains. This has a number of
implications. Firstly the F1 generation will be more uniform than seed
from an open pollinated strain. Secondly there will be a proportionally
greater increase in heterosis (hybrid vigour) compared to the parent
strains. This means that a loss of vigour and of desirable
characteristics is likely when you sow seed collected from F1 hybrid
plants, which is not the case when sowing seed from an open pollinated
strain. Without rogueing an open pollinated strain is likely to revert
towards wild-type over time, but this is a relatively slow process
resulting from the greater fitness of plants with more wild-type
characters. Cross pollination will accelerate this, as different strains
will be homozygous for non-wild-type alleles at different loci, and
cross pollination introduces wild-type alleles into a population that
lacks them, short-circuiting the need for a back mutation.
Bottom line - you're less likely to get a good result with seed
collection from F1 hybrid plants.
--
Stewart Robert Hinsley