Long term cold hardy citrus breeding project

[mikkel]

What is the supposed hardiness of US1279, US 1281 and US 1282?

[kumin]

US 1279 has Changsha Mandarin as it's Citrus parent. US 1281 and US 1282 have Cleopatra Mandarin as their Citrus parent. Based on their parentage I believe the scales would tip in US 1279's favor in regards to cold hardiness. I haven't seen any trial results, however.
Additionally, Changsha is much sweeter than Cleopatra.

[tedburn]

I am not fully agree with your reasoning for rejection of of the progeny of direct hybrids between poncirus and edible citrus.
Of course, if you consider all the plants in F2, F3 and so on generations, they become more and more heterogeneous in respect of the presence of genes for hardiness, but due to the chromosome crossing-overs the two genomes will be progressively  present in the smaller and smaller intermingled fragments finally resulting in the separation of genes for bad  quality of poncirus fruits from the genes of hardiness in particular plants. This will be less possible in your pop3 and pop2 populations.

If you select for extreme hardiness ( comparable to that of poncirus ) in each subsequent generation of intercrossing inside pop5 population, and simultaneously keep selection for better and better  fruit quality, discarding the rest, you will produce hardy plants with higher and higher proportion of edible citrus genome.

Last year I obtained around  400 hybrid seedlings of 5star citrumelo crossed to Morton citrange and Batumi citrumelo. After selection for the absence of poncirus taste of leaves. I have around 50 plants of each cross growing in the ground.
Now I need a good cold winter  to see to what extent cold hardiness  and nasty poncirus aftertaste are linked.

Hello Ilya, this seems to be interesting crosses, how have they developped, concerning fruit and winterhardiness ?
Best regards Frank

[Ilya11]

If you select out of large hybrid populations, there are sufficient number of hardy plants. Absence of trifoliate taste can be also assured. But of course for sweetness, size of fruits etc., you need to wait for plant maturity. I have a dozen of plants that produce fruits, but have not yet attained my goal.

[tedburn]

thanks Ilya, always interesting to hear news of your huge
frosthardy citruscollection and your breeding work.