Suggested crosses for zone 8 - Who is doing what in Europe?

[solko]

Hi all,

As an amateur breeder I am finally trying to start a small program to create new citrus hybrids with hopefully interesting flavors and uses for my zone 8 climate. From working with other species I know how much time, space and effort goes into even a small program and I was wondering who is already trying out certain crosses in Europe, since I don't necessarily want to do the same ten year experiment.

I know of course that everyone would get different results from the same crosses, but I was wondering if it would not be more interesting to try something new that someone else was not doing yet.

I have been collecting some varieties since five years and do have some of the hardy varieties starting to flower this year. I am also looking to buy some new varieties that may give 100% zygotic seedlings. There is a table of the percentage of heterozygosity of seeds of different cultivars over at the tropicalfruitforum and it states that Ichangquat 6-7-2 gives 100% heterozygous seedlings. Is someone already breeding with this variety and has that been your experience?

Another question is do you  know where I could buy this Ichangquat 6-7-2 in Europe? I was planning to use this as the cold-hardy parent of my crosses to make and ended up on this forum when looking where to get it.

Ilya knows a lot more about this variety than anyhting I have found online. Ilya, could you tell me if the Ichangquat that I can find at Lenzi or at the Czech nurseries is indeed this Ichangquat 6-7-2 and that it produces heterozygous crosses?

And if any of you have any other suggestions of good coldhardy parents, please let me know! I was going to stay away from making my own poncirus crosses, because I want to create new fruits for zone 8, so I may use some poncirus hybrids, but thought it may be more useful to start with other parents.

Please let me know what you think, and if someone is already doing this in Europe, what other crosses may be useful to consider.

Thanks!

Solko

[ilya11]

Feb 18, 2024 9:46:04 GMT -5 solko said:

 There is a table of the percentage of heterozygosity of seeds of different cultivars over at the tropicalfruitforum and it states that Ichangquat 6-7-2 gives 100% heterozygous seedlings. Is someone already breeding with this variety and has that been your experience?

Another question is do you  know where I could buy this Ichangquat 6-7-2 in Europe? I was planning to use this as the cold-hardy parent of my crosses to make and ended up on this forum when looking where to get it.

Ilya knows a lot more about this variety than anyhting I have found online. Ilya, could you tell me if the Ichangquat that I can find at Lenzi or at the Czech nurseries is indeed this Ichangquat 6-7-2 and that it produces heterozygous crosses?

I  do not know for sure, but it seems that Adavo got the twigs of 6-7-2 from  me trough Z.Cernoch and they are still using a photo of my plant. 

The problem of using it in hybridization is  that  there is a rather low level  of pollinated flowers giving mature fruits, low number of flowers in the first, spring wave and  a low  seed content per fruit. 

Under my field open pollination the fruits are giving both green  and white embryo seeds at the ratio of ~1:3.

[solko]

Hi Ilya, Thank you for that clarification. As a breeder with limited space I don't know if that is a real problem for me, as long as the final fruits have a chance of being of interest. I would be happy to only end up with a few seeds per year to grow, but maybe I will indeed put two or three potted citrus next to the beehives and let nature do the rest. The advantage of being so far north is that even in my community garden plot there is no other citrus around to cross pollinate anything that I will put outside, so I could control the crosses in that way. I have read about a different color of the seeds in citrus (and of course in corn) as a sign of cross pollination, but I didn't know that you could distinguish the two that easily with ichangquat, that will also help a lot. Just to make sure that I get it right: are the green or the white embryo's the heterozygous ones? And would that work for Thomasville as well?

Would you know if as another possible parent Ichangensis IVIA has any obvious drawbacks? I would like to make crosses with the Ichangensis as a source for hardiness, but I have read very mixed reports about the hardiness of the IVIA, some say it is their hardiest plant, others say it is the least hardy of the Ichangensis, but it does have the best flavor and juiciness. Is anyone already making crosses with it and would you think it is a good parent to start with?

[ilya11]

Hello Solko,

From my observations at least in my environment 6-7-2 is giving entirely zygotic seedlings. Green embryos are probably  a heritage of kumquat, white ones are from ichangensis.

I germinated hundreds of Thomasville seeds  and never seen any hybrids, but had several hybrid seedlings when its pollen was used.

I have IVIA in the open without any protection for 6 years and it never has been damaged. Very early partogenetic and zygotic variety.

[solko]

That is great news about the IVIA, Ilya, thank you.
That opens up the perspective of making crosses with more tender and good tasting citrus and doing a mass-selection in my relatively mild winters here. I am a bit further north of Paris, but also a bit closer to the see, so the last ten winter we get around two times per year a week or ten days of frost, with one period of 4 to 5 days of continuous temps below 0. But the minimum is usually only -8 or -9.
I am a bit late in the year to shop around for citrus, it looks like everything is sold out already so I will try to get an IVIA when the next round of young plants becomes available. For this year I will already have enough flowering plants and I am looking forward to start trying out my first crosses and different pollination techniques.