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Author Topic: Thread for Citrus Breeders  (Read 159 times)

SoCal2warm

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Thread for Citrus Breeders
« on: June 27, 2017, 04:31:21 PM »
Is anyone here attempting to breed new varieties of citrus?
Share your breeding attempts or accomplishments here. Maybe we can exchange seeds.

SoCal2warm

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Re: Thread for Citrus Breeders
« Reply #1 on: July 18, 2017, 02:27:46 PM »
This may be interesting for some of you. As many of you know, many types of common citrus cultivars are considered to be polyembryonic (that produce seeds which are genetic clones of the parent). This can cause problems for breeding because most of the seeds in a polyembryonic cultivar will just be clones of the parent, rather than inheriting any traits from the parent the tree was pollinated with. However, not absolutely all of the seeds in a polyembryonic citrus variety will be clones, a few will be zygotic (the result of sexual recombination).

seed parent ... Seedlings/seed ... % nucellar
__________________________________________
Lemon: Eureka, Lisbon, etc ...  1.05-1.06 ...   32-33
Rough Lemon ...  1.24-1.96 ... 54-98
Mexican Lime ... 1.29 ... 78
Mandarin: Dancy, Kara ... 1.37-1.71 ... 100
Mandarin: Satsuma ... 1.44 ... 90
Mandarin: Kishu ... 1.00 ... 0
Mandarin: King, Ponkan ... 1.01-1.42 ... 21-98
Grapefruit: Marsh ... 1.08 ... 96
pummelo: 11 cultivars ... 1.00 ... 0
Sweet orange: 4 cultivars ... 1.09-2.00 .... 39-97
Sour orange ... 1.21 ... 85
Tangelo: Orlando, Minneola ... 1.31-1.49 ... 83-97
Trifoliate orange ... 1.03-1.26 ... 13-73
__________________________________________
data in this table comes from Frost and Soost (1968)

As can be seen in this table, pummelos produce all zygotic seedling, while almost all of the seeds in a Marsh grapefruit will be nucellar (clones of the parent)

So it is possible to use polyembryonic parents as the seed parent in breeding, but you just have to grow a lot of seedlings and see what they all become. This might not be practically possible in Dancy and Kara, however, because there were none of their seeds that were not nucellar in this experiment.



 

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