Does anyone know if citrangequats can be used as the pollen parent in hybridising?

Have read somewhere that as a group they are pollen sterile but cannot see any particular reason why this should be or if it is so why it would be total. Surely where poncirus/orange genes or fortunella/orange genes dominate some viability would be present. Only where poncirus/fortunella genes combine may viability be affected.

I used Thomasville pollen on my Swingle5*and found that one should surcharge the pistil with dried and grinded anthers to produce any seeds.
I finally have one putative hybrid that for the moment resembles Thomasvile parent.

Thanks Ilya

It certainly looks like low viability.

Citrumelo/thomasville was one of the hybrids was wanting to make.

Ilya

Have you ever tried thomasville pollen on the ichangquat, to see if it might be a function of fortunella ancestry?

Even some of the kumquats won't hybridise with each other but genetically according to mDNA are all japonica forms. We cannot have seen last on citrus genetics yet.

Dr. Brown wrote that Morton has good pollen. It was in some paper uploaded here in the forum.
Sanford Curafora creates some seeds on Swingle 5 Star. I could not prove what they are like because the fruit fell off this winter. It was not ripe because the flower had come too late. But the presence of seeds indicates that the pollen was good.
It makes a great difference by the way how fresh pollen is. I did not manage to produce hybrids with Moro pollen stored in a warm room. And Poncirus pollen did not work on Meyer Lemon after some months stored in the refrigerator. But it worked on Sanford Curafora when it was only some weeks old.
These are my limited experiences.

But that most citranges are sterile seems to be wrong. Swingle writes the opposite that citranges usually have some viable pollen. And his faculty did in fact make hundreds of crosses with citranges as mother and as father plants. One surviving example is the Willits citrange, the mother of Thomasville citrangequat.

Sterile pollen can be due to incomplete chromosome assortment in the pollen gametes. Humans are diploid, and their gametes ( sperm and ova) are haploid, or half the genes from the parent. A new human is again diploid.
Citrus plants are diploid or triploid or tetraploid. Diploids can simply create haploid gametes, but triploids etc can make unworkable combinations.
Seedlessness in triploid Citrus can also be due to this.
Occasionally it is possible to get functional gametes from non diploids, if a workable combination of chromosomes is transferred.

Seedlessness could be due to other factors, seedless Kishu is diploid but aborts zygots after pollination.

Currently Cybridization is becoming frequently used to develop seedless citrus. A method called cybridization transfers a sterility gene into seedy citrus varieties, rendering them seedless much more efficiently than the shotgun approach used in irradiation. - Mllet