A friend and I spent a few hours visiting with the profession breeder yesterday. There is a lot of information which I am not at liberty to discuss/share. Please don't ask me to expand on things as this is what I can share. No photos were allowed (I asked once at something rather generic but he explained the legal reasons for the "no" answer). He worked for 40 years for USDA (and maybe UC system?) breeding and then retired and is continued working independently since 2001.
In this thread there were suggestions about asking him about pruning, fertilizing, cold hardy breeding, etc. and none of these are things he has worked with. He has worked with a wide variety of fruits but his current fig work is presently developing common figs for commercial market. Much of the results of breeding work these days is not patented and made public but instead sold under an agreement where a royalty is paid on all future production (not just for 20 years). So, it is unlikely any of us will ever see the results of this work other than fresh fruit in markets. There is a chance that some extras may be patented and sold through a large retail nursery and those we would see.
It was interesting as the perceived market demand is for fruits such with Kadota-like eating qualities, over 50 grams, no cracks, good stem to make picking easier, fairly short neck to avoid damage when packed. Some of the nice figs we all enjoy would be rejects for his purposes. His taste preferences are much different than mine (does not like Panache or Col de Dame). This was disappointing to me personally but I guess large growers know what they are able to sell in the marketplace.
According to the breeder half of the seedlings that are produced will be caprifigs and I believe he said that half of the remainder would be Smyrna-type. He uses his own caprifig for most of his breeding and it is his not available to anyone else. He indicated that caprigs are bred along the same time while breeding for a common fig to get the results that are desired. He did not mention anything about a caprifig needing to be persistent to result in a seedling that produces a common fig and I got the impression that this was not the case.
Important features which are transmitted by the caprifig (usually?) are tight eye, size, color of skin (and maybe pulp, I think). The tight eye in California is desired to help keep insects out.
He indicated that those wishing to try their hand at breeding may want to work with 271-1, a caprifig that he had previously used. It has some Bealle and 228 in it's lineage.
He frequently keeps some California BROWN TURKEY!!! in his breeding lines to develop productive varieties as it is both precocious and productive with fruit at most nodes.
He said he can often get a seedling to fruit in 8 months. Speeding up the fruiting is best done by trying to grow the tree with a central leader to 4'-5' in height at which point it will usually start to produce fruit. From there on up it will fruit. Side branches can be moved as they will remain juvenile unless they are allowed to grow 4'-5' as well. If he has a seedling started late in the year he may graft it in the following spring to get it to grow faster so he can evaluate it sooner. He had one tree with many grafts on it for this purpose while he also had many trees in pots.
He worked with Bill Storey of UC Riverside some and briefly spoke of how Storey was very discouraged towards the end when blocks were being ripped out and that he then suffered blindness in one eye when a large avocado fell from a tree at struck him and he then died a couple of years later. Sounds like his life came apart in a sad way.
I mentioned the lack of fruiting of my Sierra tree which he helped develop. He asked of my source and he pointed out that fig trees propagated by tissue culture as mine was often return to juvenility and that they must be allowed to grow up for at least 4'-5' to start fruiting again. If I understood him correctly, I should root a new tip cuttings if I want a tree with branches that fruit at a low height. That is something folks should keep in mind when considering tissue culture trees.
For people that wished to collect pollen for breeding or caprification experiments, he shared how he collects pollen. He cuts off the bottom of the fig and holds it over a vial and taps it. He will place a cotton ball to close the vial and refrigerate it for up to a month or so. He has not tried freezing it and didn't have any opinion on how that might work even when I suggested that it be dried before freezing which I had read was done in chestnuts. He uses an awl for placement of pollen in a fig but has some other tools also, some of which are not practical for anyone wanting to develop any fruit for consumption as it involves making a hole in the fruit, etc. An eye dropper may also be useful though he avoids it because of difficulty in cleaning (needs to avoid any other pollen when breeding). He would not let me take a photo of his tools either, lol.
Hope some of this is interesting and/or useful to some of you.