I have a lot of questions about the genetics of 'firmness' and texture and slow ripening myself, after this past season growing F2's of a cross with Zolotoe Serdtse.
The F1 crosses were as firm and slow ripening as the mother ZS.
The F2's varied a little, but every one of them had some degree of the slow ripening and firm texture.
Frogsleap, that's a very interesting paper you posted. I half understand what is being said about skewed distributions, but I am still confused about nor, rin and alc all appearing to be recessive? While the paper also says a large number of dominant genes are involved.
And for fruit firmness they identified four QTL's.. I don't understand how that corresponds to the three 'mutants' alc nor rin.