Each difference between T. dimococcum and both parental species is significant with P=0.0002.
The occurrence of fully brittle plants in C1 and C2 must be explained as hybrid combination; the spikes disarticulate like dicoccum (wedge type).
The empty glumes resemble both parents; they are sharply keeled and have a big long, inwardly bent keel-tooth like dicoccum, and a straight, pointed, smaller 2nd tooth like monococcum. The palea is undivided as in dicoccum. The grains are firmly enclosed in the glumes, as in both parents.
The fertility of pollen is reduced in C2 and C3 varying from 50-90% against the parents with 96% and 97%. The fertility on the female side in C2 is still more reduced and more variable. Assuming that 1 grain per spikelet is normal for monococcum and 2 for dicoccum and dimococcum, the variability is from 86 to 100% in monococoum, 68 to 97% in dicoccum and 0 to 95% in dimococcum.
As a result the experimentally synthesized amphidiploids show none of the characters of hexaploid wheats, (especially of the naked wheats), which separate them from the tetraploids.
1) T. compactum is a naked wheat-T. dimococcum a spelted wheat.
2) The form of the empty glume separates T. dimococcum from the hexaploid spelted wheats as well as from the naked ones.
3) The disarticulation of T. dimococcum is of the dicoccum, not of the Spelta-type (wedge-, not barrel-type).
The compactum problem remains unsolved until the following facts are reconciled.
a) T. compactum is verified archaeologically until now only for neolithic Middle Europe, together with Einkorn, Emmer and barley.
b) T. compactum is a cultural relict in Middle and Northern Europe up to recent times.
c) T. compactum is found in every extensive area of T. aestivum in the Near and Middle East, either as an admixture or as a locally limited crop (thus it is found also in the area of Aegilops squarrosa).
d) The problem of T. compactum is in the end always connected to the Spelta-problem.