Hayes and Garber - Cucurbit Breeding

78 BREEDING CROP PLANTS
crosses between any form in the first group with any form in the
second group gave all cultivated forms of the spelt and emmer
groups in later generations. Tschermak (1913) obtained similar
results only from crossing solid and hollow stemmed varieties of
the respective groups and only obtained polonicum forms when
using polonicum as one of the parents.
HYBRID WMU>
FIG. 17. Wild wheat from Palestine and the New Hybrid. Here is shown a
spikelet of the true wild wheat and one of the hybrid forms. (After Love and
Craig, 1919.)
T. dicoccoides was reported as being found wild as early as
1885. Aaronsohn (1910) found many wild forms of T. dicoccoides
in Palestine. Love and Craig (19196) have produced
T. dicoccoides
synthetically by crossing durum and common varieties,
which indicates rather close genetic relationships between these
forms. There seems no very good reason to the writers for