| In 1968 progenies of the collected ears were grown in Hannover but only
such progenies are listed in Table 1 from which
the somatic chromosome number of the mother ear have been checked up in
order to make sure that the morphological classification into the two groups
carthlicum and carthlicoides have been correct. The analysis
revealed the existence of 3 different populations: 1. populations in which probably exclusively tetraploid carthlicum types are included such as the collection numbers 19, 24, 28, 29, 32, 34 and 35. They are concentrated between Cildir and Ardahan. 2. populations in which only hexaploid carthlicoides types could be found ; collection number 10 and 25. 3. populations with carthlcium- and carthlicoides types ; collection number 18 and 36. Of particular interest are the two dicoccum populations near Cildir, locality 30 and 31. They are characterized by some admixtures of an hexaploid spelt type, probably of T. aestivum ssp. macha. Unfortunately they were not yet ripe and I did not succeed in getting seeds after the harvest. In Hannover field observations were carried out in 1968 as to the resistance resp. susceptibility to powdery mildew, Erysiphe graminis tritici EL. MARCHAL, and having been scored with 1-5. As far as it is possible to draw any conclusion from one year-observation without any replication the more resistant types prevail in the tetraploid group. Some exceptions do occur, particulary in collection 32 and 33. The reaction of some progenies to Puccinia striiformis WEST. was tested by Mrs. Dr. E. FUCHS ; the seedling stage in greenhouse to race 20 A which is very common in the Near East, and in the field to race 8. Although the results are to small to draw any conclusion, but there might be some indication that resistant types are more frequent in the carthlicum group than in the carthlicoides group. On the basis of the analysis of these findings I would like to propose the following hypothesis as to the origin of T. carthlicum: the hexaploid T. aestivum ssp. carthlicoides should be considered as the elder (original) species. Spontaneous crosses between both species, T. dicoccum and T. aestivum ssp. carthlicoides are assumed. As both species are still spread over the same area to-day, such an hybridization is rather likely. In the following generation of the pentaploid hybrid, 2n=35, with the genome formula AABBD the chromosomes of the D-genome were eliminated. By recombination and crossing over between the chromosomes of the A-genome as well as between these of the B-genome T. carthlicum as a new recombinant among many other genotypes was evolved. In this species genes responsible to the particular morphology of the hexaploid parent are combined with the genes for resistance to rust and mildew by which the tetraploid T. dicoccum is distinguished. |
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