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We may say from all these informations, including the present results, that the nuclear genomes of T. urartu , and emmer wheat are incompatible, whereas that between the genomes of T. boeoticum and emmer wheat are compatible. We then fall in a paradox between two generally accepted hypotheses, i. e., T. urartu provided the A genome (ref. Introduction), and Ae. speltoides donated the B genome to emmer wheat (Sarkar and Stebbins 1956; Tsunewaki 1988; Dvorak and Zhang 1990). Based on these two hypotheses, we may assume that the A genomes of T. urartu and emmer wheat are compatible, and, similarly, that the A genome of T. urartu , and the B of emmer wheat are compatible, because the F1 hybrid between T. urartu and Ae. speltoides had been produced in the past to give rise to the present-day emmer wheat. Then, we can deduce logically that the nuclear genomes of T. urartu and emmer wheat should be compatible, but actually they were not. Of course, we may postulate different events that might have occurred during evolution of all those species. An approach to solve this enigma is to cross the F1 hybrid between T. urartu and T. boeoticum to emmer wheat, and investigate the progeny of this cross.

References

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