Can Tritipyrum, a New Salt Tolerant Potential Amphiploid, Be a Successful Cereal Like Triticale?

Soil affected by salt (NaCl) is a major problem worldwide and in areas with potential agriculture; lands in many countries are not enough to support crop production. The development of salt tolerant cultivars would be enhanced by better understanding of the genetic control of tolerance to salt stress. A new cereal, tritipyrum, a range of amphiploids between Triticum spp. and Thinopyrum spp. offers such a new chance. Those with the 6x construction (2n=6x=42, AABBE b E b ) derived from Triticum durum (2n=4x=28, AABB) and Thinopyrum bessarabicum (2n=2x=14, E b E b ) are of the potential to become a new high salt tolerant cereal crop. Tritipyrum is prone to problems similar to those exhibited by early triticales, e.g. chromosome instability and low fertility, which in that crop were eventually overcome by breeding. Other problems could be overcome through substitution of E b genome chromosomes by D genome ones, and the feasibility of this has been assessed in the progenies of (6x tritipyrum) x (6x wheat) hybrids with the aid of fluorescent in situ hybridization (FISH). The cytological, morphological and agronomic studies of existing tritipyrum lines, including the effect of vernalization, were carried out, too. A novel multiple-pistil/seed characteristic of one original tritipyrum line has also been investigated and its genetic basis established. The results have shown that, first creation of substituted lines is feasible, and thus it could be a route for the elimination of undesirable traits. Second, improvement should be possible via selection for chromosomally stable lines, with increased fertility and yield. Third, it may also be possible to exploit the perennial habit and multi-tillering traits in a dual-purpose forage/grain crop. Fourth, the multiple-pistil/seed trait may be controlled by two recessive genes. Fifth, there is a high probability of having established the seven possible monosomic additions of Th. bessarabicum to T.durum for the first time.