Cytogenetic Study on the Formation of Amphiploids in the F_1 Hybrids of Triticurn carthlicum Nevskivar and Aegilops tauschii Cosson Chromosome location of a recessive gene for leaf rust resistance from Triticum carthlicumPs5 Evaluation and Utilization of the Resistance of Amphiploids between Triticum and Aegilops Species to Wheat Diseases