THE CYTOGENETICS OF A TRITICUM-TURGIDUM X PSATHYROSTACHYS-JUNCEA HYBRID AND ITS BACKCROSS DERIVATIVES

Psathyrostachys juncea (2n = 2x = 14, NN), a source of barley yellow d warf (BYDV) virus resistance with tolerance to drought and salinity, h as been successfully hybridized in its autotetraploid form (2n = 4x = 28, NNNN) as the pollen parent to durum wheat (Triticum turgidum L.). The 2n = 4x = 28 (ABNN) F-1 hybrid has a mean meiotic metaphase-I conf iguration of 20.29 univalents + 0.29 ring bivalents + 3.36 rod bivalen ts + 0.14 trivalents. Spike length, internode length, glume awn length and lemma awn length, as well as the general spike morphology of the F-1 hybrid, are intermediate with those of the two parents. Pollinatin g the ABNN F-1 hybrid has given backcross (BC)-I derivatives of an amp hiploid (AABBNN) that expresses limited self-fertility. BC-2 derivativ es have been obtained from these plants. Direct transfers of useful ge nes from Ps. juncea to wheat would require substantial genetic manipul ation strategies. Both conventional and novel methodologies, which may complement each other, and so facilitate reaching an agricultural obj ective end point, are addressed.