Radiation induced asynaptic mutations in durum wheat (Triticum durum DESF.)

The cytological behaviour and the inheritance of two asynaptic mutations independently obtained by neutron treatment of durum wheat seeds of var. Cappelli and Aziziah are considered. Mutant individuals of both lines have normal morphology, but are completely sterile. Analysis of chromosome behaviour at the several stages of PMC meiosis has been thoroughly accomplished in mutant progenies of both varieties during two subsequent generations. A completely random chromosome disjunction was found at anaphase I, together with multipolar spindles, laggard chromosomes etc. At meiotic second division a large amount of abnormalities were found, as a consequence of previous asynapsis and irregular polarization. Some differences in cytological behaviour were found between the asynaptic mutants of Cappelli and the asynaptics of Aziziah. - Genetic analysis demonstrated that both mutations behave as monogenic recessives.Contribution No. 139 from the Laboratory for the Application of nuclear energy to Agriculture, Casaccia Nuclear Studies Centre, Roma, Italy. - Part of the investigation was supported by Consiglio Nazionale delle Ricerche (Gruppo di lavoro per il miglioramento genetico delle piante erbacee e cultivate, Sottogruppo per il grano duro).