| A dominant short straw mutation induced by thermal
neutrons in durum wheat.1) A. BOZZINI and G. T. SCARASCIA-MUGNOZZA Laboratorio per le Applicazioni in Agricoltura del CNEN, CSN Casaccia, S. Maria di Galeria, Rome, Italy Among several short straw mutants isolated in the cv. Cappelli (SCARASCIA-MUGNOZZA, 1965) a thermal neutron (8.38 x 1012/cm2) induced mutant line (Cp B 132) demonstrated a good yielding ability, a better utilization of nitrogen manuring and an improved lodging resistance (SCARASCIA-MUGNOZZA et al., 1965 ; CAVAZZA et al., 1967). Genetic analysis of this mutation showed that when the mutant line is crossed to the mother line Cappelli, the F2 shows a distribution of heights indicating a monofactorial dominant behaviour of the mutation. In Table 1, the height distribution of parents, of F1 individuals and F2 progeny, is presented. Chi square analysis of segregation (173 tall; 48 short) gave a value of 1.27, corresponding to a P value between 25 and 30 % for a 3:1 hypothesis. Further genetic analysis will confirm such a behaviour, but preliminary data obtained from crosses of the mutation to several other durum lines and varieties, seem to confirm its dominant and monofactorial condition. As far as we are aware, this is the first case of a dominant mutation strongly reducing plant height (to about 80-85 % of control) in Triticum durum which keeps a normal viability and good agronomic characteristics. The dominant behaviour of the mutation, if confirmed, will allow its easy transfer to other lines by backcross procedures and may find utilization in hybrid wheat production. (Received Feb. 7, 1967) |
| 1) Contribution n. 148 from the Laboratorito per le Applicazioni in Agricoltura del CNEN, CSN Casaccia, S. Maria di Galeria, Roma, Italy. |