II.6 Genetic effects of gametophyte irradiation in barley.
B. Donini and M. Devreux. Laboratorio per le Applicazioni in Agricoltura del CNEN, C.S.N. Casaccia, S. Maria di Galeria, Roma, Italy and Biology Division of the European Communities, Bruxelles, Belgium.
Spikes of two-rowed naked barley, cv. Leonessa, were acutely irradiated (1500 R, 93R/hr) in the Casaccia gamma field (60Co source) at different developmental stages of their gametophytes. M1 plants were raised following irradiation of male or female gametophyte and both male and female gametophytes. From 6 to 12 spikes for each of the 2961 M1 plants were analysed for chlorophyll and morphological mutation at seedling stage and the 94 segregating progenies showed the presence of mutation in all spikes of the M1 plants. The total mutation frequency, expressed as number of segregating progenies per 100 M1 plants, induced by analysing the whole M2 generation, is 27, 18 and 8 percent respectively after both gametophytes, male and female gametophyte irradiation.
Among the mutants isolated, concerning plant size, number of florets in the spike, seeds size and colour; a very early type (25 days ahead the control) has been multiplied for its agronomic interest.
Supported by sub-contract between Euratom-Ital Association and CNEW.