Induction of mutation in the west Australian Blue Lupin (Lupinus digitatus forsk) by X-irradiation

Abstract

Dry seeds of Lupinus digitatus Forsk. were given X-ray doses ranging from 10 to 125 kr. The highest doses tolerated were between 70 and 90 kr, but for the practical induction of mutations the optimum range is probably 40–60 kr or less. Altogether 132 mutations were recorded. One of these, an early-flowering mutant, could be of value. Nearly all the milder mutations segregated as simple recessives, but there was at least one dominant. Many of the more drastic mutations segregated irregularly. The progenies of individual X₁ inflorescences were sown separately in the X₂, and the pattern of appearance of mutations showed that, whereas the seeds produced in most individual X₁ branch inflorescences were descended from a single cell in the irradiated seed, those in the apical inflorescences were often descended from two or more cells. In very few cases were all the seeds of an X₁ plant found to be descended from the same original cell.