Abstract
Leucaena leucocephala is a new introduction into Pakistan, as a fast growing tree with many properties of economic importance. In this it was decided to produce some mutants of the species with the help of X-rays radiations, with the object that, (a) any of the mutants may prove to be more suitable and useful than the original parents and (b) the mutants thus raised may provide breeding material to the future breeders. With this object, young seedlings, moist seeds and dry seeds of the species were subjected to the X-rays treatment. The young seedlings died after the treatment, the moist seeds failed to germinate; in both these cases X-rays were lethal enough to cause the death. However, in the third lot where treatment was given to the dry seeds 61% of the seeds germinated, but only 36% finally survived. The surviving 36% exhibited certain morphological anatomical and physiological variations, indicating occurrence of some degree mutation of their genetic material. If these mutants survived, then, in the year to come more variation will appear in them as they will reach maturity. At this stage, it will be quite premature to speculate about their values of economic importance and usefulness, except that they may probably provide genetic material to any of the interested plant breeders in future.