Mutation breeding of rubber plant

Irradiation using gamma rays from 60Co at 1000 rad was done to brown budwood of GT 1 and PR 255, to obtain mutants resistant to mildew and black stripe diseases. Different morphological anomalies were found, among others regarding the number and thickness of leaves, slow growth, blind terminal buds with a long patiole and twisted leaflets. To stimulate growth of mutated cells, the shoots were cut at a height of 4.8 and 12 buds counted from the base of the shoots. New shoots grew as the result of this cutting, which later will be budded for a testing against disease resistence in the nursery. (author)