Artificial Mutagenesis in Plant Breeding

Abstract

MANY difficulties and disadvantages are involved in undertaking a programme of improvement of crop plants by the artificial induction of mutations. Among those which have been recognized are (a) the necessity for screening very large populations of plants ; (b) the considerable degree of sterility found in mutant material; (c) the inefficiency of existing mutagens, and (d) in inbreeding forms, the desirability of isolating the frequently male-sterile R ₁ generation, to avoid contamination with foreign pollen. The first of these difficulties is less troublesome in certain instances, as for example, when screening seedlings for disease resistance, for large numbers are easily handled. No doubt, for this reason, many reports¹ of the successful induction and selection of disease resistant mutants do in fact exist; resistance to Erysiphe graminis f. hordeii in barley, to Puccinia glumarum and Puccinia graminis f. tritici in wheat, and to Puccinia graminis f. avenae in oats, are among the most important.