SEED-BORNE FUNGI IN RELATION TO COLONIZATION OF ROOTS

Abstract

As part of a study of the microflora developing on plant roots, analyses were made of the fungal populations of non-sterilized barley, flax, and wheat seed and of their primary roots 2 days after seeding in natural soil and at short intervals thereafter over a period of 3 weeks. It was found that fungi associated with the seed played little part in the colonization of roots in the soil. Species of Aspergillus, Penicillium, and Alternaria, abundant on the seed, were rarely obtained from root samples. The young roots (2 days after seeding) were relatively free from fungi; however, those which were colonized at this time yielded species of Pythium and Fusarium predominantly. In subsequent samples the percentage incidence of Pythium declined markedly, the predominating types being species of Fusarium, Phoma, Pullularia, Periconia, and Cylindrocarpon, the latter genus assuming greater prominence on wheat than on either barley or flax.