NATURAL AND ARTIFICIAL HYBRIDIZATION OF AVENA SATIVA WITH A. FATUA AND ITS RELATION TO THE ORIGIN OF FATUOIDS

Abstract

The common fatuoid or false wild oat is an aberrant grain type which occurs frequently in cultivated oats. Three theories have been advanced in explanation of the origin of fatuoids, namely, chromosome aberration, gene mutation, and natural hybridization. The third theory has been much criticized in recent years. Observations in Alberta, Canada, indicated the possibility of natural hybridization between Avena fatua and A. sativa being an important factor in the origin of fatuoids. Genetic studies were made of both artificial and natural crosses between A. fatua and A. sativa which indicate the probability that the common fatuoid is a normal Mendelian segregate from the crosses in question. It is believed that more or less complete selective elimination of non-fatuoid segregates can be explained. While the authors believe that natural hybridization is the usual means by which fatuoids originate, they, nevertheless, entertain the possibilities of origin by chromosome aberration or by gene mutation.