Nobuyoshi WATANABE
Lab. Genetics & Plant Breeding, Faculty of Agriculture, Gifu University Kakamigahara, Gifu, Japan
The competitive ability of certain genotypes will play an important and direct role in the process of differentiation or adaptation to some environments. Under the natural selection, each of AABB genome and DD genome differentiated since the establishment of common wheats.
Tetra Canthatch was reconstituted by KERBER (1964) from Canthatch, a cultivar of common wheat after seven backcrosses to Canthatch of Canthatch-Stewart durum wheat hybrid. Five strains of the resynthesized hexaploid wheat used here were raise by KERBER from the cross between Tetra Canthatcth and each of five strains of Aegilops squarrosa (Table 1).
Considerations of difference of competitive ability between Canthatch and each resynthesized hexaploid wheat make possible to analize the relative contribution among DD genomes in the hexaploidy level.
The competitive ability of each resynthesized hexaploid wheat strain and cultivar Canthatch was tested by comparing the relative response of strains to competitive conditions with a tester variety, cultivar Chinese Spring. Under the competitive conditions, plants of tested strains and those of tester variety were spaced in the row alternatively, that is;
The plants of resynthesized strains were planted on Nov. 15th in 1979 in pure stands and in mixed stands, 10 cm apart in rows spaced 40 cm apart in a split plot arrangement with three replications. Records were taken on ten plants from pure stand and from mixed stands for four vegetative and reproductive characters.