Errata slip inserted. / Bibliography: leaves 68-93. / viii, 93, [42] leaves, [15] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Rye chromosome 6R in triticale contains a gene useful for resistance to cereal cyst nematode. This study shows that the complex structure of this chromosome may prevent render its use impracticle in introgression of this resistance into wheat. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1998