Effects on growth and development of individual chromosomes from slow-growing Lophopyrum elongatum Love when incorporated into bread wheat (Triticum aestivum L.)

Aspects of growth and development were evaluated in the fast-developing ann ual Triticum aestivum L. 'Chinese Spring', the slow-developing perennial Lo phopyrum elongatum Love, their amphiploid, and chromosome addition and subs titution lines of L. elongatum into 'Chinese Spring'. Relative growth rates (RGR) of shoots of L. elongatum and the amphiploid were lower than those o f 'Chinese Spring' (34 and 13 % respectively) and main stein development wa s also slower. There was no difference in shoot RGR of any of the chromosom e addition or substitution lines and that of 'Chinese Spring' when assessed between Haun stages 2.0 and 5.0. In contrast, several aspects of plant dev elopment were observed to differ in the chromosome addition and substitutio n lines. Substituting E genome chromosomes (with the exceptions of 3E and 4 E) for D genome chromosomes, or adding E genome chromosomes, slowed the rat e of main stem development, at least up to Haun stage 5.0. Despite these di fferences in the rate of main stein development, the appearance of adventit ious roots commenced at approximately Haun stage 2.0 in all genotypes. Howe ver, the numbers of adventitious roots and tillers at the 5.0 Haun stage di ffered between some of the lines when compared to 'Chinese Spring'. Althoug h incorporation of some L. elongatum chromosomes altered aspects of plant d evelopment, all lines showed more similarity to bread wheat than to L. elon gatum, reflecting, in part, the greater genetic contribution made by bread wheat to these lines. (C) 2001 Annals of Botany Company.