Effects on Growth and Development of Individual Chromosomes from Slow-growing Lophopyrum elongatum Löve when Incorporated into Bread Wheat (Triticum aestivum L.)

Aspects of growth and development were evaluated in the fast-developing annual Triticum aestivum L. ‘Chinese Spring’, the slow-developing perennial Lophopyrum elongatum Löve, their amphiploid, and chromosome addition and substitution lines of L. elongatum into ‘Chinese Spring’. Relative growth rates (RGR) of shoots of L. elongatum and the amphiploid were lower than those of ‘Chinese Spring’ (34 and 13% respectively) and main stem development was also slower. There was no difference in shoot RGR of any of the chromosome 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 development were observed to differ in the chromosome addition and substitution lines. Substituting E genome chromosomes (with the exceptions of 3E and 4E) for D genome chromosomes, or adding E genome chromosomes, slowed the rate of main stem development, at least up to Haun stage 5.0. Despite these differences in the rate of main stem development, the appearance of adventitious roots commenced at approximately Haun stage 2.0 in all genotypes. However, the numbers of adventitious roots and tillers at the 5.0 Haun stage differed between some of the lines when compared to ‘Chinese Spring’. Although incorporation of some L. elongatum chromosomes altered aspects of plant development, all lines showed more similarity to bread wheat than to L. elongatum, reflecting, in part, the greater genetic contribution made by bread wheat to these lines.