Figure 2.—

Additive chromosomal dosage effects on stem diameter. (A) Mean stem diameter as a function of the relative dosage of chromosomes 1 and 3. For ease of illustration, all aneuploid plants were classified into four categories, symbolized by the size of the chromosome type character, and depending on whether the dosage of chromosomes 1 and 3 was over-represented (rChrX > 1, large characters) or under-represented (rChrX < 1, small characters). Different letters above the two bars indicate significantly different means for these two populations of aneuploid individuals. Values were considered significantly different when the t-test P-values were <0.05. Standard errors are indicated. (B) Relationship between observed mean stem diameter and stem diameter values calculated using a model that assumes full additivity of the single effects of chromosomes 1 and 3 on stem diameter (see materials and methods for details).