Figure 1.

Germination physiology and temperature responses of Chenopodium album dimorphic seeds. (A) Seed dimorphism and temperature profile of C. album seedlot #1 maximum germination percentages (G_max). The G_max comparison at the temperatures indicated of mature freshly harvested (FH) black and brown seeds and after-ripened (AR) seeds imbibed at 24°C. (B) The effect of cis-S(+)-abscisic acid (ABA) at 24°C and of cold temperature (12°C) on the time courses of testa rupture (TR) and endosperm rupture (ER). (C) Physiological stages and visible events during the germination and subsequent seedling growth of C. album dimorphic seeds. (D) The kinetics of germination (scored as ER over time) of seedlot #1 seed morphs at different temperatures. (E) Seed dimorphism and temperature profile of C. album seedlot #2 G_max. (F) Control of visible events (TR, ER) during C. album germination and the effects of light, cold, nitrate and hormonal (ABA; GA, gibberellins; C₂H₄, ethylene; CK, cytokinins) treatments (this work and Karssen, 1976a; Karssen, 1976b); drawing of seed stages from (Karssen, 1976b) reproduced with permission. (A-F) Mean ± SEM values are presented of at least 3 petri dishes each with 30 seeds imbibed in continuous white light.