Figure 8.

Chenopodium album dimorphic seed GA/ABA ratios and comparison of Amaranthaceae testa thicknesses and dry seed hormone contents. (A) Germination time courses and bioactive GA/ABA ratios of seedlot #1 black (after-ripened) and brown seeds imbibed at 24°C. (B) Germination time courses and bioactive GA/ABA ratios of seedlot #2 dimorphic seeds imbibed at 24°C. Mean ± SEM values are presented. The thermal-time constants Θ_cold(50%) ± SD from the population-based threshold modeling ( Supplementary Figure 1 ) are indicated and those of seedlot #1 are similar to Chenopodium quinoa (141-152 °C•d-1 from Ceccato et al., 2015). (C) Germination time courses and bioactive GA/ABA ratios of seedlot #1 black (after-ripened) imbibed at 12°C and 24°C. (D) Comparisons of C. album seed mass and testa thickness of the dimorphic seeds of seedlots #1 and #2 (this work) with published work: CHEAL (Gardarin et al., 2010), and LLL, SSS, RRR (Karssen, 1970) (left panel). Comparisons of C. album seed mass and testa thickness with Amaranthus hybridus (Gardarin et al., 2010; Nakabayashi and Leubner-Metzger, 2021) and C. quinoa (Ceccato et al., 2015) (right panel). Note that for C. album seedlots #1 and #2 the D (dormant) refers to the freshly harvested mature seed with full physiological dormancy (non-deep and deep PD; nPD+dPD) for seedlot #1, whereas the ND refers to the 2/3^rd of non-dormant seed with nPD not induced during seed maturation. (E) Comparisons of ABA and GA relations in dry dimorphic seeds of C. album (this work), Suaeda salsa (Wang et al., 2015; Li et al., 2016; Xu et al., 2017), and C. quinoa (Ceccato et al., 2015).