Weedy Adaptation in Setaria spp.: VIII. Structure of Setaria faberi Seed, Caryopsis and Embryo Germination

TL;DR

This study investigates the germination process of Setaria faberi seeds, revealing how embryo axes grow independently and how germination states vary, which aids in understanding seed survival strategies in changing environments.

Contribution

It introduces a new framework for classifying seed germination states based on embryo growth, highlighting the independent behavior of embryo axes in Setaria faberi.

Findings

Embryo axes grow independently during germination.

Germination states can be categorized into three levels for each axis.

Seeds exhibit diverse germinability states, aiding survival in variable conditions.

Abstract

Giant foxtail (Setaria faberi) seeds differ in requirements for germination. Variable germinability arises during seed development under the influence of genotype, environment and parent plant. Giant foxtail seed germination has been shown to be regulated by independent asynchronous or dependent synchronous action of seed structures. To gain better insight into the process, germination was divided into axis specific embryo growth categories or states. Three states were defined for each embryonic axis. The degree of embryo growth (germination state) after eight to twelve days under germination conditions is believed to reveal the germinability state (potential for germination) possessed by the seed before germination. The embryo axes behave independently, which allows any combination of germination states to occur. In general, the greater the difference in germination between the axes, the less likely the combination of states will occur. Photographic evidence of each germination state is shown for caryopses and seed. Seed with a variety of germinability states is a strategy for surviving variable environments.