Effect of Physical Treatments on the Promotion of Seed Germination in Green and Giant Foxtails

Inagaki Hidehiro,Sakakibara Takumi

doi:10.3844/ajabssp.2020.126.131

Abstract

The difficulty of breaking seed dormancy in Setaria (foxtail) species presents a problem in using them as model plants. In the present study, we observed the structure of the seed coat surface of two Setaria species, the green foxtail (Setaria viridis) and the giant foxtail (Setaria faberi), using an electron microscope. In addition, we tested the effects of physical treatment on Setaria seeds using four treatments: (1) Removing the outer seed coat, (2) removing the outer seed coat + mechanical scarification of the inner seed coat (the seeds were scarified using sand-paper with grit 350-2000), (3) removing the outer and inner seed coat and (4) No treatment (control). During the observation using electron microscope, we found a structure that was supposed to repel water (which is called the ‘lotus effect’). We found that seed germination in Setaria species can be induced by removing the outer seed coat along with mechanical scarification of the inner seed coat (second treatment) as well as by removing the outer and inner seed coat (third treatment), whereas seed germination was not observed after removing only the outer seed coat and no treatment.

Highlights

Climate change is a great problem throughout the world, which is why C4 plants, which perform C4 type photosynthesis and exhibit high photosynthetic ability under conditions of high temperature, dryness and strong light in the summer, are increasingly drawing attention as climate change-tolerant species
We studied the surface structure of Setaria viridis and S. faberi seeds and we investigated the effects of four different physical treatments on the germination of their seeds
The difficulty of breaking seed dormancy is a problem for their use as model plants

Summary

Introduction

Climate change is a great problem throughout the world, which is why C4 plants, which perform C4 type photosynthesis and exhibit high photosynthetic ability under conditions of high temperature, dryness and strong light in the summer, are increasingly drawing attention as climate change-tolerant species. The green and giant foxtail are annual Poaceae weed species (GRIN, 2020) which possess some weed characteristics (i.e., ‘weediness’), such as rapid growth, small plant size at the seed setting stage, prolific seed production and short life cycle (Baker, 1974). These characteristics are problematic for weed removal but are ideal for the use of these species as model plants (Sebastian et al, 2014). Such difficulty in breaking seed dormancy makes them extremely inconvenient for use as model plants (Manthey and Nalewaja, 1987; Liu et al, 2003; Sebastian et al, 2014)

Methods

Results

Conclusion