Seed Dormancy and Germination Testing Protocol for Various Economically Useful Plant Species in the Amaranthaceae Family

Abstract

Effective germplasm conservation through seed banking requires that the viability status of every accession in the seed bank be known. This is normally done by conducting a germination test but is, at times, constrained by the presence of seed dormancy in some of the species. While dormancy release protocols have been developed for a majority of species, the same are lacking for others. The objective of this study was to determine the dormancy releasing procedure of selected species in the family Amaranthaceae to develop a germination-testing protocol for them. In this study, the influence of chilling, incubation temperature, potassium nitrate (KNO₃), and dehusking was investigated for 10 wild species. The effect of temperature on seed germination of species in the family was found to be significant (p ≤ .05) with most species performing better at alternating temperatures of 35°C/20°C as compared with constant ones. The effect of dehusking was highly significant on seed germination with the removal of seed covering structures promoting germination in Gomphrena celosioides and Aerva lanata. Application of chilling or KNO₃ treatment as dormancy release mechanisms, while causing a positive effect in some species, reduced germination in others. Out of the 10 species that were investigated in the present study, 6 had their seed-testing protocols successfully developed.

Keywords:

• dormancy
• germination
• seed
• protocol
• viability

The authors would like to acknowledge the Director of the Kenya Agricultural Research Institute (KARI) and the staff of National Genebank of Kenya for their technical and logistical support. The study was funded by the Royal Botanic Garden's Millennium Seed Bank Project through the Seeds for Life Project. This financial support is gratefully acknowledged.