Effects of Environment on the Metabolism and Germination of Crested Wheatgrass Seeds

Abstract

Seeds of crested wheatgrass (Agropyron desertorum [Fisch. ex Link] Schult.), planted at a depth of 1 inch, germinated well because of relatively constant and favorable moisture conditions. These seeds rapidly synthesized hexose phosphate, uridine diphosphate hexose, nicotinamide adenine dinucleotide, adenosine diphosphate, adenosine triphosphate, and other phosphate esters. Synthesis began 2 to 4 weeks before germination was observed. In contrast, seeds on the soil surface failed to germinate because of generally unfavorable and rapidly fluctuating moisture conditions. Adenosine triphosphate, the principal phosphate ester formed in these seeds during brief periods of precipitation, was broken down during periods of drought. Although these measurements include only a few of the biochemical reactions that occur in seeds, they contribute to an understanding of the environmental conditions that promote or retard germination processes and help explain the reasons for success or failure of seedings on semiarid rangelands.