Analysis of some plant growth regularsin some medicinal dorment seeds of desert plants in Saudi Arabia.I.Cytokinin content of Rhazya stricta seeds.

Abstract

Three populationsof Rhazya stricta seeds, non stored (1999 collection), short term stored (1998 collectio) and long- term stored (1982 collection) were used to study their endogenous level of cytokinins. Using appropriate internal standards, an HPLC profile revealed the absence of free zeatin in quiescent seeds of all of the R. Stricta seed populations used. Zeatin ribosides predominated other cytokinins in all three types of seeds. trans-zeatin and dihydrozeatin contents were high in the 1998 collection followed by 1982 and 1999 collections. Isopentyladenine was also detected but in very small amounts, in the samples of seeds tested