Chemotaxonomical and Palynological Studies on Nine Acacia Species Occurring in Sudan

Abstract

The present study was carried out on the chemotaxonomy and palynology of nine Acacia species occurring in Sudan. It included a preliminary phytochemical screening of the flowers extracts using thin layer chromatography (TLC) followed by isolation of the major compounds from A. nilotica flowers. Palynological results showed that the studied species, except for A. laeta, can be divided into two types; Type 1 pollen characterized by spinescent stipules and Type 2 pollen typified by non-spinescent stipules. A. laeta, in addition to all characters of Type 2 pollen, has polyads with 18-20 monads, a fact supporting its hybrid origin. TLC of extracts revealed the presence of phenolic substances with selective reactivity towards phenolic detectingreagents. TLC comparison of the isolated compounds with extracts from studied species revealed that gallic acid and its methyl ester were only persistent in Acacia species exhibiting spinescent stipules. Thus, suggesting their use as good chemotaxonomic markers.