Normalized Seed Weight of Three Species of the Genus Peganum L. (Peganaceae Van Tieghem) in Mongolia

Abstract

Variation of seed weight of Peganum species is positively correlated with mean seed weight in big populations. It was insignifi cant in small populations, suggesting normalized seed weight is useful to distinguish the population sizes. Normalized seed weight is increased with increasing aridity index and precipitation amount in most sites. Within populations of Peganum harmala , variation of seed weight and normalized seed weight corresponded to Nei’s diversity index, while within other species, mean seed weight corresponded to Nei’s diversity index. The normalized seed weight was lowest in human-dispersal species, highest in hydro-dispersal species, but it was moderate in wind-human-dispersal species. Low normalized seed weight is associated to species with low genetic diversity, while high normalized seed weight to species with high genetic diversity. Variation of seed weight was related with precipitation and climatic aridity and genetic diversity within species and mean seed weight was with climatic aridity and genetic diversity within species, but normalized seed weight was related with precipitation, climatic aridity and genetic diversity inter- and within species

Keywords

• variation of seed weight
• mean seed weight