Geographic variation in seed, leaf and seedling traits of wild almond (Amygdalus scoparia Spach.) in Fars province

Abstract

Knowledge about geographic variation within the native range of forest tree species is the logical first step in genetic studies. Wild almond (Amygdalus scoparia Spach.) is a multi-purpose species with a widespread geographic distribution in most of the vegetation regions of Iran. In order to study the geographic variation of wild almond, nineteen biometric features of seed, leaf and seedling from seven natural population of this species in Fras province were measured. Significant differences were observed among the populations for all of the studied characteristics. Hundred seed weight, leaf area and number of stems showed maximum variation among the studied traits. Seed traits presented a significant positive correlation in terms of mean annual rainfall. Correlation analyses between biometric traits and geoclimatic factors indicated the existence of clinal variation in some seed, leaf and seedling traits. Seedling leaf morphometric (dimension) traits decreased gradually from north to south populations; while seedling height declines from east to west populations. That means the geographic variation of the plant at the seedling stages reveals a two- way variation with the latitude and longitude. Principal component analysis (PCA) and cluster analysis of data revealed four distinct groups of populations, and separated populations of high rainfall area form that of lower rainfall area. Results also revealed that A. scoparia uses adaptive strategies in response to water deficit.

Keywords

• Biometric traits
• clinal variation
• intra-specific variation
• provenance