p. salehi shanjani

Achillea tenuifolia Lam. belongs to the Asteraceae family that is one of the most popular aromatic plants in Iran with great variation in both morphology and essential oil components. The aim of this study was determination of essential oil content and composition of A. tenuifolia populations in field condition. Seeds of 17 populations of A. tenuifolia collected from their natural habitats were cultivated under the same environmental conditions in the research farm of Alborz Research Station, Karaj, Iran. The aerial parts of the plants were collected at full flowering stage and dried in shade (room temperature) and their essential oils were obtained by hydro-distillation. The oils were analyzed by GC and GC/MS. Based on the results, the oil yield varied from 0.16 to 1.59% (w/w dried weight). Populations from Divandareh with 1.59% and Khoy2 with 0.16% had the highest and lowest oil yield, respectively. According to the cluster analysis, the populations were placed in two clusters. Germacrene D was the main compound in all oils, but the essential oils of populations in cluster 1 contained higher amount of germacrene D (up to 64.5% in Semnan population). α-Humulene (up to 15%) and 1,8-cineole (up to 11.7%) were the other major components in the oil of cluster 1 populations. The lower amounts of these three compounds (in addition to E-β-farnesene and piperitone) and higher amount of more volatile compounds like p-cymene, β-phellandrene, camphor, and α-thujone and presence or absence of other minor compounds placed the other populations in cluster 2. Each cluster divided in two groups because of different percentages of some component such as cubenol, viridiflorol, methyl hexadecanoate and phytol. Therefore, based on the demand for processing, the proper population can be chosen for vast cultivation.

Evaluation of necessary and sufficient population number of a species in seed collection program requires knowledge of genetic diversity and differentiation. This study evaluated seed morphology and seed storage proteins profiles of 11 boxwood (Buxus hyrcana) populations, to determine the extent of genetic diversity. Seed morphology and seed storage proteins analysis of variance showed considerable variation with no geographical clines among populations. Hierarchical cluster analysis (UPGMA) of both markers showed that populations sampled from far west (samandkish, Gilan province) and far East (Bandargaz, Glestan province) of Hyrcanian forests were grouped together, however neighbor populations, Namakabrud1 and 2, grouped separately. The results could be due to the phenomenon of fragmentation of boxwood populations. Therefore seed collection from selective populations can lead to the loss of some genes and change genetic structure, indicating the importance of collecting seeds from local ecotypes. In other word seed collection only from a population in each Eco-geoghraphial region is not sufficient and often the populations that located in a same Eco-geoghraphial region may have different genetic structure. These results showed that to avoid genetic erosion of boxwood germplasm, Natural Resources Gene Bank of Iran needs to collect seed from more populations in each Eco-geographical region.

Reforestation with autochthonous species should take into account the preservation of the temporal variability and the geographic structure of genetic diversity in forest species. In order to provide empirical data about the suitability of methods of sampling material, genetic comparison of 10 beech populations (at least 40 trees per population) and their progenies (seeds of 10 mother trees per population, each tree 7 seeds) were analysed using four highly polymorphic microsatellite loci. The allelic multiplicity was higher in seed samples than adult trees indicating gene flow from adjacent plant populations. The comparison for genetic diversity measures between adult trees and seed generation revealed no significant differences for allelic richness (Na), effective number of alleles (Ne), and number of rare alleles (Nr), neither observed (Ho) nor expected heterozygosity (He). Genetic differentiation in allelic frequencies between adult trees and seeds generation were rather low (Fst = 0.058). A close genetic relationship between adult trees from seed generation of each population, which revealed by un-weighted pair group method based on arithmetic average (UPGMA) and supported by an analysis of molecular variance (AMOVA), were detected. In this paper some aspects related to seed sampling were discussed