Comparison of Seed Characteristics in Even-aged Accessions of Atriplex canescens under Exclosure and Non-exclosure Conditions in Rangelands of Zarand-Shahriar, Iran

To compare the seed characteristics in accessions of Atriplex canescens under exclosure and non-exclosure conditions, two even-aged sites were selected with an area of 400 ha as the exclosure and 1000 ha as non-exclosure area. To conduct the study, 30 species were randomly selected in autumn 2009 in reference area of the sites and seeds were collected. Some important seed characteristics were studied in the laboratory. Data analysis was conducted using SPSS 17 software and mean comparisons were performed by Duncan''s Multiple Range Tests. Results showed that the winged seeds did not germinate under all studied treatments in both sites. Moreover, maximum seed germination was recorded for the seeds soaked in cold water for 24 hours and placed in the shade for 48 hours. According to the results of the independent t-test, no significant differences were observed for germination percentage, germination rate, and vigor index in both sites at both 1 and 5% probability levels. In other words, the seeds collected from the exclosure and non-exclosure areas were similar in terms of the mentioned characteristics. However, seed yield, 1000-seed weight and seed moisture content showed significant differences at 1% probability level with higher amount in exclosure area.