Effect of moist chilling treatment on seed germination of 7 species of Anthemis and Tanacetum

Two genera of chamomile and tansies (Anthemis and Tanacetum) belong to asteraceae family are widely used as medicinal plant possessing several pharmacological effects due to presence of active compounds. One of the main problem in maintenance seeds of wild and native species in gene bank is regeneration of aged seeds that lose their viability over times. For increasing of seed germination percentage (G%), it is necessary to apply some seed dormancy breaking treatments. In this experiment seeds of 19 accession from seven species of A. altissima, A. haussknechtii, A. tinctoria, A. triumfettii, A.pseudocotula, T. parthenium and T. pinnatum were provided from Iranian natural resource Research Institute of Forests and Rangelands, Tehran in 2014-2015. Seeds of A. altissima were storage for 18 years and seeds of other species were storage in range of 9-14 years as medium-term storage (active cold room 4°C). The initial seed G% was also provided from gene bank. Seeds of 7 species were evaluated using 5 x7 factorial based on completely randomized design with four replications. The five levels of chilling treatments were initial G%, (control), 1 month and 2 months moist chilling (4°C) and field establishment. Result of analysis of variance showed that there is a significant effects between species, treatment (P<0.0) and their interactions (P<0.05). Results showed that both moist chilling had significantly increased G% in all of species than that for both initial G% and control G%. The 1 month moist chilling treatment had significantly increased total G% with average values of 24.7 % than that for control (6.2%). The lowest G% was obtained in A. altissimo. This species was kept for longer time (18 years) in gene bank, indicating the effect of long time storing in seed derogation. The effect of chilling treatment on G% was higher in A. altissima, A.triumfettii,T.parthenium than other species. It was concluded that 1 month moist chilling is suggested for dormancy breaking of chamomile and tansies