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Germination percentages were also evaluated in terms of treatments (Figure 2). The highest germination percentage in the greenhouse was observed in seeds collected at third seed collection time and subjected to eight weeks of stratification period after soaking in water for 48 hr without GA3 treatment (95 %). GA3 treatment and soaking of unstratified seeds in water for 48 hr didn’t have any positive effect on germination value. DISCUSSIONS RASPRAVA In this study, cold-moist stratification period was determined as eight weeks for Acer cappadocicum seeds in the preliminary trials. When the stratification period was prolonged, most of the seeds germinated during stratification period. Yahyaoglu et al. (2006) reported that seed germination during stratification period was an important factor in obtaining low germination in sowing. Because of this reason, stratification process should be continued to species requiring stratification period before germination process until the first germinant appear in stratification medium. Because, the germination of the seeds in stratification medium affected germination percentage negatively. Urgenc (1998) also reported that stratification period could extend from one week to 3-4 weeks or even longer depending on the species. If startification period extend, the seeds could begin to germinate during stratification medium. This situation was detected in some Maple species ( Urgenc 1998; Piotto and Noi 2001; Bonner and Karrfalt 2008). The germination percentage of Acer cappadocicum seeds stratified for eight weeks was higher than seeds unstratified in both the growing chamber and the greenhouse conditions. This result underlines the fact that seeds of Acer cappadocicum exhibit physiological dormancy and require stratification period to overcome seed dormancy. Several researches have already investigated that some maples had seed dormancy and mature Acer seeds require at least eight weeks of cold moist stratification to overcome dormancy (Urgenc 1998; Macdonald 1999; Piotto and Noi 2001; Nasari et al. 2018). However, it is also stated that stratification period should be longer in order to break dormancy in seeds of Acer saccharum (Evans and Blazich 1999), five different Acer species (Yang and Lin 1999), Acer ceasium (Phartyal 2002). Also, Farhadi et al. (2013) pointed out that the highest germination value of Acer velutinum seeds was obtained after 16 weeks of cold-moist stratification. Furthermore, unlike the present study, Yılmaz (2007) reported that the dormancy of Acer trautvetteri seeds was completely removed by three months of chilling but all seed germinated during the chilling period. Therefore, in the present study, stratification period was suggested as eight weeks because of this sitution can be cause failure in sown. In this study, it was determined that soaking unstratified seeds in water for 48 hr before germination trial was no statistically significant effect on germination. However, when treatments evaluated on the basis of indivudual, the highest germination percentage in the greenhouse was obtained from seeds collected at third seed collection time and subjected to eight weeks of stratification period after soaking in water for 48 hr without GA3 treatment (95 %) (Figure 2). Smilarly, after moist chilling for 16 weeks of seeds after soaking 48 hr in water and germinating at 5:15 0C, germination was 92 % in Acer pensylvanicum (Bourgoin and Simpson 2004). Furthermore, it was observed that soaking different Acer seeeds in water for 48 hr before germination trials increased germination rate (Webb and Dumbroff 1969; Webb 1974; Genc 2007 ). According to analysis of variance (Table 2), it was found out that GA3 treatment had a significant effect on germination in growth chamber (+ 5 0C) but there wasn’t any difference between GA3 doses (Table 3). Smilarly, Pawlowski (2009) reported that breaking of dormancy was stimulated by Gibberellic acid in Acer platanoides seeds. GA3 treatments of Acer hyrcanum seeds shortened the cold stratification period and increased germination but did not eliminate the requirement of cold stratification of the seeds (Naseri et al. 2018). In this study, it was found out that GA3 treatment didn’t have a significant effect on germination in greenhouse conditions. As a result of sowing in the greenhouse, it was observed that GA3 treatment was less effective than cold moist stratification treatment for 8 weeks on the germination of the seeds. These results indicate very clearly that GA3 treatment of Acer cappadocicum seeds especially stratified before sowing in greenhouse doesn’t have a positive effect on germination. Therefore, GA3 application should not preffered in the greenhouse sowing of Acer cappadocicum seeds. Similarly, Stejskalova et al. (2015) found out that in Acer pseudoplatanus gibberellic acid did not increase the germination percentage compared to stratified seeds. Furthermore, Webb and Wareing (1972) reported that GA3 treatments had no effect for breaking dormancy in Acer pseudoplatanus seeds. Although growth chamber and green house results both indicated that seed collection time did not seem to play a role as statistically on seed germination, Duncan’s test showed that the third seed collection time was in a different group (Table 5). The reason for this is the sensitivity of the the test. The highest germination (95 %) in the greenhouse was detected in the seeds collected at collection time 3. Also, there was a positive correlation between seed collection time and germination (r=0.442). As a result, the third collection time (in october) should be prefered as seed collection time in Acer capppadocicum seeds, considering that it may vary according to the climatic conditions of the year. ACKNOWLEDGEMENTS ZAHVALA The authors thank Asst. proffesor Aydın KAHRİMAN for valuable comments regarding statistical analysis on the |