Determination of the seed characteristics of Crataegus monogyna (Pallas ex. bieb) (Oriental Hawthorn) and Crataegus pontica (K. Koch) (East Black Sea hawthorn)

This study was carried out in order to determine the seed characteristics of Crataegus monogyna (Pallas Ex. Bieb) and Crataegus pontica (K. Koch.) and to determine pre-treatments for overcome of germination barriers. The C. monogyna fruit used in the study werwe collected from Hatilla valley – Artvin and C. pontica collected from Pamukçular village –Yusufeli (province of Artvin) in 2016. Seed diameter, seed size, seed weight, moisture content, occupancy rate and thickness of seed coat were taken into consideration as seed characteristics. Pre-treatments used to remove germination barriers are sulfuric acid (H2SO4), floats on water, floats on ash solution, hydrogen peroxide (H2O2), mechanical scarification and some combinations of ash solution and sulfuric acid pretreatments. Sowings were performed according to the 4 replicated random block design. 45 seeds were sown each replication for each pretreatment Studies showed that C. pontica seeds have higher seed coat thicknesses and seed diameter and length than C. monogyna seeds. No germination was observed in C. monogyna seed pretreated with pretreatments of 2 hours of ethyl alcohol, 6 hours of ethyl alcohol and 6 hours of hydrogen peroxide. In addition, germinations were not accrued in C. pontica seeds pretreated with 2 hours of ethyl alcohol and 6 hours of ethyl alcohol. The highest germination percentage was obtained in combination with 74% in the case of C. pontica seeds in combination of 6 hours of sulfuric acid and 6 days in the ash solution pre-treatment, and in the case of C. monogyna species, 26% with combinations of sulfuric acid and 2 hours with ash water solutions pretreatments. The results of the study show that the germination barrier of C. pontica seeds is lower than C. monogyna seeds.