Effect of light, temperature and different pretreatments on seed germination of Gentiana boissieri schott et kotschy ex boiss. (Gentianaceae) an endemic to Turkey

This study was undertaken with the aim of determining the germination characteristics of Gentiana boissieri (Gentianaceae), an endemic species. The effects of light, temperature and different pretreatments on the germination of seeds collected from nature were investigated. Two different experiments were run to determine germination characteristics of seeds and the final germination percentage (FGP), mean germination time (MGT) and germination index (GI). The first experiment involved twenty different treatments including soaking in water, soaking in gibberellic acid (GA3), dry stratification, moist cold stratification, moist warm stratification + moist cold stratification, moist cold stratification + soaking in GA3 and control. The germination test was carried out at +20°C in dark. The highest final germination percentages were obtained from the treatments of soaking in 500, 750, 1000 ppm GA3, soaking in 250, 500 ppm GA3 + 4 weeks of moist cold stratification (89.00; 95.00; 93.50; 91.33; 94.00%, respectively). In the control group with no pretreatment, the final germination percentage of seeds was found to be 13.50%. In the second experiment, seeds treated with 750 ppm GA3 pretreatment, providing highest germination rate in the first experiment, were germinated under dark and light conditions (12/12 h; dark/light) at 15, 20, 25 and 10/20°C. At the end of 28 days under four different temperatures, it was found that light significantly increased the final germination percentage and the highest final germination percentages were found at 15 and 20°C (87.00; 89.50%, respectively). © 2017, Pakistan Botanical Society. All rights reserved.112O060This study was carried out with the support of ?The Scientific and Technological Research Council of Turkey (Project No. 112O060)?. Species identification was made by Assoc. Prof. Emine Al??tepe. -