Impact of long-term storage on the germination of turkish pine (Pinus brutia Ten.) seeds

Considering the intensive artificial and natural rejuvenation studies and forest fires affecting red pine species in our country, it is of great importance to store the improved seeds for many years without compromising their quality. Temperature, storage time, relative humidity, storage method, seed moisture content, and the amount of fungal inoculum in the seeds are factors that affect seed storage. This study investigates the effect of long-term storage on red pine seeds. For this purpose, red pine seeds obtained from seed orchards representing five different origins (Gündoğmuş, Kaş, Kesmeçay, Bucak, and Serik) between 1997 and 2017 were used. After the seeds were obtained, they were stored under the same conditions in the cold storage of Antalya Forest Nursery. In the selection of origins, care was taken to represent different altitudes and climatic zones. In the research, 1000 grain weight and seed moisture percentage were determined in seeds belonging to different storage years, and then germination tests were carried out. Germination tests were completed in an incubator at 25°C in 28 days. Before the tests, the seeds were surface sterilized. After the germination tests, the germination percentages (GP) and mean germination times (MGT) of the seeds were calculated. At the end of the study, it was determined that the 1000-grain weight values of the seeds were close to each other by years, the average 1000-grain weight was 56.19 grams, the minimum 1000-grain weight was 46.1 grams, and the highest 1000-grain weight was 63.43 grams. The moisture percentages of the origins generally increased over the years due to storage conditions. The average seed moisture percentage in the origins was determined as 11.56%, but in some origin and storage years (Kesmeçay 2014, Serik 2012, and Gündoğmuş 2013), the seed moisture percentages were found to be above 12%. When evaluating the overall effect of the storage period on the germination percentage (GP) and mean germination time (MGT) values of red pine seeds from different origins, it was observed that the GP values decreased with increasing storage period, while the MGT values increased. However, in some origins, the GP values remained the same in terms of storage time, while some MGT values decreased. Considering all the origins and storage years, the average germination percentage (GP) was 75.98% and the mean germination time (MGT) was 15.82 days in red pine seeds stored for 4-23 years. When all of this data is evaluated together, it can be concluded that red pine seeds can be stored for up to 20 years under appropriate conditions.