بررسي اثرات درجه حرارت و زمان نگهداري در كاهش قوه ناميه بذر گياه مرتعي Eurotia ceratoides

Study of Effects Time and Temprature on Eurotia ceratoides (L.) C.A. Mey Germination

It is inevitable for the improvement and development of rangelands to conserve and protect range species especially key species and palatable ones. One of the successful projects in rangeland improvement and development is to apply seeding methods. It is very important to have technological knowledge about temperature and appropriate time of seed storage in barn and itʹs relation with surviving the germination capacity. The aim of this study is to determine the effects of time and temperature on Eurotia ceratoides germination. This species regarded as a native plant in southern slop of Alborz Mountain. The seeds were collected from Shahkooh region in Golestan province (Iran). After gathering seeds in the site and separating them from litters and other defect seeds, they were kept in oven at a temperature 30 °C, and then taken out when their humidity was about 7-8 percent. 44 containers, all with their shutters, each filled with 150 random seeds were put in four treatments: 0-5, 5-10, 15, 20°C. Every eleven containers were placed in separate storage areas. Then a germination machine was used to measure the germination capacity with the intervals of (3, 6, 9, 12,..., 30) months. Results showed that all the temperatures had a significant difference at (PO.OOl) and maximum ratio of germination was achieved at 0-5°C during 9 months. The interaction between temperature and time of storage showed that the percentage of germination capacity of the seeds 12 stored till 9 months for temperatures 0-5 and 5-10°C, will increase and then decrease. But in the treatments with 15 and 20°C, with an increase in time of storage, the germination of Eurotia ceratoides will decrease. It seems that though, high temperature is one of the factors that decreases the after-ripening period, in a short time, it has a severe effect on the germination capacity of Eurotia ceratoides. Seeds of Eurotia ceratoides can sustain more than 50% of their germination capacity at temperatures 0-5 and 5-10?C during 2 years.