[The effect of some treatments on the germination of Mahaleb (Prunus mahaleb L.) seeds and its seedlings growth]

Prunus mahaleb L. has the ability to grow on poor and lime soils and bare rocky slopes , and has the resistance to some disease .Therefore It has a big importance as rootstock for cherry trees and afforestation of the arid regions . Seeds have two types of dormancies; endocarp and embryo dormancy .this reduces the percentage germination and to overcome dormancy seeds are sown in autumn (in some nurseries) , seeds by this way most of the time need more than five months to be germinate . This experiment was carried out in 2007on March and 2008 on February and March . effect of some treatments on the germination of Prunus mahaleb L. wherefrom percentage , speed and homogeneity germination and the final length of the seedlings were studied in the aim of overcoming dormancy , increase percentage germination and reduce the length of period for germination . seeds treatments were divided into two main groups : with endocarp so that concentrated sulfuric acid (96 %) and expansive (48%) for 10 , 20 , 40 , 80 minute , continues stratification for 10 weeks at 2 _ 4º C and intermittent : 4 weeks at 2 _ 4º C then 2 weeks at 15 _ 20º C then 4 weeks at 2 _ 4º C , sulfuric acid + gibberelline (GA3) 750 , 1000 , 1250 PPM , sulfuric acid + stratification and sulfuric acid + gibberelline + stratification were applied. And the second group without endocarp so that gibberellins , stratification , gibberelline + stratification and water soak for 24 hours . Results showed that the highest percentage germination in 2007 was obtained by treating seeds with endocarp with sulfuric acid 96% for 10 + gibbereline 1250 PPM + intermittent stratification (15.55%) , as to in 2008 was obtained by treating seeds with sulfuric acid 48% for 80 + gibbereline 1250 PPM + intermittent stratification(57%) in February date. the highest percentage germination in 2007 was obtained by removing the endocarp then soaking seed for 24 hours at 1250 PPM gibberelline concentrate (40.89%) and the highest percentage germination in the experiment at all was obtained in 2008 in February date (70%) by the same treatment , it was better significantly than autumn sown in Bet tima agricultural center , and has shortened the period for seed to germinate from 141 to only 30 days . It was concluded that the dormancy in the Prunus mahaleb L. seeds is endocarp (physical) and embryo dormancy since embryo has not matured enough and the possibility of the presence of germination inhibitors in the embryo at the same time .