Breaking seed dormancy in Cupressus atlantica Gaussen,an endemicand threatened coniferous tree in Morocco  

作　　者：Sfairi Youssef Ouahmane Lahcen Abbad Abdelaziz 

机构地区：[1]Direction Provinciale des Eaux et Forets et de la lutte contre laDésertification,Marrakech,Maroc [2]Laboratoire de Biotechnologies,Protection et Valorisation des Ressources Végétales,département deBiologie,Equipe de Phytochimie et Pharmacologie des Plantes Aromatiques et Médicinales,Facultédes Sciences Semlalia,UniversitéCadi Ayyad,Marrakech,Maroc [3]Centre Régional de Recherche Forestière,Circuit de la Palmeraie,Marrakech,Maroc [4]Laboratoire de Biotechnologies,Protection et Valorisation desRessources Végétales,département de Biologie,Equipe de Phytochimieet Pharmacologie des Plantes Aromatiques et Médicinales,FacultédesSciences Semlalia,UniversitéCadi Ayyad,Marrakech,Maroc

出　　处：《Journal of Forestry Research》2012年第3期385-390,共6页林业研究（英文版）

摘　　要：Cupressus atlantica Gaussen （Cupressaceae） is an endemic and endangered coniferous tree geographically restricted to the N＇Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improve seed germination, different pre-treatments were conducted on C. atlantica seeds after storage for different periods （one, two and five years） including： scarification with sandy paper; soaking seeds in hot distilled water at 60℃ and 80℃ for 15 min and soaking seeds for 48 h in a gibberellic acid （GA3） at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially an exogenous dormancy （physical dormancy） due to the hard seed coat （hardseededness）. Exogenous application of gibberellic acid （GA3） at 1,000 mg.L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination （8-10 days） and low values of mean germination times （MGT）. However, germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value, suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the ex-situ conservation of such endemic and endangered species where the production of seeds is irregular over the years.Cupressus atlantica Gaussen （Cupressaceae） is an endemic and endangered coniferous tree geographically restricted to the N＇Fis valley in South-Western Morocco. Like many forest species, C. atlantica exhibits dormancy which delays and reduces germination. To improve seed germination, different pre-treatments were conducted on C. atlantica seeds after storage for different periods （one, two and five years） including： scarification with sandy paper; soaking seeds in hot distilled water at 60℃ and 80℃ for 15 min and soaking seeds for 48 h in a gibberellic acid （GA3） at 1,000 and 2,000 mg·L-1. Results showed that scarification with sandy paper increased the germination rate of Atlas cypress by up to 67%, indicating that the species possess essentially an exogenous dormancy （physical dormancy） due to the hard seed coat （hardseededness）. Exogenous application of gibberellic acid （GA3） at 1,000 mg.L-1 was also effective in breaking seed dormancy and germination induction. These two treatments induced faster speed germination expressed by low number of days to first germination （8-10 days） and low values of mean germination times （MGT）. However, germination rate, under any treatment, is greatly dependent on the year of seed collection. Seeds collected in year 2004 gave the highest value, suggesting that even after five years of storage, the germination capacity of C. atlantica seeds could remain high. This observation is very interesting in the ex-situ conservation of such endemic and endangered species where the production of seeds is irregular over the years.

关 键 词：Cupressus atlantica ENDEMIC ENDANGERED breaking seed dormancy germination capacity hand scarification ex-situ conservation 

分 类 号：S791[农业科学—林木遗传育种]