Roles of abscisic acid and gibberellins in maintaining primary and secondary dormancy of Korean pine seeds  

作　　者：Yuan Song Jiaojun Zhu Qiaoling Yan 

机构地区：[1]Qingyuan Forest CERN,Chinese Academy of Sciences,Shenyang 110016,People’s Republic of China [2]CAS Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Shenyang 110016,People’s Republic of China [3]University of Chinese Academy of Sciences,Beijing 100049,People’s Republic of China

出　　处：《Journal of Forestry Research》2020年第6期2423-2434,共12页林业研究（英文版）

基　　金：We thank Kai Yang and Lizhong Yu and Xiao Zheng and Tao Sun for valuable discussion and suggestions about this study.We also thank Hongjun Xu,Jingpu Zhang,Weiwei Zhang and Shuang Xu for fi eld support and technical assistance.

摘　　要：Primary dormancy of seeds of Korean pine(Pinus koraiensis Sieb.et Zucc.)after dispersal in the autumn and the induction of secondary dormancy the fi rst summer following seed dispersal limit the regeneration of mixed broadleaved Korean pine forests in Northeast China.This study was to determine how changes in the levels of abscisic acid(ABA)and gibberellic acid(GA)maintain primary and secondary dormancy of Korean pine seeds under germination conditions.We transferred seeds with one of fi ve primary dormancy states or three secondary dormancy states to germination conditions and measured changes in the levels of ABA,GA 1+3(GA 1 and GA 3)and GA 4+7(GA 4 and GA 7)in the seed coat,megagametophyte and embryo during incubation.Seed coat ABA levels in primary dormant seeds(PDS)and ABA levels in various parts of secondary dormant seeds(SDS)gradually declined during incubation but were still higher than in seeds for which dormancy was progressively released.GA 4+7 and GA 1+3 levels in embryos greatly decreased 35%and 24%,respectively,during incubation of SDS,and thus,the ratio of ABA to GA 4+7 in embryos and megagametophytes signifi cantly increased.The ratio of ABA to GA 1+3 in various parts of SDS increased slightly during incubation.In contrast,in seeds for which secondary dormancy was already released,GA 4+7 and GA 1+3 levels in the embryo,GA 4+7/ABA ratio in the embryo and seed coat,and the GA 1+3/ABA in the embryo and megagametophyte signifi cantly increased during incubation.There was no trend in the changes in the levels of ABA,GA 4+7 or GA 1+3 in embryos and megagametophytes of PDS or the levels of GA 4+7 or GA 1+3 in megagametophytes of SDS during incubation.The results suggest that high ABA levels in the seed coat maintain primary dormancy of Korean pine seeds.Maintenance of secondary dormancy involves a reduction of GA 4+7,GA 1+3,GA 4+7/ABA,and GA 1+3/ABA and the retention of high ABA levels.

关 键 词：Abscisic acid Gibberellic acid 4 and acid 7 Gibberellic acid 1 and acid 3 Korean pine Primary dormancy Secondary dormancy 

分 类 号：S791.247[农业科学—林木遗传育种]