四川大头茶种子贮藏行为的分析  

Investigating Seed Storage Behavior of Gordonia acuminate(Theaceae)

作　　者：田美华[1] 唐安军[1] 

机构地区：[1]重庆师范大学生命科学学院,重庆401331

出　　处：《种子》2013年第9期27-32,共6页Seed

基　　金：国家自然科学基金(编号:31171588);重庆师范大学校级基金(编号:2011 XLS 34);重庆市教委科技基金(编号:KJ100610)

摘　　要：四川大头茶（Gordoniaacuminata）是中国西南地区常绿阔叶林优势种之一，可用作行道树或园林景观植物。迄今尚未见有关四川大头茶种子贮藏生理的研究报道。为促进该植物种子的离体保存，本研究系统分析了四川大头茶种子贮藏行为及其生态意义。通过测量得知，成熟的四川大头茶种子千粒重约18．3g，初始活力为94％；初始含水量为33．1％的种子在25、30℃和变温30／20qC（光周期为12h／d）的萌发率分别为91．7％、86．7％和90％。因此，四川大头茶种子是非休眠的。用硅胶脱水后，含水量≥10．3％的种子能较好地萌发（萌发率〉86％），但是，当含水量为8．1％时，种子萌发率降至53．3％。而且，在脱水过程中，超氧化岐化酶（SOD）活性逐渐下降；过氧化氢酶（CAT）活性在含水量10．3％时最强，进一步脱水，CAT活性显著下降；膜脂过氧化产物（MDA）的含量因种子失水而不断增加。此外，控制条件的贮藏试验表明，含水量≥10．3％的四川大头茶种子可以在O-10℃之间短期贮藏。结果表明：四川大头茶种子是中间性的。在功能生态进化层面，产生中间性种子是四川大头茶繁殖生态的适应性之一，是一种重要的进化策略。Gordonia acuminata is one of the species dominating evergreen broad-leaved forests in the southwest China, which is being used as roadside trees and ornamental plants in the garden and park. At present, little information on seed storage physiology is available. Thus, we investigate the storage behavior and its ecological implication of this species, aiming at ex-situ conservation by seed banks. The 1 000-seed weight of this species and the initial seed viability was 18.3 g and 94% ,respectively. Freshly harvested mature seeds with 33.1% water content germinated to 91.7%, 86.7% and 90% at 25 ℃ ,30 ℃ and 30/20 ℃ ,respectively,with a 12-h photoperiod. After drying with active silica gel,the seeds with I〉 10.3% of water content germinated to more than 86% ; however, the germination percentage of the seeds with 8. 1% water content was 53. 3%. In addition,when the seed water content was decreased from 33.1% to 10.3% ,and to 8.1% ,activities of SOD gradually decreased from 12.37 units/mg protein to 7.61 units/mg protein, and to 3. 12 units/mg protein; Also,activities of CAT continuously increased from 11. 52 units/mg protein to 21. 37 units/mg protein. Moreover, MDA of lipid peroxidation product gradually accumulated with desiccation. Especially, storage exper iments under controlled conditions confirmed that the seeds with I〉 10.3% could be conserved for a short period （i. e. ,6 months） between 0 ℃ and 10 ℃. Based on these results above, we concluded that G. acumina ta produces intermediate seeds. Certainly, the intermediate seed is a functional trait of plant regeneration ecolo gy, which is an important evolutionary strategy for this species adapting changing environments.

关 键 词：中间性种子 脱水敏感性 贮藏行为 功能特征 四川大头茶 

分 类 号：S792[农业科学—林木遗传育种]