珍稀植物银杉的种子萌发特性  

Seed germination of endangered Cathaya argyrophylla Chun & Kuang

作　　者：曹基武[1] 刘春林[1] 张斌[1] 吴毅[1] 朱玲[1] 刘国[1] 李双春[1] 

机构地区：[1]中南林业科技大学,湖南长沙410004

出　　处：《生态学报》2010年第15期4027-4034,共8页Acta Ecologica Sinica

基　　金：国家林业公益性行业科研专项(200804001);国家948项目(2009-4-14);国家林业局项目(2007-353);湖南省科技厅项目(S2006N333);长沙市园林局重大项目(2008-01)

摘　　要：银杉(Cathaya argyrophylla)为我国特有珍稀古生树种,其种群自然更新困难,被列为国家Ⅰ级重点保护植物。由于银杉种子自然发芽率低,对其种子萌发过程的生理生态特性进行研究显得十分必要。对银杉种子的千粒重、含水率等物理特性及不同保存方法对种子生理活性影响进行了研究,重点研究了银杉种子经激素处理后其发芽率的变化趋势以及不同贮藏方法对种子萌发率以及抗氧化酶系统活性的影响。结果表明:储存时的水分条件是保证生活力的关键,失水带来的逆境胁迫导致银杉种子抗氧化酶活性变化剧烈,长时间的胁迫(报纸储存90d)造成种子能量消耗严重,抗氧化酶活性下降剧烈,导致发芽率极低(2.50%);用苔藓包裹低温贮藏的方法对种子活力影响最小,种子的发芽率最高,且能较长时间的保存。用不同激素处理后,能对种子的发芽有一定的促进作用,其中以IAA表现最好,特别是100mg/L浓度的IAA能提高种子发芽率30.30%,效果明显,但随着贮藏时间的延长,由于银杉种子自身活力丧失迅速,激素浸泡处理效果并不显著。Cathaya argyrophylla Chun Kuang,a monotypic genus of the pine family,is endemic to China.Chinese government lists it as a Class-I protected plant because of its limited individuals in the wild.Natural regeneration is rare and it is imperative to better understand its eco-physiological characteristics of seed germination.Cones of Cathaya argyrophlla were collected from selected healthy and 60-100 years old individuals and there are 490 to 520 cones per kilogram.Every 100 cones produced 4.36 seeds and every 1 000 seeds weight 15.8 grams.TTC test concluded that the seed viability is 50.50%.Storage method and duration significantly affected seed germination.The highest germination rate,33.00%,was produced under moisture moss at 4 ℃ after storing for 30 days.Both moisture newspaper and sand did not greatly reduce germination rate at 30 days.However,average seed germination was significantly lower from 31.0% to 18.0% to 7.0% as the storage durations went from 30 to 60 to 90 days.After storing for 90 days,seed germination were 13.0% and 2.7% for storing in moisture moss and newspaper,respectively.For the long-term storage,moisture moss is recommended.Seed POD,SOD activities and MAD levels during storages changed dramatically.The highest POD and SOD activities,5.58 mmol/g and 300 U/（g min）,occurred under moisture newspaper at 30 days,which significantly higher than other two storage methods.As storage days went up,no significantly difference occurred among three storage methods.The average POD and SOD were 0.48 and 100 at 60 days,0.71 and 96.8 at 90 days.MAD content kept high at 2.71 mmol/g under the moisture newspaper stored for 30 days,then from 0.08 to 0.51 for other storage methods and duration.After storing for 60 and 90 days,POD,SOD activities and MAD level were relatively lower and no significant difference was found among the storage methods.Hormones GA,NAA,and IAA could significantly influenced germination rates.Under the moisture newspaper storage,seeds soaked for 24 hours in 100 mg/L of NAA and IAA after

关 键 词：银杉 种子萌发 生理活性 酶活性 激素处理 

分 类 号：Q945[生物学—植物学]