顽拗性竹柏种子的贮藏特性

文章对竹柏(Podocarpus nagi)种子的脱水耐性和贮藏特性进行了研究,结果表明:竹柏种子成熟时初始含水量约为(35±0.7)%,种子对脱水敏感,其最低安全含水量约为(16.86±0.73)%,具有顽拗性种子的典型特征;湿藏和半干藏都可以作为短期保存竹柏种子的方法,且以4℃保存优于15℃保存,但不管种子含水量如何,零下低温保存对竹柏种子都是致命的;半干藏法保存实验中,未进行脱水处理的种子(对照)在4℃贮藏6个月,种子萌发率没有发生明显下降,但贮藏期延长到9个月时,临界含水量的种子萌发力保存最高;不管贮藏介质的含水量高低,也无论贮藏在4℃还是15℃,湿藏种子在9个月的贮藏期内萌发率均没有明显的降低,但当贮藏到12个月时,15℃湿藏种子的萌发率显著高于4℃贮藏的种子,但15℃湿藏的种子在贮藏到3个月时即发现种子在贮藏期间萌发,且随着贮藏介质含水量的升高和贮藏期的延长,萌发的种子增多;竹柏的离体胚经过2 h硅胶快速脱水至含水量7%后再冷冻即可获得90%以上的融后存活率,且超低温保存1年的离体胚解冻后,与只保存1周的存活率没有明显差异,表明超低温长期保存竹柏种子是可行的。本研究可以为进一步探究顽拗性种子的短期贮藏和长期保存提供理论基础和基础资料。

Storage Behavior Characteristics of Recalcitrant Podocarpus nagi Seeds*

 This paper studied desiccation tolerance and optimal storage methods of Podocarpus nagi seeds and achieved the following results: Podocarpus nagi seeds were desiccation sensitive and recalcitrant, with an initial moisture content of (35 ± 07)% and a critical moisture content of (1686 ± 073)%; both moist storage and partially dried storage can be applied to short term conservation of Podocarpus nagi seeds in practice, and storage at 4℃ produced better results than that at 15℃, but storage at sub zero temperature was lethal no matter what seed moisture content was; In the partially dried seed storage experiment, the un dried seeds (the control) had no obvious viability decrease during 6 months’ storage duration at 4℃ but seeds at critical moisture content had higher viability than those at other moisture contents after 9 months storage; no matter what media moisture content was used, and whether stored at 4℃ or 15℃, 9 months’ moist storage did not reduce Podocarpus nagi seed viability while seeds stored at 15℃ had significantly higher viability than those at 4℃ when storage expanded to 12 months, but some of these seeds were found germinating during 15℃ storage at the third month, and more and more germinated seeds there were as media moisture content and storage duration increasing; 2h flash drying to moisture content 7% let more than 90% excised embryos survive freezing thaw treatment and one year’s cryo storage made no difference to their post thaw survival, indicating that it is feasible to cryopreserve Podocarpus nagi. These findings can be referred to short and long term conservation of recalcitrant seeds.