珍稀濒危植物三棱栎种子的储藏特性鉴定

Seed Storage Behavior of Formanodendron doichangensis(Fagaceae),a Rare and Endangered Plant

由于三棱栎种子存在较高败育率,导致无法准确检测种子初始萌发率,因此对三棱栎种子的储藏特性一直不清楚,无法对该珍稀濒危物种提供最佳长期保存方案。本研究通过种子重力分离技术和X光成像系统检测技术,对三棱栎(Formanodendron doichangensis)的成熟种子进行优化清理,成功排除了空瘪种子对萌发实验的影响,通过研究脱水、低温和超低温对三棱栎种子活力的影响,明确鉴定了三棱栎种子的储藏特性,为该珍稀濒危物种提出最佳长期储藏方案。结果表明,种子重力分离技术有效地将三棱栎种子的饱满率从处理前的47%,提高到处理后的86%。根据国际种子储藏特性鉴定方法,三棱栎种子的含水量降到5%以下,种子活力为95%,仍与对照(92%)一致。极低含水量(<5%)的种子,在低温(-20℃)和超低温(-196℃)保藏处理3个月后,其活力仍为90%和91%。以上数据表明,三棱栎的种子能够耐受极端脱水和低温保藏,属于正常型种子,可以运用常规的种子库保存技术和储藏条件(即脱水低温条件)长期保存,该方法是珍稀濒危植物三棱栎种质资源进行长期保藏的最佳方法。

The seed storage behavior of Formanodendron doichangensis （Fagaceae） was still unclear due to the effect of empty seeds to the germination experiment caused by high abortion. Therefore there was lack of a best storage method for conserve this rare and endangered plant. In the present paper, the Selecta Gravity Separator and the X-ray imagine systems were introduced to successfully enhance the portion of the full and healthy seeds from the high aborted seed lot, and exclude the effect of empty seeds to the germination experiment. Moreover, the desiccation tolerance and low temperature tolerance of F. doichangensis seeds were tested to identify the seed storage behavior and the best storage method for this endangered species was provided. The results showed that Selecta Gravity Separator could efficiently improved the percentage of full seeds in the seed lot from 47% （before clean） to 86% （after clean）. F. doichangensis seeds kept high viability at 95% total germination similar to that of control seeds （92%）, when experienced the extreme desiccation treatment （ moisture content below 5% ）. After the storage at low temperature （ -20℃ ） and liquid nitrogen （ -196℃ ） for three months with low moisture content （ 〈5% ）, the seed germination remained at 90% and 91% respectively. In conclusion, the mature F. doichangensis seeds were desiccation tolerant and low temperature tolerant, which exhibited orthodox seed storage behavior according to the internationalseed storage behavior classification, and could be kept in the seed bank storage facilities for long term conservation.