国家库贮藏20年以上种子生活力与田间出苗率监测

对34种作物1.4万多份的国家库贮存种子进行了生活力监测，结果表明，贮存20年后，92.9%被监测种子的发芽率仍保持在85%以上，但有155份种子（占被监测份数的1.1%）出现了明显的下降（发芽率从80%以上降至70%以下）。发芽率显著下降的作物包括蚕豆、红小豆、黄麻、蓖麻、甜菜、西瓜、烟草、牧草。小麦等8种作物2078份种子的田间出苗率调查表明，所有种质均有出苗，但有8份种质的出苗率低于10%。出苗率与入库初始平均发芽率存在差别，平均出苗率最高的作物为普通菜豆86.2%，比该批入库初始发芽率平均值低9.3%；平均出苗率最低作物为谷子39.2%，比该批种子的入库初始发芽率平均值低51.3%。总体而言，国家库内保存的作物种子中，多数可安全保存20年以上，尤其是水稻等禾谷类作物种子，但对于蚕豆、红小豆等平均监测发芽率出现显著下降的作物种子需要增加监测频率，以确保种子的长期安全保存。

Germinability and Seedling Emergence of Seeds after 20 Years of Storage in the National Genebank of China

In the present study, the viability of 14 thousands seed accessions, belonging to 34 crops, were detected after being stored at the National Genebank of China for 20 to 23 years. Results showed that the viability of 92.9% of the accessions were higher than 85%. Significant viability decline was detected in 155 accessions from broad bean, red adzuki bean, jute, castor, sugar beet, watermelon, tobacco and forage. A total of 2078 seed accessions from 8 crops, including wheat, soybean, sorghum, millet, cotton, peanut, common bean and watermelon, were uesd for seedling emergence survey. The results showed that each surveyed accession succeeded in seedling emergence, but the emergence percentage of 8 accessions was lower than 10%. The seedling emergence percentage was lower than the mean initial germination percentage. Among the 8 crops, the seedling emergence percentage of common bean was the highest, with a mean value of 86.2% of 126 accessions, which was only 9.3% lower than the initial germination percentage. The lowest seedling emergence percentage was found in millet seeds, with a mean value of only 39.2%, which was 51.3% lower than the initial germination percentage. To sum up, most of the collections in the National Genenbank of China can be safely conserved for more than 20 years, especially the cereal seeds, but as for the seed accessions that had showed significant reduction in the mean monitored germination percentage, for example, broad bean, red adzuki bean, etc, the viability should be monitored more frequently in order to assure the long-term safe conservation of these germplasm.