Cryopreservation and Evaluation of Chinese Arbor-Vitae (Biota Orientalis) Seeds

• Published in: Journal of new seeds Vol. 10; no. 4; pp. 264 - 276
• Main Authors: Shahab, M. Naderi, Hatami, F., Tabari, M., Jafari, A. A.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 24.11.2009
• Subjects: 30% glycerol; Biota orientalis; cryopreservation; desiccation; germplasm collection; long term seed storage; plant vitrification solution; PVS2
• ISSN: 1522-886X; 1522-9025
• DOI: 10.1080/15228860903303957

Under cryopreservation conditions or at −196°C, because of extreme reduction of metabolic and physiologic processes, the seed sample or plant organ can survive for a long time. Chinese arbor-vitae (Biota orientalis (L.) Endl.) is one of the endangered forest species in Iran. To preserve B. orientalis seeds under cryogenic conditions, three cryopreservation treatments, including plant vitrification solution 2 (PVS2), 30% glycerol, and seed desiccation, were applied before transferring the seeds into liquid nitrogen. In desiccation, the moisture content of seeds dropped from 8.95% to 5.56% in silica gel at +4°C. All of the treated seeds except control were transferred into liquid nitrogen (−196°C), and preserved for periods of one week, one month, and one year. After removal of the seeds from liquid nitrogen, they were exposed to a heat shock (+42°C), washed, and evaluated by standard germination tests. Furthermore, the second samples of the same seeds were sown in pots and grown in greenhouse (22 ± 4 °C temperature) for one year. Seed germination, root and shoot lengths, germination speed, root/shoot length ratio, and seed vigor index (VI) were recorded and statistically analyzed. Seed germination percentages in PVS2 treatment for one-week, one-month, and one-year storage in liquid nitrogen were 95.94, 94.55, and 94.36, respectively, which statistically were not significant. High level of recovery from liquid nitrogen (−196°C), seed germination, and other attributes, in either laboratory or greenhouse conditions, revealed the cryogenic (−196°C) tolerance of this endangered species. The one-year old plants originated from cryopreserved seeds and grown under greenhouse conditions grew normally and did not show any abnormality when compared with the control plants. Keeping B. orientalis seeds under cryopreservation conditions (liquid nitrogen) is a reliable and long-term method of preserving them. Moreover, with the use of this technology, the seeds of this endangered species can be collected from different habitats and preserved for a long period. To save a species from becoming extinct, the seeds can be recovered and replanted in the disintegrated habitats with the aim of afforestation.