Ultra-dry preservation of tobacco seeds and its correlative technology

The objective of the research project is to concentrate on how to prolong the lifetime of tobacco seeds as long as possible, especially to preserve tobacco germplasm resources safely, and yet to prevent them from vanishing away. From 1994 on, a series of ultra-dry preservation and its correlative technology have been preliminarily identified. First, the moisture content of tobacco seed dropped below 5%, at an ultra-dried level, with different desiccants and different proportions between desiccants and seeds as well as different kinds of tobacco seeds, the disciplinarian of moisture content dropping, the disciplinarian of seed vigor change in ultra-dry process have been proved preliminarily in different treatments, and the optimal moisture content for tobacco seed within 1.5%～2.5% was also inferred. At the same time, the fact that a large number of tobacco seeds are suitable for ultra-dry preservation has been verified. Second, the average lifetime of tobacco seeds collected from 1979 to 1995 was predicted more than 25 years using three kinds of methods according to the average of the seed vitality dropping per year. Third, keeping a good preservation of ultra-dried tobacco seed, 4℃ is the best choice, and -8℃ is better, and it can also be stored in its original drier, but should avoid being preserved in natural or high temperature environment. The genetic variability for the most of seeds collected from 1979 to 2000 has not been observed in the period of seedbed or field. With the help of the series of technologies, more than 1500 tobacco germplasm resources have been stored successfully, thus the new technology for prolonging tobacco seed lifetime as well as for long-term, safe and effective preservation has been further probed.