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甜菜幼苗刚出土时,春霜能冻死幼苗。在严格控制的实验室和人工气候箱条件下,调查研究了可能解决这一问题的各种溶液。发芽实验是在不同温度条件下,在渗透压不同、已知能增强其他作物耐寒力的各种化合物的溶液中进行的。发芽后,用不同最低温度的冰块冰冻幼苗,记下受害程度。结果表明:幼苗存活涉及两种机制。一种机制与植株汁液的渗透势有关,另一种机制与汁液中水分含量有关,它可能变成冰而不会使幼苗致死。使幼苗的根接触溶液,能增加幼苗的渗透压,而发芽期低温则可增加其耐冰性。这两种因素呈很强的正相关,并能将正常致死温度从—0.5℃降到—2.5℃。一些生长调节剂和曾报导能增加其他作物耐寒力的另一些化合物则都无效。
Beet seedlings just unearthed, spring frost can freeze seedlings. Under well-controlled laboratory and artificial climate chambers, various solutions to this problem were investigated. Germination experiments are carried out in solutions of various compounds known to enhance the cold tolerance of other crops under different temperature conditions, at different osmotic pressures. After germination, freeze the seedlings with ice cubes of different minimum temperature and note the degree of victimization. The results showed that seedling survival involves two mechanisms. One mechanism is related to the osmotic potential of plant juices, and the other mechanism is related to the moisture content of the juice, which may turn into ice without lethal seedlings. The roots of seedlings in contact with the solution, can increase the osmotic pressure of seedlings, and germination of low temperature can increase its resistance to ice. These two factors are strongly positive and can reduce the normal lethal temperature from -0.5 ° C to -2.5 ° C. Some growth regulators and other compounds that have been reported to increase the cold tolerance of other crops are ineffective.