杜氏藻同步化生长及核型分析

The Synchronous Growth of Dunaliella and its Karyotype Study

经１２ｈ光照和１２ｈ黑暗的光周期诱导，杜氏藻（Ｄｕｎａｌｉｅｌａ）出现同步化生长．以０．０５％秋水仙素处理、低渗及高位（６０ｃｍ）滴片，获得４种杜氏藻的核型．它们都是单倍体．染色体大多呈圆点状，极小．最长的染色体约为１．６μｍ，最短的染色体仅约０．５μｍ．染色体数分别是：Ｄ．ｐａｒｖａ１６条，Ｄ．ｂｉｏｃｕｌａｔａ２２条，Ｄ．ｐｅｉｒｃｅｉ２６条和Ｄ．ｍｉｎｕｔａ２８条．只有Ｄ．

Dunaliella, green algae adapted to salt, can be induced to divide synchronously when subjected to a 12 h light 12 h dark cycle at 25 ℃. Karyotypes of four species of Dunaliella have been found after a series of disposal of exposing them to colchicine (0.05 %) for 12 h, hypoosmotic shock and dropping from a high position(60 cm). They are all haploid. Most of the chromosomes are extremely little with round shape. The longest and shortest chromosomes are about 1.6 μm and 0.5 μm, respectively. Chromosome counts could be made as follows: D.parva, 16; D.bioculata, 22; D.peircei, 26; and D.minuta, 28. Primary constrictions can only be seen at 1st to fourth and seventh chromosomes of D.peircei.