绿潮漂浮浒苔繁殖特性的研究

我国黄海海域连续3年爆发大规模的绿潮，漂浮的绿藻在短短几个月之内生物量迅速增长，海域覆盖面积呈倍数扩增。选取漂浮绿藻中的优势种浒苔（Ulva prolifera）作为研究材料，对其繁殖特性进行研究。结果表明，每平方厘米藻体能够产生大约5.35×10⁶个游孢子或1.07×10⁷个配子；在繁殖高峰的5-8月间，一株成熟藻体25%左右的部分能够放散生殖细胞，产生约1.15×10⁷个游孢子或2.31×10⁷个配子。漂浮浒苔在此期间主要以单性生殖和无性生殖为主要繁殖方式，其中以单性生殖最为常见。其配子具有明显的正趋光性，合子具有负趋光性。漂浮浒苔的游孢子、配子或配子结合形成的合子均能发育成一株新的藻体。漂浮浒苔强大的繁殖能力是导致其生物量快速增长而引起绿潮爆发的主要原因之一。

Reproductive characteristics of the floating algae in green tide

In the last three years, vast green tides occurred repeatedly in the Yellow Sea area every summer. The biomass of floating green tide algae increased fast in a few months, moreover, the area covered by floating green tide algae expanded sharply. The material of this study is the dominant species Ulva prolifera in green tide. The reproductive characteristics study of the floating green algae showed that every square centimeter of the thalli produced about 5.35×10⁶ spores or 1.07×10⁷ gametes; during May to August, 25% surface area of the mature thalli produced about 1.15×10⁷ spores or 2.31×10⁷gametes. Parthenogenesis and asexual reproduction are the main reproductive modes of the floating green algae. Gametes showed intensive positive phototaxis, after syngamy, motile zygotes showed negative phototaxis. The spores and gametes could grow to new thalli independently, and the same to motile zygotes. As a result, the strong reproductive capacity of floating green tide algae Ulva prolifera might be the main reason of green tide occurrence.