光因子对离心列海链藻生殖的影响

Effect of light factors on sexual reproduction of Thalassiosira eccentrica

从厦门沿岸分离的离心列海链藻培养体，在光条件下发生有性生殖。实验结果获得，在20℃温度下诱导该藻雌雄配子形成的最适光强度分别为113和36μEin／（m2·s），最适光照时间分别为8和10h。有性生殖只在37μm宽度以下的细胞中发生，且精囊和卵囊的宽度大小十分相似。雄配子发育较为缓慢，精母细胞第一次核减数分裂之后经历了一个四鞭毛期。以上结果表明，有性生殖发生与细胞大小密切相关。该藻无性系培养体的性别决定呈双重表现型。光照时间和光照强度可影响性化强度和性别分化。

The cultures of Thalassiosira eccentrica (Ehr. )Cleve were isolated from the Xiamen coast and induced to go through sexual reproduction under light conditions in 1993. The results showed 36 and 113μEin/(m3·s)light intensity,and 10 and 8h lighe daily to be optimal for the formations of male and female gametes at 20℃in T. eccentrica sexual reproduction only occurred in the cells of less than 37μm wide. Spermatogonangia were similar to oogonia in widths. The development of male gamete slowly advanced. A four-flagellar stage appeared after the first meiotic nuclear division of spermatocyte. Thus,it is concluded that the induction of sexual reproduction is related closely to the cell slze. Sex determination of the clonal cultures was diplophenotypic in T. eccentrica. Sexual reaction and sex differentiation were influenced by light length and light intensity.