鼠尾藻有性繁殖和幼孢子体发育的形态学观察

Morphological Observation of Sexual Reproduction and Juvenile Sporophyte Development in Sea Weed Sargassum thunbergii

野外跟踪观测烟台芦洋湾地区鼠尾藻的成熟繁殖状况,采集临近成熟的鼠尾藻至实验室培养,跟踪观测其卵子的排放、卵子和受精卵的发育、假根的生长以及幼孢子体的前期发育。试验结果表明,本地区鼠尾藻繁殖期集中在6—8月,鼠尾藻的卵子发育属8核1卵型,卵子受精后约20 h开始脱离生殖托,受精卵先连续进行2次的横分裂,而后再由一端的1个细胞发育成假根,另外2个发育成体细胞。幼孢子体在约2 mm时开始形成分枝突起。

Field observation of reproductive process in sea weed Sargassum thunbergii was carried out and semi - mature sea weed was collected before the reproduction and then cultivated in laboratory where the release of ova, development of the fertilized zygotes, growth of rhizoids and early development of juvenile sporophyte were primarily studied. It was found that the sea weed reproduced mainly from June to August, had the ovum of 8 - nuclei, and began the zygote disengaged from receptacle approximately 20 h after fertilization. After taking transverse division twice, one terminal cell developed into rhizoid and the two others developed into the juvenile sporphytes. The juveniles started growing new branch when they reached nearly 2 mm in length.