原植体

但原植体耐光性比藻丝体强，说明在野外胶鞘对保护发菜免受强辐射伤害有重要意义。

But photostability of thallus is better than that of filament , which means sheath can protect cells form radiation .

原植体为丝状或片状，大小不一，小的仅数个细胞，大的形态复杂如树状。

Composed of filaments or plates of cells , a thallus ranges in size from a single-celled structure to a complex treelike form .

染色效率与原植体类型和细胞密度有关。

The staining rate has relation with the cell density .

形成藻殖段是发菜原植体繁殖的主要方式。

Forming hormogonium is a main reproductive way of Nostoc flagelliforme by thallus .

水生原植体的光合固碳能力比天然原植体高。

The aquatic-living colonies had a higher photosynthetic carbon fixation capacity than the natural colonies .

在液体培养条件下，当没有任何干出（暴露于空气中让其干燥）处理时，原植体的鞘在2天左右即解体。

Under submerged aquatic conditions , the colonial filaments disintegrated with their sheaths ruptured in about 2 days without any desiccating treatments .

两种原植体都显示出对干旱胁迫的耐受性，在失水为80%的时候依然可以维持正的光合作用。

Both forms of colonies exhibited a higher tolerance to desiccation stress , even at the water loss of 80 % , they still maintained positive photosynthetic rates .

主要结果如下：发状念珠藻的水生原植体和天然原植体在沉水状态与干燥失水（干出）状态时，其光合作用的最适温度都是25℃。

The main results are as follows : Whether under submersed or emersed conditions , the optimal temperature for photosynthesis of both aquatic-living and natural colonies was 25 ℃ .

在细菌控制培养中，即使不作任何干出处理，原植体的鞘在短时间内也不会解体，其完整性可以维持20天左右。

When the bacteria in culture was controlled , the colonial filaments did not disintegrate in short time , and maintained the integrity of their sheath for about 20 days even without the desiccation treatments , indicating the importance of desiccation for N.

发状念珠藻（俗名发菜）是一种高经济价值的陆生蓝藻，但迄今尚未实现其人工栽培。近期成功地培养出的水生原植体具有应用前景，然而对其生物学特性尚缺乏认识。

Nostoc flagelliforme ( Berk Curtis ) Bornet Flash is a terrestrial cyanobacterium with high economic value , while its cultivation has not been successfully achieved . The recently developed aquatic-living colonies bear applied foreground , but little was known about their biological characteristics .