LIFE-HISTORY AND SYSTEMATIC POSITION OF AKKESIPHYCUS-LUBRICUS (PHAEOPHYCEAE)
LIFE-HISTORY AND SYSTEMATIC POSITION OF AKKESIPHYCUS-LUBRICUS (PHAEOPHYCEAE)
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DOI：
10.1111/j.1529-8817.1986.tb00025.x
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发表时间：
1986-09-01
影响因子：
2.9
通讯作者：
KAWAI, H
中科院分区：
文献类型：
--
作者：
KAWAI, H
本文研究了一种被归为Coilodesmaceae或Punctariaceae，Dictyosiphonales的真菌Akkesiphycus lubricus Yamada et Tanaka的培养生活史。在培养中，该物种在微观丝状配子体和宏观多列孢子体之间交替，这是Dictyosiphonales和Laminariales共同的模式。然而，它有一个独特的雌雄异株配子体。未观察到大配子和小配子之间的融合。大配子或合子萌发，大部分发育成孢子体，形成单室孢子囊，其余的再发育成退化的配子体丝状体。配子体在5.5 ℃时成熟。C短日照条件，对应北海道冬季。孢子体发育正常，仅在低温条件下成熟，与日照长短无关。在系统位置上，Akkesiphycus lubricus与海带目的关系比与网管目的关系更近，其特征是：无蛋白核，孢子体薄壁组织形成早，配子或合子直接发育成孢子体，不形成基系统，游动孢子萌发后几乎空无一物，细胞内含物迁移到芽管中，游动孢子的细胞壁和细胞壁均为空。大配子囊由可育枝母细胞直接转化而成，小配子囊成簇形成，与长形伪索虫的精子器极为相似。
The life history in culture of Akkesiphycus lubricus Yamada et Tanaka, an alga which has been placed in the Coilodesmaceae or the Punctariaceae, Dictyosiphonales, was studied. In culture the species alternates between a microscopic filamentous gametophyte and a macroscopic polystichous sporophyte, a pattern common to the Dictyosiphonales and Laminariales. However, it has a unique anisogamous dioecious gametophyte. Fusions between macro-gametes and micro-gametes were not observed. Macrogametes or zygotes germinated, mostly developing into sporophytes that formed unilocular sporangia and the rest developed into reduced gametophytic filaments again. The gametophyte matures in 5.degree. C short-day conditions, corresponding to winter in Hokkaido. The sporophyte develops normally and matures only in low-temperature conditions irrespective of daylength. In regard to its systematic position, Akkesiphycus lubricus is considered to have a closer relationship with the Laminariales than with the Dictyosiphonales in the following characters: lack of pyrenoids; early stages of parenchyma formation in the sporophyte; direct development of sporophytes from gametes or zygotes without forming a basal system; zoospore becomes almost empty after germination by the migration of cell contents into a germ tube; formation of macro-gametangia by direct conversions of mother cells of fertile branches; and micro-gametangia formed in clusters showing close resemblance to the antheridia of Pseudochorda nagaii (Tokida) Inagaka.