【摘要】 <正> 在海带人工养殖研究工作中,首先遇着的就是从“采孢子”(使孢子附着在一定的人工基质上)起到幼孢子体生长出来这期间内的一系列问题;从问题的实质看来,这就是等于农业上的从播种到萌发这一关键性阶段的问题。由于海带具有大型的孢子体和从孢子萌发所形成的微观的配子体两个独立阶段,这个问题的中心是配子体的生长和发育,但同时也必然联系到游孢子附着后所形成的胚孢子的萌发。因此,从1951年开始进行海带研究工作起,我们就开展了对这些问题的研究。更多还原

【Abstract】 Observations have been made on the liberation and attachment of the zoospores of the haidai (Laminaria japonica).It was shown that the zoospores were most active at 10-15℃ and mostly adhered to the substrata provided, becoming the rounded embryo-spores within 2 hours, whereas at 5℃ they swam for as much as 48 hours without effecting adherence to the substrate and at 20℃, they were active for only a few minutes, with very low adhering ability. It was also observed that germination of the embryo-spores to gametophytes was completed within 3 days at10°,15° and 20℃,whereas at 5℃ it took much longer time for the entire germination process.Studies have been made on the influence of the temperature factor on the growth and development of the haidai gametophytes. The following results have been obtained:1.At5°, 10°, 15°, and 20℃, the haidai gametophytes grew normally. Theoptimal temperature for growth was judged by the shortest time (in term of the numbers of days) required for the cells to reach a certain diameter (22.2u) in the case of the usually single-celled female gametophytes and to exceed a certain number (>10) in the case of the many-celled male gametophytes. This was found to be about 15℃, at which growth proceeded the fastest. At 5℃, growth proceeded most slowly; at 10℃ and 20℃ growth proceeded much faster and at about similar rate,slightly better at 20℃.2.At 5°, 10° and 15℃,the haidai gametophytes were able to develop normally. The optimal temperature for development was judged by the shortest time (in term of the number of the days) required for the appearance of very young sporaphytes, and was found to be at about 10℃. At the other two temperatures, development proceeded at about similar rate, slightly better at 5℃.3.At 18℃, the haidai gametophytes grew normally, sometimes developing to the sporophytic generation and sometimes not; it was assumed that the different results under the same temperature were caused by temperature error (±0.5℃) as allowed by the experiments. Hence it was suggested that 18° was the upper limit of the developmental temperature of the Laminaria above which the gametophytes were unable to develop to sporophytes.4.At 20℃, the haidai gametophytes grew well, somewhat better than at 10℃ and sometimes similarly well as the optimal growth temperature 15℃. However, none of the gametophytes were able to develope to sporophytes.It is apparent, therefore, that the optimal growth temperature (ca. 15℃) is several degrees higher than the optimal reproductive temperature (ca. 10℃) for the gametophytes of Laminaria japonica. An explanation for such a phenomenum was offered. The haidai now under cultivation in China originally came from Western Hokkaido and northern Honshu of Japan. At these places, the summer surface water temperature is rather high, reaching 22℃ or higher, whereas the winter surface water temperature, quite low, usually lower 5℃.In nature, it takes the Laminaria about two months (from early to late autumn) to complete the part of the life history from the formation of sporangial sori and the liberation of the zoospores to the formation of juvenile sporophytes. During this period, the surface water temperature drops from 21-22℃ to about10 or lower. Long time adaption to the temperature characteristics of the regions under discussion naturally results in different optimal temperatures for the vegetive growth and development stages, higher in the former and lower in the latter. This assumption is well supported by the current practice of haidai cultivation in China.更多还原