Assessing the Germplasm of Laminaria （Phaeophyceae） with Random Amplified Polymorphic DNA （RAPD） Method

Eighteen gametophytes including L.japonica ,L.ochotensis and L.longissima,were verified with random amplified polymorphic DNA (RAPD) technique.Eighteen ten-base primers were chosen from 100 primers selected for final amplification test.Among the total of 205 bands amplified ,181(88.3%) were polymorphic ,The genetic distance among different strains ranged from 0.072 to 0.391,The dendrogram constructed by unweighted pair -group method with arithmetic(UPGMA) method showed that the female and male gamtophytes of the same cell lines could be grouped in pairs respectively,It indicated that RAPD analysis could be used not only to distin-gusih different strains of Laminariz ,but also to distinguish male and female gametophyte within the same cell lines,There is ambiguous systematic relationship if judged mereely by the present data It seems that the use of RAPD marker is limited to elucidstion of the phylogenetic relationship among the species of Laminaria.     

海带雌性原生质体的分离与培养

于1993年1月 - 1993年4月，为了制备遗传性纯一的基因工程受体，用酶法从海带雌配子体单性生殖系分离雌性单倍体原生质体。从皱纹盘鲍消化腺及消化器官提取出鲍酶，在25°C下、1％（W／V）的鲍酶与2％（W／V）的纤维素酶（Onozuka R－10）合用能有效解离单细胞和原生质体。海带雌性原生质体经2d培养再生了细胞壁。     

雌雄比对海带雌配子体发育的影响

本实验进行了不同雌雄比对海带雌配子体发育的影响。结果表明：雌雄比(鲜重)为1：1及2：1，实验组出现排卵时间最早，且发育率高，实验第20天，发育率超过70％，孢子体正常。5：1，10：1，20：1实验组随着雄性比例的减少，发育率逐渐降低，随着培养天数的增加，三个实验组均出现未受精卵及畸形孢子体，雌雄比越大，未受精卵数目越多。     

三疣梭子蟹雌雄隔离养殖技术研究

在193亩池塘中开展三疣梭子蟹雌雄分养和雌雄混养对比试验。其中雌雄分养面积93亩，亩产商品蟹182公斤，平均壳宽12．6厘米，平均个体重230．1克，成活率40．2％。与雌雄混养相比，亩产量提高了53．6％，成活率提高了1.51倍。专家鉴定认为，梭子蟹雌雄分养，方式新颖，效果明显，技术水平属国内先进。     

海带配子体无性繁殖(克隆)技术研究与应用进展

海带具有异型世代交替,其配子体在单独分离培养时可进行营养生长,形成无性繁殖系(克隆)。本文简要回顾了海带配子体克隆技术研究与应用的历程,综述海带配子体克隆在海带种质资源保存、海带生理和遗传学研究及海带育种和苗种繁育中的应用现状。     

武汉地区自然光照度及其在光敏核不育上的应用

通过对自然光３年的逐日观测表明，一定照度的光时受天气状况影响发生明显变化，晴天光时长、阴雨天光时短，低温伴随着短光时。武汉地区光照度（Ｅ）大于５０ｌｘ，光时大于１３ｈ ４５ｍｉｎ的持续时间是６月￣８月１日，该时段内基本可满足光敏核不育的光照条件。     

Intraspecific crossings ofUndaria pinnatifida (Harv.) Sur.—A possible time-saving way of strain selection

Unicellular gametophytes ofUndaria pinnatifida (Harv.) Sur. were isolated in Qingdao, P. R. China in April 1993 and in Tokushima, southern Japan in March 1995. Different intraspecific crossings by using unicellular male and female gametophytes were successfully undertaken in Sept. of 1995 in Qingdao. Sporophytes were transplanted to two different locations for open sea cultivation. One was at Zhanqiao (ZQ) Bay where the water current was slower than that of another location—Taipingjiao(TPJ). A total of 218 adult sporophytes were harvested on January 12 and 18 from TPJ and ZQ respectively. For eacn combination, 10 sporophytes were cultivated. Analysis of the morphological characteristics of adult sporophytes indicated that the longest length between two bases of the serration of pinnate blades (W2) is a morphological characteristic that can be transferred from the parent plant to the next generations regardless of environmental variations. There was evidence that W2 was apparently determined by sex-linked factors, i.e., by male parental gametophyte. Sporophytes from certain crossing combinations showed more vigorous growth than those from other crossing combinations. It is therefore possible to select gametophyte strains which can be used as parental gametophytes for the seedling production of sporophytes with more vigorous growth within shorter cultivation period. The morphology of hybrids from a Qingdao strain and a Tokushima cultivated strain resembled that of both parental plants in frond features (wrinkled or smooth) and W2. Sporophyll formation also varied with strains. The fact that adult sporophytes resulting from the same crossing combinations have identical morphological characteristics under the same environmental conditions indicates the possibility of a new way to select strains which are expected to be ideal for commerical production by purposely selecting, propagating, and seeding unicellular gametophytes for sporeling production through freeliving techniques of gametophytes. Project 39400102 supported by NSFC, also supported by National Climbing Plan B (PD-B642); and Bioengineering Center, SSTC.     

柱撑蛭石吸附去除废水中重金属离子的实验研究

分别利用有机柱化剂十二烷基磺酸钠(SDS)和无机柱化剂聚羟基铝(HA)对蛭石进行柱撑制得十二烷基磺酸钠柱撑蛭石(SDS-V erm icu lite)和聚羟基铝柱撑蛭石(HA-V erm icu lite),并通过XRD、红外光谱、ZETA电位等表征手段对柱撑蛭石进行表征,同时针对柱撑蛭石对Cu2 ,Cd2 ,C r3 3种重金属离子的吸附进行研究,结果表明:吸附去除率受反应时间、重金属离子的初始浓度、pH值等因素的影响,经柱撑后的蛭石对重金属离子吸附的吸附性能比蛭石原矿要强。柱撑蛭石吸附3种重金属离子的动力学吸附过程可用E lov icb方程和双常数方程进行较好的拟合。     

The Role of Residential Location in Conditioning the Effect of Metropolitan Economic Structure on Male Youth Employment

Youths have increasingly experienced labor market problems over the last several decades. One fruitful line of explanation focuses on structural changes in the demand for labor stemming from deindustrialization, changing skill requirements for employees, and increasing supply competition from women and recent immigrants. While these explanations merit attention, they have not adequately considered facts that condition their impact. This paper considers the argument that intra-metropolitan residential location conditions the effects of metropolitan labor market structure on black and white male youths' employment probabilities. Using a sample of individual-level data drawn from the 1990 census combined with metropolitan-level indicators of economic structure, it was found that some structural effects varied between central-city and suburban male youths. The conditioning role of residential location, and the subsequent nature of the structural effects, varied considerably between black and white male youths. Interpretations of the conditioning role of residential location include a variety of social and institutional effects on individual residents and the stigmatizing effects of some neighborhoods, especially on black male youths.     

Identification of a Putative Tetrasporophyte-Specific Gene in Gracilaria lemaneiformis(Gracilariales, Rhodophyte)

A putative tetrasporophyte-specific gene, designated as SSH466 (GenBank accession No. DQ019223), was one of the genes identified in this work using suppression subtractive hybridization (SSH) method in Gracilaria lemaneiformis. The full length of the gene was obtained using SMART RACE strategy. Sequence analysis revealed that the gene had 1 019 nucleotides, including an open reading frame of 498 nucleotides encoding 166 amino acid residues, 158 nucleotides of 5' untranslated region and 363 nucleo- tides of 3' non-coding region. Protein motif and secondary structure prediction showed that there existed a transmembrane domain with a unique β-sheet. Thus, SSH466 protein might be a cross-membrane protein. Sequence homology search in the public GenBank databases did not reveal any significant match with SSH466. Virtual Northern blot analysis confirmed that it was a tetrasporo- phyte-specific gene.