菹草生产力的研究

本文报道了水温、光照度、水的pH值和植株密度对菹草生产力影响的实验结果,以及植株不同部位上的生产力和叶绿素含量的测定值.在光照度8000lx和水温20—28℃的条件下,经51次测定,菹草顶枝的毛产量(P_G)在0.80—1.06毫克氧·小时/0.5克鲜重植物范围,平均值为0.92毫克氧·小时/0.5克;净产量(PN)在0.44—0.79毫克氧·小时/0.5克范围,平均值为0.61毫克氧·小时/0.5克.1小时的平均净光合率为1.11%,1小时的平均呼吸率为0.53%.       

草鱼、白鲢和花鲢的耗氧率

1.草鱼、白鲢、花鲢的鱼苗和第2年鱼,以及草鱼的第3年鱼在夏季水温下的耗氧率,均经连续至少7小时以上的测定。 体重0.4-1.7克的鱼苗,在28.5-31.7℃的水温中,平均耗氧率篇0.325-0.632毫克/克/小时;体重38.9-172.3克的第2年鱼,在26.3-30.6℃的水温中,平均耗氧率为0.161-0.264毫克/克/小时;体重1103-1355克的第3年鱼(草鱼)在水温21-23.5℃时,平均耗氧率为0.139-0.151毫克/克/小时。 2.耗氧率随体重的增加而减低;同种之内,小鱼的耗氧率较大鱼为高。 3.耗氧率随水温的上升而增加;花鲢在冬季的耗氧率不及夏季的1/6。 4.在体重和水温相仿的情形下,白鲢的耗氧率较花鲢为高,花鲢的耗氧率又较草鱼为高。     

论鲢、鳙对微囊藻的消化利用

1980年—1985年7—8月在水温30℃,溶氧8mg/L以上,pH值7—8,光照度2800lx的限制摄食量条件下,鲢、鳙鱼种对微囊藻干物质的消化率分别为29.45±4.37、26.07±2.15％;蛋白质消化率分别为39.20±3.44、33.71±2.93％;脂肪消化率分别为34.03±5.38、30.29±2.16％;碳水化合物消化率分别为36.61±4.15、30.39±2.81％。鱼种对微囊藻日需量分别为其体重的54.44和60.53％。鱼的生长与其生活水体中藻类的初始浓度有密切关系:(1)藻类浓度在0.4—0.8g/L时鲢、鳙分别增重1.55—7.41和0.78～6.21％;(2)藻类浓度在1.0—1.3g/L时鲢、鳙分别减重2.0—5.9和2.2—8.3％。0.8g/L为鲢、鳙滤食微囊藻的最大浓度。     

盐碱池塘浮游植物初级生产力的研究

根据黑白瓶测氧法测定 ,山东省高青县赵店渔场盐碱池塘鱼类生长期内 (4— 9月 )浮游植物初级生产力为9 42± 4 2 1gO2 (m2 ·d) ,日P/B系数平均 0 2 4± 0 18,浮游植物对太阳有效辐射的利用率平均 1 5 3%。无鱼对照池浮游植物初级生产力显著低于养鱼池。回归分析表明 ,浮游植物现存量、透明度、水温、盐度是决定盐碱池塘浮游植物初级生产力的主要生态因子。营养盐中磷比氮的限制作用大。文中探讨了养鱼池初级生产力在能量转化中的生态学效率。     

中华绒螯蟹幼蟹标准代谢的研究

对中华绒螯蟹幼蟹的耗氧率、CO2 排出率及NH3-N排泄率进行了测定 ,并研究了幼蟹的能耗率及能源物质的供能比。结果表明 ,体重 ( 2 70± 1 4 0 )g的幼蟹 ,在水温 ( 2 0± 0 5 )℃时 ,耗氧率、CO2 排出率和NH3-N排泄率分别为 ( 0 4 14± 0 0 91)mg·g-1·h-1、( 0 4 76± 0 12 5 )mg·g-1·h-1和 ( 4 179± 1 171) μg·g-1·h-1;标准代谢的蛋白质、碳水化合物和脂肪提供的能量比为 7 3∶3 8 8∶5 3 9。其耗氧率 (R0 )受水中溶氧水平的影响 ,并与体重(W )呈负相关 (R0 =0 84 0 3W-0 72 6 5)。     

越冬池冰下浮游生物的研究

越冬池冰下浮游植物主要由光甲藻、隐藻、小环藻、壳虫藻、衣藻、棕鞭藻等优势属组成,重点试验池平均生物量为38.8±13.06毫克/升。与明水期相比其种数较少而现存量不低;原生动物、桡足类和轮虫类构成冰下主要浮游动物。重点池平均生物量为6.21±6.52毫克/升,其中轮虫量最高。冰下浮游植物量各水层不同,86.7％的越冬池表层多于底层,另13.3％底层多于表层。光甲藻等鞭毛藻有明显的昼夜垂直移动。冰下浮游生物量有月变化和年变化,文中分析了引起这些变化的生态因素,同时探讨了与生物增氧有关的几个问题。     

驳骨丹器官培养诱导植株

植物名称:驳骨丹Buddleia asiatica Lour. 材料类别:3～4年生苗木春梢的茎段。培养条件:外植体在MS+BA_2毫克/升+NAA0.2毫克/升培养基上诱发愈伤组织,愈伤组织转移到MS+BA1毫克/升培养基上诱导出芽,待芽伸长,再转入1/2MS+IBA0.5毫克/升诱导发根,25±2℃恒温,每天9～10小时光照,光强1500勒克斯。     

龙须菜(Gracilaria lemaneiformis)的生长、光合作用及其对扇贝排泄氮磷的吸收

研究了不同温度、光照条件下大型藻类龙须菜(Gracilaria lemaneiformis)的生长和光合作用特性,及其对扇贝排泄氮、磷的吸收作用。结果表明温度与龙须菜的生长和光合作用显著相关,在本实验条件下,15~25℃都适宜龙须菜生长,其中20℃龙须菜具有较高的生长率(SGR),为2·8%/d;光合作用速率随温度升高和光照的增加而升高,30℃和120μmol/(m2·s)时最高,最大光合作用速率(Pmax)为5·0mg O2/(g dw·h)。龙须菜对扇贝排泄氮、磷有较强的吸收作用,其吸收率和去除效率与放养密度和养殖时间有关。对NH4-N和PO4-P的最大去除效率分别为83·7%和70·4%,最大吸收率分别为9·9μmol/(g ww·h)和4·3μmol/(g ww·h)。实验证明龙须菜生长温度范围和光照范围适合中国北方海区养殖,并且能有效吸收和去除扇贝排泄氮、磷,可以作为生物滤器与贝类及其他养殖动物进行综合养殖。     

风信子的组培

用风信子(Hyacinthus orientalis) 的小鳞茎常规消毒,切成0.4×0.4厘米的小块,接种在MS+6BA10毫克/升+ NAA1毫克/升培养基内,在15—20℃自然光加1000勒克司日光灯,每天10小时光照15天后,形成愈伤组织块,一个月后每块形成10—66个胚状体。将胚状体移植于生长培养基MS+6BA2毫克/升+NAA2毫克/升内继续培养,15天后     

曼氏无针乌贼耗氧率及溶氧胁迫对其体内酶活力的影响

采用Winkler法测定水中溶氧含量,通过比较对照呼吸室与试验呼吸室水中溶解氧含量之差确定曼氏无针乌贼耗氧率及窒息点,并在不同程度的溶氧胁迫下测定乌贼体内多种酶的活力变化.结果表明：曼氏无针乌贼耗氧率呈明显的“高-低-高-低”昼夜变化;耗氧率与水温(16 ℃～28 ℃)和光照(3～500 μmol·m^-2·s^-1)呈正相关,与pH值(6.25～9.25)呈负相关;随着盐度的升高(18.1～29.8),乌贼耗氧率呈“高-低-高”变化,盐度为24.8时耗氧率最低;雌性乌贼耗氧率高于雄性.窒息点随乌贼的体质量增加而降低,平均体质量为(38.70±0.52) g的乌贼窒息点为(0.9427±0.0318) mg·L^-1.随着溶氧胁迫程度的增加,超氧化物歧化酶(superoxide dismutase, SOD)、过氧化氢酶(catalase, CAT)和过氧化物酶(peroxidase, POD)活力均先升后降,脂肪酶活力下降,蛋白酶活力呈“降-升-降”变化;乳酸脱氢酶(lactate dehydrogenase, LDH)活力呈先升后降趋势,但溶氧胁迫下的酶活力比正常时要高.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.