pH对红鳍东方纯（Takifugu rubripes）消化酶活力的影响

本文研究了pH对红鳍东方纯消化道和肝胰脏中蛋白酶、淀粉酶和脂肪酶活力的影响。结果表明：红鳍东方纯前肠蛋白酶和淀粉酶最适pH分别为：5．4和5．0;中肠蛋白酶和淀粉酶的最适pH分别为：8．7和7．0;后肠蛋白酶和淀粉酶的最适pH分别为：6．5和7．0;肝胰脏蛋白酶和淀粉酶的最适pH均为7．0;肠和肝胰脏的脂肪酶的最适pH均为7．0。     

Using Bacillus subtilis E20‐fermented soybean meal as replacement for fish meal in the diet of orange‐spotted grouper (Epinephelus coioides,Hamilton)

The potential of Bacillus subtilis E20‐fermented soybean meal (FSBM) as a partial alternative component of fish meal (FM) in fed diets of orange‐spotted grouper (Epinephelus coioides) was evaluated in this study. An FM‐based diet and seven diets containing 10%, 20% and 30% and 10%, 20%, 30% and 40% of FM replaced by soybean meal (SBM) and FSBM, respectively, were fed to grouper for 84 days to evaluate possible substitution levels of FM by tracking growth performance, digestive enzyme activity and morphological changes in the liver and distal intestine. No significant differences in survival and muscle composition of grouper were found between controls and treatments. Growth performance and feed efficiency of fish fed diets with FM replaced by FSBM up to 30% were not significantly different from controls, whereas significantly decreased growth performance and feed efficiency occurred with diets containing >20% of SBM. Based on the feed efficiency, the maximum substituted levels of FM by SBM and FSBM in grouper diets were 18.36% and 29.32%, respectively, based on broken‐line analyses. Histopathological changes in the liver and distal intestine, and significantly lower activity levels of digestive enzymes, including pepsin in the stomach and trypsin, chymotrypsin, amylase and lipase in the distal intestine, were found in fish fed a diet containing 30% of FM replaced by SBM. However, these parameters were improved by the substitution of FSBM. It is therefore believed that FSBM has great potential to be used as a protein source in grouper diets in partial replacement of FM.     

多种接种途径对翘嘴鳜细菌性烂鳃和败血症的免疫预防效果

多种接种途径对翘嘴鳜细菌性烂鳃和败血症的免疫预防效果陈昌福，周文豪（华中农业大学水产学院，武汉４３００７０）陈昌福等（１９９５）先后用从患细菌性烂鳃病的翘嘴鳜（ＳｉｎｉｐｅｒｃａｃｈｕａｔｓｉＢ．）上分离的柱状嗜纤维菌（Ｃｙｔｏｐｈａｇａｃｏｌｕｍｎ...     

两种盐度下凡纳滨对虾饲料中的最适动植物蛋白比

试验研究了不同盐度下（3和22）,以鱼粉和大豆浓缩蛋白为蛋白源,配制6种不同动植物蛋白比的饲料对凡纳滨对虾生长、成活和肝胰腺可溶性蛋白质含量的影响,饲养试验为期40 d。结果显示：（1）饲料动植物蛋白比可显著影响凡纳滨对虾增重率、成活率、肝体指数、肥满度和肝胰腺中可溶性蛋白质含量。增重率随饲料动植物蛋白比升高而升高,但当饲料中动植物蛋白比升至29∶8时,增重率不再明显升高,其它指标均先随饲料动植物蛋白比升高至一定程度,而后则稍有下降;（2）盐度22组对虾的增重率、成活率和肥满度显著高于盐度3组对虾,肝体指数却显著低于盐度3组,不同的盐度对凡纳滨对虾肝胰腺可溶性蛋白含量的影响不显著;（3）双因素方差分析结果显示,盐度和饲料动植物蛋白比对凡纳滨对虾增重率、成活率和肝体指数存在显著交互作用,最大值分别出现在盐度22下全动物蛋白饲料组、盐度22下全动物蛋白和动植物蛋白为29∶8的饲料组、盐度3下饲料动植物蛋白比为14∶23的饲料组中;（4）Broken-Line分析表明,3‰盐度下凡纳滨对虾最适饲料蛋白比为29.12∶7.79~30.29∶6.71,盐度22时为26.05∶10.95~29.03∶7.44。结果提示,饲料中氨基酸的组成和含量会随配方中动植物蛋白配比而改变,且不同盐度下凡纳滨对虾对饲料中动植物蛋白比的要求有所不同,但配饵中适当的动植物蛋白比可以满足虾对各种氨基酸的适宜需求。因此,在养殖过程中,需结合实际的养殖环境和饲料蛋白源种类,来设计适宜的实用饲料配方,这样才能达到降低生产成本,提高经济效益的目的。     

江苏及安徽地区十个中华绒螯蟹成蟹群体的RAPD分析

采用随机扩增多态DNA(RAPD)技术对取自江苏及安徽地区的10个群体的中华绒螯蟹共64个个体进行了遗传多样性分析.从24个随机引物中筛选出15个扩增重复性好、条带清晰、特异性强的引物,共检测出88个位点(100～2000 bp),各群体的多态位点比例为3.45%～26.19%,遗传多态度为0.0141～0.1036,说明该蟹类基因组DNA多态度较为贫乏,遗传变异水平较低;各群体间的遗传距离为0.0237～0.2466,遗传相似度为0.7815～0.9766,该蟹类群体之间发生了一定程度的分化;分化系数为0.4283～0.6632,Nm为0.2539～0.6674,表明该蟹类群体之间发生了不同程度的遗传变异和遗传交换.     

湿地松幼苗根系微生物数量变化规律的研究

采用平板稀释法研究了湿地松幼苗1 a中微生物根系数量的变化规律,为合理的生物防治时期提供科学依据。结果表明:湿地松苗圃土壤中存在着大量的微生物。湿地松幼苗根系的生长和发展可以大大促进其周围微生物的生长,受湿地松根系生长和环境变化等因素的影响,在松苗移栽后的几个月内,根际细菌和真菌的种群数量迅速增加,细菌比真菌的种群增长速度要快。利用生物防治细菌进行苗木猝倒病防治的最佳时期应该是在芽苗移栽后1个月以内。     

中国古代木槿栽培应用发展史初探

木槿是中国传统的乡土花木,是栽培历史最悠久的花木之一。本文根据历史文献和诗歌等梳理分析了历史各个时期的木槿主要栽培应用史实和重要成果,分析了不同历史时期木槿的栽培应用、食用、药用与品种等发展演化情况,发现了诸多的习俗和应用被保留和传承,以期为木槿资源、文化及其产业的传承与发展提供思路。     

基于MCR模型的江西省抚州市生态安全格局构建

[目的]开展城市生态安全格局构建和主要生态廊道识别研究,为城市国土空间规划中生态格局的优化提供科学参考。[方法]以江西省抚州市为研究区,选取土地利用因子,水土保持功能重要性以及生态敏感性等多种因子构建最小累积阻力模型,依据生物多样性维护功能重要性评价、全域水文分析、生态保护红线以及自然保护地识别生态源地,依托MCR模型和ArcGIS中的空间分析工具开展研究。[结果](1)抚州市整体生态环境良好,水土保持功能极重要性区所占比例为49.97%,主要集中在抚州市中部地区,以黎川县、乐安县、宜黄县和南丰县为主;抚州市生态敏感性极重要区所占比例为1.39%;(2)生态源地面积3302.34 km~2,所占比例为17.57%,以抚州市东部和西南部为主;(3)以全域的生态要素和地形地貌等为基底,抚州市呈现出“一轴、两屏、多廊、多节点”的生态安全格局。[结论]结合生态源地、生态廊道和生态节点,形成完整、系统的生态保护格局和开敞空间网络体系,维护抚州市生态安全和生物多样性。     

Effects of long-term treatments of different organic fertilizers complemented with chemical N fertilizer on the chemical and biological properties of soils

Continuous cultivation has been known to decrease soil organic matter content. Application of organic matter to cultivated soil is an important practice from the point of view of maintaining an adequate amount of soil organic matter. Soil organic matter content significantly affects soil microbial activity, which is an important index of soil quality. In this study, a field experiment was conducted to examine the long-term effects of different kinds of organic matter in combination with inorganic nitrogen (N) fertilizer on chemical and biological properties of soils. There were seven treatments, namely (1) CK (without fertilization), (2) Chem-N (applying chemical N fertilizer only), (3) Comp (applying compost with the same rate of N as the Chem-N treatment), (4) Comp + l/3 N (applying compost complemented with 33% of the chemical N fertilizer of the Chem-N treatment), (5) Comp + 2/3 N (applying compost complemented with 66% of the chemical N fertilizer of the Chem-N treatment), (6) GM + 1/3 N (applying green manure complemented with 33% of the chemical N fertilizer of the Chem-N treatment) and (7) Peat + 1/3 N (applying peat complemented with 33% of the chemical N fertilizer of the Chem-N treatment). After continuous treatment for 12 years and with cultivation of 24 crops on the same area, soils were sampled for analyses of chemical and biological properties, enzymatic activities and phospholipid fatty acid (PLFA) profiles. The results showed that compared with CK and Chem-N treatments, applications of compost and peat increased soil organic carbon (SOC) content and altered microbial activities and microbial community structure. However, application of green manure for 12 years had no effect on SOC content. Both microbial activities and PLFA profiles were clearly dependent on the characteristics of the applied organic amendments. In summary, a peat application led to the highest increase in SOC content compared to compost and green manure; however, compost-treated soil had a higher microbial population and higher microbial and enzyme activities, while the effects of both green manure and chemical N fertilizer on soil properties were similar.