我国榉属植物的生物学特性

比较研究了分布于我国的3个榉属种：大叶榉、光叶榉和大果榉（小叶榉）的生物学特性，发现它们虽然在许多性状上都表现出了较大的相似性，但是在形态特征和生物学特性等方面存在较大的差异。主要表现在树干颜色、叶质、冬芽的形状以及果实的形态和大小等方面。     

大叶榉播种育苗试验初报

经4a的大叶榉播种育苗试验，大叶榉种子于10月中下旬成熟，并有明显的大小年，大年种子出苗率高于小年种子。播种量75－150kg/hm^2。通过幼苗移栽、施肥、灌水、松土、除草、病虫害防治和及时修剪，1年生苗高可达到60－80cm，地径1.1cm，3年生苗高2.92m，胸径2.3cm。     

大叶榉组培苗生根诱导和移栽试验

为了解决大叶榉组织培养中生根难的问题,利用培养中得到的生长旺盛、茎长在2~4 cm的小植株作为试验材料,配合不同质量浓度的激素配比进行诱导生根和移栽试验。试验结果表明:大叶榉的最佳生根培养基为WPM ABT 2.0 mg/L,生根率可达97.3%,且生根的质量较好。炼苗阶段以黄心土和腐殖质土(质量比2∶1)为基质进行移栽,成活率高达100%。     

锯缘青蟹工厂化规模育苗技术的研究

1998年投入育苗用抱卵蟹44只,孵化蚤状幼体(Z_1)6250万只,育成大眼幼体409.76万只,平均成活率达到6.56％,平均单位水体出苗量达到6180只。稚蟹培育,投入大眼幼体409.76万只,培育出稚蟹(C_2～C_6)244.46万只,平均规格为个体甲壳宽1.17cm、体重0.22g,平均成活率达到56.60％,单位面积出苗量为441.26只/m~2,取得较好的经济效益。     

宝天曼地区枹栎群落学特征研究

以分布在河南宝天曼地区的Ｂａｏ栎群落为对象,分析了群落的特征和性质。对不同海拔的１５块样地材料的分析结果表明：Ｂａｏ栎群落中,Ｂａｏ栎的优势突出,呈单优势群落。Ｂａｏ栎群落土壤肥力较高,区系组成丰富,群落垂直结构较复杂,可会为乔木层、灌木层、草本层、亦有数量较多的层间植物;植物物种多样性指数较高。     

两种青蟹幼蟹水泥池套放网箱中间培育的比较研究

在水温25～27℃、盐度13～16、pH值7.5～8.5、连续充气的条件下,以PVC管和筛绢网制成的网箱进行拟穴青蟹(Ⅰ组)和锯缘青蟹(Ⅱ组)两种蟹苗的中间培育。结果表明:网箱培育的拟穴青蟹与锯缘青蟹的蜕壳率分别为47.28%和42.72%,彼此差异显著(p0.05);死亡率分别为32.88%和42.19%,彼此差异显著(p0.05)。Ⅰ组、Ⅱ组的增肉系数分别为21.10,14.17;甲长增长率分别为337.25%,304.99%;甲宽增长率分别为275.00%,204.42%。Ⅰ组、Ⅱ组的甲长与甲宽的关系分别为yⅠ=1.6455xⅠ-1.8486,yⅡ=1.7406xⅡ-2.7513;甲宽与体质量的关系分别为wⅠ=0.0264eⅠ0.2818x,wⅡ=0.0308e0Ⅱ.2772x;在本实验条件下青蟹密度为417只/m2时的存活率最高。表明水泥池套养网箱的中间培育模式是可行的。     

温度变化对锯缘青蟹免疫因子的胁迫影响

试验结果表明,温度变化对养殖锯缘青蟹免疫能力的影响显著。20℃时血细胞密度最高,远离20℃后,其血细胞密度随温度的上升或下降而逐渐降低,在10℃和30℃时降至最低;血细胞吞噬百分比在不同试验温度下无显著差异,但血细胞吞噬指数在25~27℃时极显著高于其他温度。血清溶菌酶和碱性磷酸酶活性皆在25℃时最高,并随温度的升高或降低而下降;酸性磷酸酶活力在20℃时最高,并随温度的升高或降低而下降;超氧化物歧化酶在不同试验温度下无显著差异;过氧化物酶在30℃时活性最低,其他各试验组间没有显著差异;酚氧化酶活性在30℃和27℃最高,其他各试验组间没有显著差异。试验结果表明,水温为20~25℃,锯缘青蟹相关免疫因子的各项指标较好,反映此时锯缘青蟹的抗病能力较强,而偏离该温度区间明显影响锯缘青蟹的免疫水平。     

孵化水体pH值对锯缘青蟹胚胎发育的影响

采用组织学、光学显微镜和卵离体培育法,探讨孵化用水pH对锯缘青蟹(Scyllaserrata)胚胎发育影响。研究结果表明:锯缘青蟹胚胎发育孵化水体适宜pH值7.0~9.0,最适pH值为7.8~8.2;pH值对锯缘青蟹孵化率、畸形率和成活率的影响相对显著,但对孵化时间影响不显著;pH值范围在7.0~7.8和8.2~9.0对锯缘青蟹孵胚胎发育影响大于7.8~8.2。     

Dietary protein requirement of giant mud crab Scylla serrata juveniles fed iso-energetic formulated diets having graded protein levels

The protein requirement of juvenile mud crab Scylla serrata (body weight=0.25±0.051 g, carapace width=9.3±0.04 mm) fed with different iso-energetic, iso-lipidic diets with graded protein levels (15–55% crude protein at 5% intervals) was determined. The feeding trial was conducted for a period of 63 days to determine the minimum and optimum protein requirement of juvenile S. serrata . The crabs fed with 15% and 20% dietary protein levels showed 100% and 12.5% of mortalities respectively. The mortalities observed in the above treatments were associated with the prolonged intermoult duration (46 and 32 days respectively). All other treatments recorded 100% survival. The best growth performance as well as the nutrient turn-over was recorded in crabs fed with 45% crude protein in the diet. Second-order polynomial regression of specific growth rate (SGR) as well as body protein gain vs. dietary protein levels suggested that 46.9–47.03% dietary protein is required for the best growth response and protein deposition in juvenile S. serrata . An extrapolation of 'SGR' and 'daily protein gain' upon the 'dietary protein level' axis ( Y =0) showed that 14.7–16.2% dietary protein is necessary for the minimum maintenance metabolism.     

Efficacy of various lipid supplements in formulated pellet diets for juvenile Scylla serrata

Efficacy of sunflower oil (diet SF) and soybean oil (diet SB) alone and in combination with cod liver oil (diets M1‐2.80:1.40:1.40, M2‐2.80:2.24:0.56 and M3‐2.80:0.56:2.24; cod liver oil:sunflower oil:soybean oil) as lipid supplements (5.6%) in formulated diets (crude fat ～9.79%) for juvenile Scylla serrata (weight=0.28±0.07 g, carapace width=9.7±0.1 mm) were compared with diet CL, containing cod liver oil alone as the lipid supplement (6 diets × 24 crabs stocked individually, randomized block design). Growth performance, nutrient (protein and lipid) intake and gain of crabs fed M1, M2 and M3 were higher (P≤0.05) than the crabs fed SF and SB, but were not significantly different (P≥0.05) from crabs fed CL. Dietary fatty acids (FAs) are found to influence the FA profile of test crabs. Higher tissue levels of 16:1n‐7, 18:1n‐9 and 18:1n‐7 reflected the essential FA deficiency in crabs fed diets supplemented only with vegetable oils. Results confirmed that S. serrata could utilize vegetable oil supplements in the formulated diets as a partial replacement (50%) of cod liver oil without compromising growth and survival. Partial substitution of marine fish oil with suitable vegetable oils can reduce the feed cost considerably, in the context of rising fish oil prices.