人工饲养倒刺鲃幼鱼的野化训练

为了探讨追赶训练对鱼类野化能力的影响,以倒刺鲃(Spinibarbus denticulatus)幼鱼为试验对象,采用鳜鱼塑料模型进行每天2次、每次5 min的追赶训练,研究了追赶训练7和15 d对倒刺鲃躲避模拟捕食者的逃逸时间、临界游泳速度(Ucrit)、摄食比率、特定生长率等指标的影响。结果显示,追赶训练7和15 d后倒刺鲃躲避模拟捕食者的逃逸时间显著低于对照组(P<0.05),摄食比率显著高于对照组(P<0.05)。追赶训练7 d后的Ucrit与对照组无显著性差异(P>0.05),但追赶训练15 d后的Ucrit显著高于对照组(P<0.05),而追赶训练15 d后的特定生长率相较对照组无显著性差异(P>0.05)。研究表明,采用该方法训练15 d后能提高倒刺鲃幼鱼的反捕食能力和游泳能力等与野外生存相关的行为能力,同时并不降低幼鱼的生长。追赶训练15 d的野化效果优于7 d。     

Dopamine modulates the physiological response of the tiger shrimp Penaeus monodon

Levels of glucose, lactate, pO₂, pCO₂, HCO₃⁻, TCO₂, Na⁺, K⁺, Cl⁻, protein, and oxyhemocyanin in the hemolymph and its osmolality and pH were measured when tiger shrimp, Penaeus monodon (13.5 ± 1.5 g body weight), were individually injected with saline or dopamine at 10^− 8, 10^− 7, or 10^− 6 mol shrimp^− 1. Results showed that hemolymph glucose, lactate, pCO₂, HCO₃⁻, and TCO₂ values increased from 2 to 4 h; hemolymph osmolality, Na⁺, and total protein had increased at 2 h; and hemolymph K⁺ decreased from 2 to 8 h after the dopamine injection. All physiological parameters returned to the control values 4–16 h after receiving dopamine. The dopamine injection also significantly decreased the oxyhemocyanin/protein ratio of P. monodon which occurred at 2 h, resulting from an elevation of hemolymph protein and a slight decrease of oxyhemocyanin. These results suggest that stress-inducing dopamine caused a transient period of modulation of energy metabolism, osmoregulation, respiration, and the acid–base balance in P. monodon in adapting to this environmental stress.     

不同水流速度对中华倒刺鲃幼鱼自由基代谢的影响

在(25±0.5) ℃下, 设置4个水流速度实验组, 分别为静水对照组0 bl/s(体长/秒)、1.0 bl/s组、2.0 bl/s组和4.0 bl/s组, 研究不同水流速度对中华倒刺鲃(Spinibarbus sinensis)幼鱼肌肉自由基代谢的影响, 训练周期为8周。结果显示, 肌肉超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-P_X)的活性随着水流速度的增加而升高, 训练组过氧化氢酶(CAT)活性出现不同程度的下降, 而抗氧化物谷胱甘肽(GSH)的含量未发生明显变化(P>0.05); 训练组肌肉总抗氧化能力(T-AOC)均高于对照组, 2.0 bl/s组最高, 4.0 bl/s组次之, 1.0 bl/s组最低, 且2.0 bl/s和4.0 bl/s组T-AOC与对照组有显著性差异(P<0.05)。8周训练后, 2.0 bl/s组丙二醛(MDA)含量显著低于其他3组(P<0.05), 而H₂O₂含量随着水流速度增加呈上升趋势。8周运动训练对骨骼肌B细胞淋巴瘤因子-2 (Bcl-2)、Bcl-2相关X蛋白(Bax)的含量及血清肌酸激酶(CK)活性无显著影响(P>0.05), 但2.0 bl/s组Bax和Bax/ Bcl-2显著低于4.0 bl/s组(P<0.05)。结果表明, 2.0 bl/s的水流速度可提高中华倒刺鲃肌肉的抗氧化能力, 降低脂质过氧化水平, 并在一定程度上抑制肌细胞凋亡。

     

基于倍四元数和Groebner基的6R机械手的位置反解

提出了一般6R机械手的位置反解的新算法,该算法是把齐次变换矩阵转以倍四元数形式表示,建立了倍四元数形式的串联6R机械手运动学方程,再通过线性消元和两次应用分次字典序Groebner基消去5个变元,得到一个一元16次方程.此方法没有增根,是一种对空间任意尺寸6R机械手进行建模和求解的新算法.其中求解Groebner基采用了计算机代数系统进行有理数运算,目前的求解速度尚不是很高,需进一步改进.     

农机培训教案的编写

教案即教学方案,是教师进行教学的实施方案,是教学的一个重要环节,是教好课的重要保证。编写教案要力求规范与创新,认真贯彻基本编写原则,以达到更好的培训效果,提高教学质量。     

氮肥运筹模式对冬小麦氮素吸收利用的影响

为给小麦高产、高效、无污染及可持续生产提供合理的氮肥运筹技术和理论依据, 以烟农19为材料,在大田条件下,研究了不同施氮量和基追比例对土壤小麦系统氮素积累及分配的影响。结果表明,施氮可提高0~100 cm土体内的全氮含量。在小麦越冬前, 0~40 cm土层中NO3-N含量随氮肥用量和基肥比例的增加显著增加;起身期到拔节期,施氮量为180和240 kg·hm-2且基肥∶拔节肥∶孕穗肥为3∶5∶2处理的0~40 cm土层内NO3-N含量下降,而施氮量为240 kg·hm-2且基肥∶拔节肥为7∶3和5∶5的处理及施氮量为300 kg·hm-2且基肥∶拔节肥为7∶3的处理则显著增加;拔节期到成熟期,随施氮量的增加,0~60 cm土层速效氮增加幅度有所提高。孕穗肥可明显提高灌浆期的植株全氮含量。因此,在240 kg·hm-2 施氮水平、基肥∶拔节肥∶孕穗肥为3∶5∶2条件下,施氮既能减少土壤硝态氮累积量,又能有效降低土壤硝态氮污染地下水的可能性。     

施肥量与氮肥基追比对西农979产量和品质的效应

为给小麦品种西农979的优质高产栽培提供理论依据,在高、中两种施肥量(高肥:每公顷施纯氮270kg、P2O5 225 kg、K2O 120 kg;中肥:每公顷施纯氮180 kg、P2O5 120 kg、K2O 120 kg)和氮肥7:3、6:4、5:3 :2、10:0四种基追比例(一次追氮在拔节期进行,两次追氮分别在拔节期与孕穗期进行)条件下,研究了施肥量和氮肥基追比例对西农979产量和品质的影响.结果表明,高肥处理产量比中肥处理产量提高9.66%;无论在中肥或高肥条件下,籽粒产量均随氮肥追施比例的增加而提高.施肥量和氮肥基追比例对千粒重的影响较小,对穗粒数的影响居中,对群体穗数的调控作用较大.氮肥基追并施可显著提高成穗率.随施肥量的提高和氮肥追施比例的加大,群体穗数逐渐增加,籽粒蛋白质含量和湿面筋含量也有逐渐提高的趋势,但蛋白质含量增幅小,湿面筋含量增幅大.高施肥量下,氮肥基追比例5:3:2,西农979的籽粒产量、蛋白质含量和湿面筋含量最高,分别达到8 573.5 kg·hm-2、14.97%和32.12%.     

都市园艺应用型人才实践教学体系的构建

以金陵科技学院园艺学院为例,从构建序列化技能训练的实践教学体系、提高都市园艺人才的职业素能及提升学生创新、创业实践能力几个方面对都市园艺应用型人才实践教学体系进行了构建。     

水稻矮秆突变体Zj88d的鉴定与基因定位

 用甲基磺酸乙酯诱变处理常规粳稻浙粳88,获得了矮秆水稻突变体Zj88d,多代自交稳定遗传。遗传分析表明突变体Zj88d的矮秆性状受一对隐性核基因控制。采用图位克隆方法,将目的基因定位在水稻第7染色体短臂末端7 44w和RM5344间的603 kb区间。排查该区间包含的100个候选基因,发现已克隆的矮秆基因OSH15也位于其中。测序结果显示,突变体Zj88d中的OSH15基因在第2内含子最末位发生“g→a”单碱基突变。     

Relationship Between the First Base of the Donor Splice Site of Waxy Gene Intron 1 and Amylose Content in Yunnan Indigenous Rice Varieties

There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT-genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content (18.95% on average) than those with TT-genotype (all below 16%), but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 (P<0.01).