两种鲷属鱼类线粒体COI基因片段序列的比较

利用通用引物成功扩增了黄鳍鲷和黑鲷的线粒体细胞色素氧化酶Ⅰ亚基（COI）基因序列。通过序列测定，得到581bp的基因片段，碱基A、T、G、C平均含量分别为25．8％、32．6％、18．0％和23．6％，序列中的A＋T含量明显高于G＋C含量，与其他鱼类的C01基因片段研究结果相一致。通过序列分析发现黄鳍鲷和黑鲷两序列共存在14处碱基变异，其中在第19～139bp之间检测到13个变异位点，是变异频率较高的区段，可以考虑作为鲷属或者种群鉴别的分子标记。与黄鲷、真鲷、三长棘真鲷等鱼类比较，无插入和缺失位点，转换明显高于颠换。序列差异比较结果显示，真鲷与黄鳍鲷的序列差异在这5种鱼类中最大，达到了18．2％，黄鳍鲷和黑鲷的筹异最小（2．4％）。两个序列已提交到GenBank数据库中．序列臀录号为DQ185608和DQ185609.     

小麦多酚氧化酶(PPO)活性的SSR标记筛选与验证

小麦多酚氧化酶(PPO)活性是引起面条和面团储存期间颜色褐变的主要因素。发掘可应用于籽粒PPO活性辅助选择的分子标记，将有助于小麦面粉颜色性状的遗传改良。本研究选用来自全国不同麦区的203份冬小麦品种，验证SSR(simple sequence repeat)引物Xgwm312的PCR扩增片段大小与籽粒PPO活性的关系。结果表明，198bp扩增片段的有无同籽粒PPO活性大小密切相关，该片段的出现通常意味着籽粒PPO活性较高。Xgwm312可应用于籽粒PPO活性的分子标记辅助育种。     

基因型和地点对小麦品种面粉多酚氧化酶活性的影响研究

 试验对1999年度种植在长江中下游11个代表性试点的22个小麦主栽品种进行了面粉多酚氧化酶(PPO)活性影响因素研究。结果表明，基因型、环境及其互作对PPO活性的影响达到1%显著水平。面粉L*值与PPO活性呈1%显著负相关，r值为-0.55，容重和淀粉糊化品质指标与PPO活性呈5%或1%显著负相关，籽粒硬度、面粉b*值、沉降值以及吸水率、稳定时间与PPO活性呈5%正相关，r值分别为0.57、0.69、0.46、0.42和0.46，而千粒重、籽粒直径、出粉率、灰分和蛋白质含量以及面团拉伸特性与PPO活性相关不显著。     

双低油菜农杆菌介导法导入草酸氧化酶基因研究

草酸氧化酶基因(OxO)可将草酸转化为CO2和H2O2,为研究草酸氧化酶基因对植物抗病的作用,本文通过根癌农杆菌(Agrobacterium tumefaciens)介导途径,将草酸氧化酶基因导入了双低油菜,经过诱导分化获得抗卡那霉素抗性的再生植株。经PCR检测得到了与阳性对照一致的470 bp的片段,初步表明OxO基因已整合进油菜基因组中。在诱导接种实验和对草酸的耐受性实验中,转基因油菜植株的抗性明显高于未转化油菜。     

牵牛子种子提取物对朱砂叶螨触杀活性的测定

 【目的】研究牵牛子石油醚提取物中流分8对朱砂叶螨生物活性的作用机理。【方法】采用玻片浸渍法和叶片残毒法测定了流分8对朱砂叶螨成螨和卵的室内毒力,并采用生化方法测定了谷胱甘肽-S-转移酶、乙酰胆碱酯酶、单胺氧化酶、Ca2+-ATP酶活性的影响,通过透射电镜观察流分8对螨体内亚显微结构的破坏。【结果】流分8对朱砂叶螨成螨和卵均有很强的生物活性,对成螨和卵的LC50分别是0.4686 mg?ml-1和1.2212 mg?ml-1,LC90分别是2.5935 mg?ml-1和3.1234 mg?ml-1。牵牛子流分8处理朱砂叶螨后,螨体内解毒酶谷胱甘肽-S-转移酶被激活,这说明流分8中存在对朱砂叶螨有毒的物质;而乙酰胆碱酯酶、单胺氧化酶、Ca2+-ATP酶均受到不同程度的抑制,这可能引起神经传递的阻断,从而导致螨体的死亡。透射电镜下可见,流分8对螨体内表皮结构、肌纤维、细胞核膜、线粒体、内质网等均有不同程度的破坏。【结论】牵牛子可以有效杀死朱砂叶螨,作为新型植物源农药具有一定的开发价值。     

联苯肼酯与炔螨特混配对朱砂叶螨的联合毒力作用

为了科学合理使用2008年在中国获得登记的新型酰基乙腈联苯肼类杀螨剂联苯肼酯,延长其使用寿命,本研究采用生物测定法和紫外分光光度法针对性地开展了联苯肼酯与炔螨特混配对朱砂叶螨的联合毒力作用评价。结果表明,43%联苯肼酯悬浮剂和73%炔螨特乳油按有效成分215∶73混配对朱砂叶螨的共毒系数为163.0,共毒系数大于120,表现出良好的增效作用,经其20.00、14.29、11.11、9.09和7.69 mg/L的浓度处理24 h后,朱砂叶螨的谷胱甘肽S-转移酶(GST)活性显著降低,分别为3.371、3.645、3.932、4.045和4.089 mmol/(mg Pro·min),显著低于相同浓度联苯肼酯单剂[7.250、6.818、6.714、6.441、5.811 mmol/(mg Pro·min)]和炔螨特单剂[10.130、9.789、9.142、8.932、8.441 mmol/(mg Pro·min)],说明联苯肼酯与炔螨特混配对朱砂叶螨GST具有显著的联合抑制作用;经联苯肼酯与炔螨特混配液处理24 h后,朱砂叶螨的多功能氧化酶(MFO)、羧酸酯酶(Car E)和乙酰胆碱酯酶(Ach E)活性与联苯肼酯和炔螨特单剂处理的结果无显著差异。本研究结果为合理混配使用联苯肼酯与炔螨特防治朱砂叶螨的发生与危害提供了理论依据。     

草莓中贝壳杉烯氧化酶基因( STGA3)中两个不同编码序列的克隆

 以保守氨基酸序列设计了简并性引物的方法, 克隆‘丰香’草莓( Fragaria gradiflora‘Fengxiang’) 贝壳杉烯氧化酶基因部分序列, 发现叶片和花蕾中合成赤霉素的贝壳杉烯氧化酶的序列不同, Southern杂交方法检测在草莓基因组中存在3个拷贝的目标基因, 表明在草莓中至少有两个不同基因共同编码贝壳杉烯氧化酶, 以响应不同发育信号的调控。     

Protoporphyrinogen oxidase-inhibiting activity of the new,wheat-selective isoindoldione herbicide,cinidon-ethyl

Cinidon-ethyl (BAS 615H) is a new herbicide of isoindoldione structure which selectively controls a wide spectrum of broadleaf weeds in cereals. The uptake, translocation, metabolism and mode of action of cinidon-ethyl were investigated in Galium aparine L, Solanum nigrum L and the tolerant crop species wheat (Triticum aestivum L). When plants at the second-leaf stage were foliarly treated with cinidon-ethyl equivalent to a field rate of 50 g ha⁻¹ for 48 h, the light requirement for phytotoxicity and the symptoms of plant damage in the weed species, including rapid chlorophyll bleaching, desiccation and necrosis of the green tissues, were identical to those of inhibitors of porphyrin synthesis, such as acifluorfen-methyl. The selectivity of cinidon-ethyl between wheat and the weed species has been quantified as approximately 500-fold. Cinidon-ethyl strongly inhibited protoporphyrinogen oxidase (Protox) activity in vitro, with I₅₀ values of approximately 1 nM for the enzyme isolated from the weed species and from wheat. However, subsequent effects of herbicide action, with accumulation of protoporphyrin IX, light-dependent formation of 1-aminocyclopropane-1-carboxylic acid-derived ethylene, ethane evolution and desiccation of the green tissue, were induced by cinidon-ethyl only in the weed species. After foliar application of [¹⁴C] cinidon-ethyl, the herbicide, due to its lipophilic nature, was rapidly adsorbed by the epicuticular wax layer of the leaf surface before it penetrated into the leaf tissue more slowly. No significant differences between foliar and root absorption and translocation of the herbicide by S nigrum, G aparine and wheat were found. After foliar or root application of [¹⁴C]- cinidon-ethyl, translocation of ¹⁴C into untreated plant parts was minimal, as demonstrated by combustion analysis and autoradiography. Metabolism of [¹⁴C]cinidon-ethyl via its E-isomer and acid to further metabolites was more rapid in wheat than in S nigrum and G aparine. After 32 h of foliar treatment with 50 g ha⁻¹ of the [¹⁴C]-herbicide, approximately 47%, 36%, and 12% of the absorbed radioactivity, respectively, were found as unchanged parent or its biologically low active E-isomer and acid in the leaf tissue of G aparine, S nigrum and wheat. In conclusion, cinidon-ethyl is a Protox-inhibiting, peroxidizing herbicide which is effective through contact action in the green tissue of sensitive weed species. It is suggested that a more rapid metabolism, coupled with moderate leaf absorption, contribute to the tolerance of wheat to cinidon-ethyl. © 1999 Society of Chemical Industry     

Strain-specific vital rates in four Acartia tonsa cultures, I: Strain origin, genetic differentiation and egg survivorship

Successful development of planktonic copepods for use as live feed in marine aquaculture relies on optimization of environmental conditions for population growth and egg storage. This study examined strain-specific differences in egg survivorship during cold-storage-induced quiescence in four cultures of the widespread marine calanoid Acartia tonsa Dana, 1849. Experimental cultures were obtained from Øresund, Denmark (DIFRES), Kiel, Germany (KIEL), Turkey Point, Florida, USA (FL), and Mobile Bay, Alabama, USA (AL), and were shown to derive from three highly distinct mitochondrial clades. Eggs from Gulf of Mexico strains had low tolerance for cold storage, and showed very low hatching success after 10 days. In contrast, Baltic Sea strains produced eggs able to tolerate up to 150 days of cold storage, with the DIFRES strain showing the highest egg survivorship during the experiment. Eggs from the Kiel strain showed an increase in hatching over time, indicating the presence of dormant eggs. Parental rearing temperature was also found to affect egg survivorship during quiescence in the DIFRES strain, with lower hatching success observed among eggs produced at 25 °C than at 17 °C. The DIFRES strain is recommended as the optimal strain for use in aquaculture, and conditions for cold storage of eggs are discussed.     

基于线粒体CO I基因序列的棘头梅童鱼7个野生群体遗传结构分析

利用线粒体CO I序列为遗传标记分析了棘头梅童鱼(Collichthys lucidus Richardson)7个地理群体(江苏连云港、江苏大丰、上海崇明、浙江舟山、浙江温州、福建宁德和福建厦门)的遗传结构特征。在7个群体209个样本的线粒体CO I序列中共检测到44种单倍型。7个群体单倍型多样性为(0.416±0.112)~(0.720±0.076),核苷酸多样性为(0.001 10±0.000 35)~(0.004 44±0.001 64)。两个组群的AMOVA分析显示,南北两个组群分析组群间的变异为40.10%(P0.01),组群间群体间的为–0.15%(P0.05),群体内为60.05%(P0.05),这与基于单倍型构建的NJ树、基于群体间遗传距离构建的UPGMA树的结果均表明棘头梅童鱼群体具有明显的谱系结构,以温州为分界点,温州以北为北方类群,以南则为南方类群。两群体之间的基因流数据表明南方与北方类群的基因交流受阻,结合各方面资料,推测更新世的演化历史因素为棘头梅童鱼南北分支形成的主要原因,而自身的生活习性则是南、北类群内部无明显分化的原因。其结果可以为合理开发和利用棘头梅童鱼野生资源,以及建立和保护棘头梅童鱼种质资源提供必要的参考。