烟草品种、育苗方式和烟蚜来源对烟蚜茧蜂寄生能力的影响

【目的】本研究旨在筛选出适合烟蚜茧蜂Aphidius gifuensis寄生烟蚜Myzus persicae的烟草品种、育苗方式和烟蚜来源,为烟蚜茧蜂人工繁殖和复壮提供科学参考。【方法】采用盆栽法,调查了不同烟草品种(云烟87、K326、翠碧1号和红花大金元)繁殖烟蚜若蚜、不同来源烟蚜(来自烟区、来自非烟区和室内繁殖种群)若蚜和烟草不同育苗方式(土壤育苗和湿润育苗)繁殖烟蚜若蚜时,烟蚜茧蜂成蜂对烟蚜若蚜的寄生率以及成蜂羽化率、寿命、体型大小和雌蜂比。【结果】结果表明,不同烟草品种繁殖烟蚜若蚜对烟蚜茧蜂成蜂寄生率存在显著影响。其中,在红花大金元和翠碧1号繁殖烟蚜上的烟蚜茧蜂成蜂寄生率分别比在K326繁殖烟蚜上的烟蚜茧蜂成蜂寄生率高19.00%和14.00%,但对烟蚜茧蜂的其他指标没有显著影响;不同烟蚜来源对烟蚜茧蜂寄生率也存在显著影响,其中,烟蚜茧蜂成蜂对非烟区烟蚜若蚜和烟区烟蚜若蚜的寄生率比对室内繁殖种群烟蚜若蚜的寄生率分别高20.25%和16.75%,但对烟蚜茧蜂成蜂的羽化率、寿命、体型大小和雌蜂比没有显著影响;烟草不同育苗方式对烟蚜茧蜂成蜂的寄生率无显著影响。【结论】烟蚜茧蜂对烟蚜...     

中国旧石器原料开发策略的研究进展

石料开发与获取是石器生产操作链的重要环节,也是史前人地关系研究的重要内容,能够反映史前人类的资源开发策略、环境认知与适应能力、移动模式和交流贸易网络等。相比于旧大陆西侧,东亚地区的燧石和黑曜岩等优质石料产地相对稀缺,中国许多旧石器考古遗址的石器原料主要来自遗址周边质量欠佳的脉石英、石英岩和一般燧石等,而相关的旧石器时代石料开发策略系统研究也相对较少。本文对中国目前已开展的旧石器时代石料开发策略研究进行系统梳理分析和总结发现,从旧石器时代早期到晚期末段,中国境内史前人类的石料开发策略存在明显的时空变化,主要体现在石料类型组成、产地选取和开发方式三个方面,可能主要受到史前人类流动性变化、石器技术演变和环境变化等因素的共同影响。综合而言,开展旧石器时代遗址的石料开发策略研究,对于理解中国境内史前人类的行为模式和交流迁徙等有重要意义。     

外源硫化氢对盐碱胁迫下裸燕麦叶片有机酸和激素含量的影响

为探讨外源硫化氢（H₂S）对盐碱胁迫下植物有机酸和激素水平的调控效应,以裸燕麦（Avena nuda）为材料,研究喷施50 μmol·L^-1 H₂S供体硫氢化钠（NaHS）溶液对3.00 g·kg^-1盐碱胁迫下叶片有机酸、激素含量和产量性状的影响。结果表明：盐碱胁迫显著提高了琥珀酸、丁烯二酸、苹果酸、葡萄糖醛酸和总有机酸含量,显著降低了焦谷氨酸、茉莉酸-异亮氨酸（JA-Ile）、反式-玉米素（tZ）和N⁶-（Δ²-异戊烯）腺嘌呤（iP）含量。喷施NaHS溶液显著提高盐碱胁迫下裸燕麦叶片中3-羟基-3-甲基谷氨酸、吲哚乙酸（IAA）、赤霉素A₇（GA₇）、茉莉酸甲酯（MJA）、iP含量和IAA/ABA比值,显著降低葡萄糖醛酸、赤霉素A₃（GA₃）、赤霉素A₄（GA₄）、总赤霉素（GA_S）、1-氨基环丙烷羧酸（ACC）含量和ACC/ABA比值,而对琥珀酸、丁烯二酸、苹果酸、柠檬酸、丙二酸、泛酸、烟酸、焦谷氨酸、辛二酸、苯丙酮酸、总有机酸、赤霉素A₁（GA₁）、茉莉酸（JA）、JA-Ile、脱落酸（ABA）、tZ、反式-玉米素核苷（tZR）、N⁶-（Δ²-异戊烯基）腺苷（iPA）、总茉莉酸类（JAs）、细胞分裂素（CTK）含量、GAs/ABA、JAs/ABA、CTK/ABA比值无显著影响。主成分分析表明,喷施NaHS溶液使盐碱胁迫下裸燕麦叶片中有机酸3-羟基-3-甲基谷氨酸和激素MJA、GA₇、tZ、IAA含量分别显著上调14.31%和41.83%、50.00%、22.97%、13.02%;而有机酸烟酸、葡萄糖醛酸和激素GA₄、ACC、tZR、GA₃含量分别显著下调16.00%、23.87%和73.53%、32.72%、50.00%、33.91%。另外,喷施NaHS溶液使盐碱胁迫下裸燕麦千粒质量下降了5.91%,而穗数量、穗铃数量、穗粒数量和籽粒产量分别提高了2.19%、9.70%、61.60%和52.83%。表明外源H₂S参与盐碱胁迫下裸燕麦有机酸和激素水平的调控,能够增强裸燕麦适应盐碱胁迫的能力。     

耐高温α－淀粉酶在生产超高麦芽糖浆中应用的研究

本文着重研究了耐高温α－淀粉酶与ＢＦ—７６５８α－淀粉酶（即普通中温淀粉酶）在超高麦芽糖浆生产中的区别。使用耐高温α－淀粉酶可使淀粉液化更完全,并且可降低酶的用量,同时生产的超高麦芽糖浆中麦芽糖含量大大提高,具有一定的推广、使用价值。     

准分子激光治疗近视眼

本文对准分子激光PRK治疗近视眼息者503例的早期临床结果进行分析,近视范围为－2．0至－15．0D,根据术前屈光度不同分为三组,术后随访三个月．结果证实准分子激光是一种安全、有效、预测性较好的治疗近视眼方法．全部病人提高了裸眼视力,绝大部分保持了最佳矫正视力,且没有产生危及视力的并发症．     

Differential requirement of protein tyrosine kinase and protein kinase C in the generation of IL-2-induced LAK cell and αCD3-induced CD3-AK cell responses

This study examined the role of protein tyrosine kinase (PTK) and protein kinase C (PKC) in the signal transduction pathways for lymphocyte activation through IL-2R to generate LAK cells and through TCR—CD3 to generate CD3-AK cells. Two PTK inhibitors [herbimycin A and genistein (PTK-I)] and two PKC inhibitors [calphositin C and staurosporine (PKC-I)] were used in the experiments. It was found that the primary activation pathway through IL-2R was PTK-dependent; that is, generation of both the IL-2-induced proliferative and the cytotoxic responses was completely abrogated by PTK-I and not by PKC-I. Quite different results were obtained with the αCD3-induced CD3-AK cell response. First, the αCD3-induced proliferation was only partially inhibited by PTK-I or PKC-I alone. Second, generation of CD3-AK cytotoxic response was primarily PKC-dependent; that is, only PKC-I induced significant inhibition. Genistein was found to reduce protein tyrosine phosphorylation in both LAK cells and CD3-AK cells, indicating that CD3-AK cells were also susceptible to PTK-I treatment. Further studies showed that PTK-I and not PKC-I suppressed perforin mRNA expression and N-2-benzyoxycarbonyl-l-lysine thiobeneylester esterase production in LAK cells, and the opposite was true for CD3-AK cells. These results indicate that different pathways were employed in lymphocyte activation through IL-2R and TCR—CD3. The former pathway is primarily PTK-dependent. Activation through TCR—CD3 is a more complex event. Induction of a proliferative response can employ either a PTK- or a PKC-dependent pathway, whereas induction of a cytotoxic response is primarily PKC-dependent. Furthermore, it appears that a PTK-independent pathway exists for the induction of a CD3-AK response and thus suggests that activation of the second messenger PKC may not necessarily be preceded by PTK activation.     

Incipient Speciation by Sexual Isolation in Drosophila Melanogaster: Extensive Genetic Divergence without Reinforcement

The collection of Drosophila melanogaster from Zimbabwe and nearby regions (the Z-type) yield females who would not mate with the cosmopolitan D. melanogaster males (the M-type). To dissect the genetic basis of this sexual isolation, we constructed 16 whole-chromosome substitution lines between two standard Z-and M-lines. The results were as follows: (1) All substitution lines appear normal in viability and fertility in both sexes, indicating no strong postmating isolation. (2) The genes for the behaviors are mapped to all three major chromosomes with the same ranking and comparable magnitude of effects for both sexes: III > II >> X >/= 0 (III, II and X designate the effects of the three chromosomes). The results suggest less evolution on the X than on autosomes at loci of sexual behavior. (3) The genes for ``Z-maleness' are many and somewhat redundant. Whole-chromosome effects for Z-maleness appear nearly additive and show little dominance. (4) In contrast, ``Z-femaleness' has less redundancy as partial genotypes never exhibit full phenotypic effects. Epistatic interactions and incomplete dominance can sometimes be detected. (5) The extensive genetic divergence underlying sexual isolation has evolved in the absence of detectable reduction in hybrid fitnesses. Sexual selection has apparently been a driving force of multiple facets of speciation at the nascent stage without reinforcement.     

南方红豆杉叶精油化学成分的研究

采用水蒸汽蒸馏法提取南方红豆杉叶的精油,通过色谱－质谱－计算机联用技术分析了精油的化学成分。从中初步鉴定出２６个化合物,占精油总量的９６％,主要成分是：棕榈酸（３５．６６％）,９－十六碳烯酸９－十六碳稀酯（１１．２８％）,３－辛醇（４．４７％）,１－苯－１,２－丙二酮（４．３％）,Ｎ－苯基－１－萘胺（３．５７％）,１,２－苯二羧酸（２－甲基丙基）二酯（３．５７％）,６,１０－二甲基－５,９－十一双     

三尖杉叶精油化学成分的研究

三尖杉叶精油化学成分的研究苏应娟,王艇,张宏达（中国科学院武汉植物研究所武汉４３００７４）（中山大学生命科学学院广州５１０２７５）关键词三尖杉,精油,化学分类ＡＳＴＵＤＹＯＮＣＨＥＭＩＣＡＬＣＯＮＳＴＩＴＵＥＮＴＳＯＦＥＳＳＥＮＴＩＡＬＯＩＬＦＲＯＭ...