鬼臼类植物产鬼臼毒素内生真菌的筛选

从桃儿七(Sinopodoph yllum hexandrum)、南方山荷叶(Diphylleia sinensis)和川八角莲(Dysos-ma veitchii)中分离到92株内生真菌,其发酵提取物经TLC、HPLC,结果表明,6株内生真菌能产鬼臼毒素,占总分离菌株数的6．5％。桃儿七、南方山荷叶和川八角莲内生真菌中产鬼臼毒素菌株占各供测菌株的7％,3％和10％。     

小檗科鬼臼亚科植物的核型研究

本文首次报道了中华山荷叶与川八角莲的核型,分别为Ｋ（２ｎ）＝１２＝８ｍ（４ＳＡＴ）＋２ｓｔ＋２ｔ及Ｋ（２ｎ）＝１２＝４ｍ（２ＳＡＴ）十４ｓｍ＋２ｓｔ（２ＳＡＴ）＋２ｔ,核型类型均为ＺＡ型。本文报道的桃儿七及八角莲的核型与前人的结果有一定差异,前者为：Ｋ（２ｎ）＝１２＝６ｍ（４ＳＡＴ）＋２ｓｍ＋２ｓｔ＋２ｔ,２Ｂ型,后者为Ｋ（２ｎ）＝１２＝８ｍ（２ＳＡＴ）＋２ｓｔ（２ＳＡＴ）＋２ｔ,为２Ａ型。本文分析了小檗科鬼臼亚科４个属共７种植物的核型,结果是该类植物的核型极为相似,染色体数目均为２ｎ＝１２,由８条ｍ或ｓｍ,２条ｓｔ以及２条ｔ染色体组成。核型的相似性反映了这类植物的亲缘关系,这４个属的植物是一个自然类群。但随着系统发育,核型的不对称性有所增加,其中以山荷叶属最为对称,八角莲属居中,桃儿七属与足叶草属最不对称。笔者认为,核型上的高度相似是该类植物在系统发育上不发达,属内种类稀少,通常为寡种属或单种属的重要原因。     

深红蔓绿绒的组织培养与快速繁殖

１　植物名称　深红蔓绿绒（Ｐｈｉｌｏｄｅｎｄｒｏｎｍａｎｄａｉａｎｕｍ“ＲｏｙａｌＱｕｅｅｎ”）。２　材料类别　顶芽、侧芽。３　培养条件　以ＭＳ为基本培养基。（１）芽体启动培养基：ＭＳ＋６ＢＡ２ｍｇ·Ｌ－１（单位下同）＋ＮＡＡ０．０１;（２）不定芽增殖培养基：ＭＳ＋６ＢＡ３～４＋ＮＡＡ０．１;（３）生根培养基：１／２ＭＳ＋６ＢＡ０．５＋ＩＢＡ２。以上培养基均加琼脂７．５ｇ·Ｌ－１,ｐＨ值为５．８,培养室温度（２６±２）℃,光照度１０００ｌｘ,每日光照时间１２ｈ。培养基（１）与（２）中蔗糖用…     

[^3H]Cortisol及[^3H]Dexamethasone在大鼠肝细胞膜上的特异结合位点

本研究应用［３Ｈ］ｃｏｒｔｉｓｏｌ和［３Ｈ］ｄｅｘａｍｅｔｈａｓｏｎｅ（ＤＥＸ）两种配基,观察到大鼠肝细胞膜上存在一类糖皮质激素（ＧＣ）特异结合位点。这些位点与ＧＣ的结合具有饱和性、高亲和力及低容量。其平衡解离常数（Ｋｄ）分别为１２．８４±６．５８ｎｍｏｌ／Ｌ和４０．２７±２３．４４ｎｍｏｌ／Ｌ;最大结合容量（Ｂｍａｘ）分别为２．５７±１．８４ｐｍｏｌ／ｍｇ蛋白质与０．６４±０．１８ｐｍｏｌ／ｍｇ蛋白质（ｃｏｒｔｉｓｏｌ,ｎ＝４;ＤＥＸ,ｎ＝３;±ＳＥ）。动力学实验数据所得的Ｋｄ值与Ｓｃａｔｃｈａｒｄ分析所得的Ｋｄ值结果基本一致。［３Ｈ］ｃｏｒｔｉｓｏｌ和［３Ｈ］ＤＥＸ饱和结合实验数据用Ｓｃａｔｃｈａｒｄ作图分析,均显示为直线。Ｈｉｌｌ系数则分别为０．９８８０和０．９９９０．竞争抑制实验结果表明,ｃｏｒｔｉｓｏｌ对［３Ｈ］ｃｏｒｔｉｓｏｌ的结合位点有高度特异性竞争,比其它几种类固醇（强的松、黄体酮、ＲＵ４８６、ＤＥＸ）的竞争力至少强４０倍以上．用放射自显影技术进行研究,也提供了［３Ｈ］ｃｏｒｔｉｓｏｌ特异结合银粒位于大鼠肝细胞膜上的依据。     

根田鼠的最大同化能量

本文利用逐步降温诱导，以食物平衡法对青海高原的根田鼠（Ｍｉｃｒｏｔｕｓ ｏｅｃｏｎｏｍｕｓ）的最大同化能量进行了测定，设有５个实验温度；２３℃，１５℃，１０℃，５℃和３℃，结果显示每个动物每天能量摄入于 ５℃大， １９７． １４±８．６６ＫＪ；同样，消化能、消化率、同化能和同化率也于 ５℃８大，分别为１２３．９６±１３．０５ＫＪ，６３．０±４．８％，１２１．７７±１３．５２ＫＪ和５１．４±５．２％；消化率与同化率３℃最小，分别为５１．５±３．９％和５０．４±４．０％．根田鼠的最大同化能量为基础代谢率（ＢＭＲ）的３．２—３．５倍，明显高于以平均每日代谢率（ＡＤＭＲ）估测的每日能耗，故在自然生境中根田鼠的能量收支很少达到其生理上限，其生存价较高．     

矮生鸡冠花的离体快繁及试管苗开花

１植物名称矮生鸡冠花（Ｃｅｌｏｓｉａｃｒｉｓｔａｔａ）。２材料名称无菌种子苗顶芽、腋芽。３培养条件基本培养基为ＭＳ。培养基组合为：（１）ＭＳ＋ＢＡ１－２ｍｇ·Ｌ~（－１）（单位下同）＋ＮＡＡ０．１～０．２;（２）ＭＳ＋ＢＡ２＋ＩＡＡ０．２;（３）ＭＳ＋ＫＴ２;（４）ＭＳ＋ＢＡ０．１～０．５。以上培养基均含３％蔗糖,０．６％琼脂,ｐＨ为５．８,培养温室为（２６±２）℃,光照１２ｈ．ｄ~（－１）（２０００ｌｘ）。４生长与分化情况４．１无菌材料的获得成熟的种子置７０％酒精中摇动５０ｓ后,转入饱和漂白粉溶…     

DOCA—Salt高血压大鼠模型的一种简易制备方法：DOCA硅胶管皮下埋入法

用外径４ｍｍ,内径２．５０ｍｍ的硅胶管制成长２５ｍｍ,管内填入ＤＯＣＡ１００ｍｇ,管壁钻有１０一１４个直径约３００μｍ微孔的药管,埋入雄性ＳＤ大鼠（１４０±９ｇ）右下腹皮下,摘除一侧肾脏,术后喂１％盐水。埋管后３周即可形成高血压,埋管后８周大鼠的收缩压达２３．３±０．３７ｋＰａ。而ＤＯＣＡ皮下注射组大鼠（１０ｍｇ／周）术后５周形成高血压,术后１３周大鼠的收缩压达２３．３±０．６６ｋＰａ。两组升压曲线回归系数（１．２９５和０．６９２）之间的差异有极显著性意义（Ｐ＜０．００１）。对照鼠的收缩压一直保持在正常水平（１６±０．１６ｋＰａ）。与ＤＯＣＡ皮下注射法相比,皮下埋管法具有两个显著优点：（１）升压速率较快,升压幅度较大;（２）方法简便可靠,重复性好。     

P物质对GABAA和GABAB受体介导的DRG神经元膜反应的调制作用

实验在幼年大鼠ＤＲＧ标本上进行。应用细胞内记录观察了ＳＰ对ＧＡＢＡ反应的调制作用。结果证明：（１）单独滴加ＳＰ（５×１０（－６）－４×１０（－５）ｍｏｌ／Ｌ）或浴槽灌流ＳＰ（１０（－６）－５×１０（－６）ｍｏｌ／Ｌ）不引起膜电位的改变或仅有轻微的去极化,但却能使ＧＡＢＡ引起的去极化反应减小５０．８±２０．２％（±ＳＤ）（２０／３０）;（２）单独滴加ＳＰ可使多数受检细胞ＡＰＤ５０延长２８．７±９．１％（±ＳＤ）（１０／１８）;（３）在预加ＳＰ后,能使ｂａｃｌｏｆｅｎ所引起的ＡＰＤ５０缩短效应（２０．６±２．９％,±ＳＤ）完全消除（４／１２）或翻转成ＡＰＤ（５０）延长１９．３±８．９％（±ＳＤ）（８／１２）;（４）预加ＧＡＢＡＢ受体激动剂ｂａｃｌｏｆｅｎ（１０（－４）－１０（－３）ｍｏｌ／Ｌ）３０—９０ｓ后明显地抑制ｍｕｓｃｉｍｏｌ（１０－４－１０－３ｍｏｌ／Ｌ）引起的去极化反应,其抑制效应达５４．４±１８．８％（±ＳＤ）（１７／２０）。由于ＤＲＧ神经元的胞体通常可用来作为研究初级传入终末的模型,因而本文实验结果提示：介导伤害性刺激信息的Ｐ物质在背角的释放,可能作用于初级传入终末,从而产生对抗ＧＡＢＡ介导的突触     

小鼠卵慢速和快速降温及玻璃化冻存的比较研究

本文用４种冷冻模式：慢速降温（ＳＬ）,超快速降温（Ｑ１）和防冻剂组成不同的玻璃化法（Ｒ－ＦＶＭ和ＭＶＭ）对昆明小鼠卵进行冷冻保存的比较研究,并用体外受精技术检测冷冻复苏卵的受精能力。ＳＬ和Ｒ－ＦＶＭ的存活率分别为５５．１±１．２和６５．９±７．９,显著高于Ｑ１（２４．２±７．３）和ＭＶＭ（４．５±２．４）其受精率分别为７２．８±１．８和７３．９±０．４显著高于Ｑ１（５８．６±１１．２）和ＭＶＭ（４１．５±８．５）,而与对照组（７７．５±３．９）相似。结果表明：１）慢速降温程序（ＳＬ）和同时含有渗透性和非渗透性防冻剂的玻璃化法（Ｆ—ＲＶＭ）较适宜昆明小鼠卵的冻存;２）同时考虑冻存过程中的冰晶损伤和渗透压损伤是获得较好冻存结果的关键。     

评介Smnh等的热河群40Ae-39Ar同位素测年结果

对Ｓｍｉｔｈ等１９９５年热河群４０Ａｒ－３９Ａｒ同位素测年工作的背景以及各样品的采样地点、层位与测年目的等作了补充介绍．由于Ｓｍｉｔｈ等的论文中将３组后期火山岩的测年结果分别误解为义县组下部与上部地层的同位素年龄,因而整体上混淆了义县组不同层位的测年结果．Ｓｍｉｔｈ等１９９５年发表的６组样品的测年数据实际上至少代表了４个与热河群义县组相关层位的４０Ａｒ－３９Ａｒ同位素年龄：１２２．９±０．３Ｍａ（凌源大新房子沉积层下伏火山岩）、１２２．１±０．２～１２２．５±０．３Ｍａ（凌源二十里堡沉积层）、１２１．５±０．９～１２１．６±０．５Ｍａ（义县金刚山沉积层上覆火山角砾岩）、１２０．８±０．４～１２１．４±０．７Ｍａ（后期火山岩）。     

Latitude, seed predation and seed mass

Aim We set out to test the hypothesis that rates of pre‐ and post‐dispersal seed predation would be higher towards the tropics, across a broad range of species from around the world. We also aimed to quantify the slope and predictive power of the relationship between seed mass and latitude both within and across species. Methods Seed mass, pre‐dispersal seed predation and post‐dispersal seed removal data were compiled from the literature. Wherever possible, these data were combined with information regarding the latitude at which the data were collected. Analyses were performed using both cross‐species and phylogenetic regressions. Results Contrary to expectations, we found no significant relationship between seed predation and latitude (log₁₀ proportion of seeds surviving predispersal seed predation vs. latitude, P = 0.63; R² = 0.02; n = 122 species: log₁₀ proportion of seeds remaining after postdispersal seed removal vs. latitude, P = 0.54; R² = 0.02; n = 205 species). These relationships remained non‐significant after variation because of seed mass was accounted for. We also found a very substantial (R² = 0.21) relationship between seed mass and latitude across 2706 species, with seed mass being significantly higher towards the tropics. Within‐species seed mass decline with latitude was significant, but only about two‐sevenths, as rapid as the cross‐species decline with latitude. Results of phylogenetic analyses were very similar to cross‐species analyses. We also demonstrated a positive relationship between seed mass and development time across ten species from dry sclerophyll woodland in Sydney (P < 0.001; R² = 0.77; Standardized Major Axis slope = 0.14). These data lend support to the hypothesis that growing period might affect the maximum attainable seed mass in a given environment. Main conclusions There was no evidence that seed predation is higher towards the tropics. The strong relationship between seed mass and latitude shown here had been observed in previous studies, but had not previously been quantified at a global scale. There was a tenfold reduction in mean seed mass for every c. 23° moved towards the poles, despite a wide range of seed mass within each latitude.     

Co-evolution of seed size and seed predation

Using the evolutionarily stable strategy (ESS) approach in a model for the co-evolution of seed size and seed predation, I show that seed size variation within individual plants is favoured if there is a trade-off in the predator's attack rate for different seed sizes. A single seed size is not evolutionarily stable because a predator that is optimally adapted to one particular seed size cannot prevent invasion by plants with a different seed size. The model generates the following predictions. The ESS consists of a continuous range of seed sizes. Small seeds tend to be attacked more frequently than big seeds. Plants with many resources and plants with low (frequency-independent) juvenile mortality have more variable seeds than plants with few resources and a high juvenile mortality. Seed size variation is higher in fluctuating populations regulated by seed predation alone than in stable populations (partially) regulated by seedling competition. Predator searching behaviour does not directly affect the ESS seed size range, but may have an indirect effect by affecting population stability or the significance of seedling competition as a population regulating mechanism. Moreover, seed size distributions are found to be more skewed in favour of small seeds if predation is spatially non-uniform than if predation is more even. Application of the model to systems of several co-evolving plant and predator species is discussed.     

种壳厚度对鼠类种子扩散行为及种子命运的影响

种子扩散是植物更新和扩大分布区的一种重要途径。鼠类采取不同的种子扩散和贮藏策略,以应对食物短缺,同时也促进了植物种子扩散。为应对鼠类对植物种子的过度取食,种子进化出了一系列物理、化学等防御特征。其中种壳厚度作为一种物理防御策略,是影响鼠类贮藏行为和种子命运的关键因素。本研究拟通过去除天然栓皮栎（Quercus variabilis）种子的外壳,再在种仁外包被1、2、4、6不同层数的聚乙烯薄膜,模拟种壳厚度,准确控制种壳厚度。2020年10月—2021年1月,在四川都江堰森林生境中释放人工种壳包被的种子,研究人工种壳厚度对鼠类介导的种子扩散和命运的影响。结果表明：（1）鼠类优先扩散种壳较薄（1层薄膜包被）的人工种子;随着种壳厚度的增加,扩散速率逐渐降低,种壳最厚（6层薄膜包被）的种子扩散最慢（P < 0.001）;（2）鼠类喜好分散贮藏1层、2层薄膜包被的种子;当种壳厚度增加至包被4层、6层薄膜时,分散贮藏比例显著降低（P < 0.05）;（3）鼠类偏好集中贮藏4层薄膜包被的种子（P < 0.05）;（4）不同种壳厚度的种子扩散距离无显著差异（P > 0.05）;（5）种壳较薄（1层薄膜包被）的种子分散贮藏率在3 m范围内比例较高。采用聚乙烯薄膜包被是模拟种子外壳的可行方法,并可用于评估种壳厚度对鼠类种子贮藏行为和种子命运的影响等相关研究。     

昆虫种子捕食与蒙古栎种子产量和种子大小的关系

为了了解昆虫种子捕食者在栎类种群更新中的作用,于2006年秋季,在黑龙江省伊春市带岭区东方红林场研究了昆虫对蒙古栎Quercus mongolica在参园和东山两个种群的种子蛀食情况及其与蒙古栎种子产量和种子大小的关系。结果表明：(1)在参园和东山两个林分内,蒙古栎种子雨动态非常相似,种子雨成分中完好种子的平均密度仅为3.2±4.1个/m²（参园）和1.7±2.8个/m²（东山）,分别仅占种子产量的4.0％和3.2％,而虫蛀种子和败育种子的比例均在38%以上,以虫蛀种子的比例最高,分别为58.2％和57.7％;(2)柞栎象Curculio arakawai是蛀食蒙古栎种子的主要昆虫种类,在虫蛀种子中所占比例高达96.8％（参园）和97.1％（东山）,且象甲蛀食种子中所含虫卵数与种子大小有关,即种子越大,所含象甲的虫卵数就较多。本研究的结果说明2006年蒙古栎成熟种子多遭遇虫蛀,导致完好种子的数量极低,因而可能成为限制蒙古栎种群更新的重要因素。     

种子特征和结实量对啮齿动物取食和扩散种子行为的影响

为了深入了解啮齿动物在不同种子丰富度条件下对不同大小和单宁含量种子的觅食行为策略及其与植物种群更新的关系,在宁夏六盘山区的华北落叶松人工林,研究了不同大小和单宁含量[0%Tannin(T)、2%T、8%T和15%T]的人工种子在模拟结实小年和结实大年对啮齿动物取食和扩散行为的影响.结果表明: 啮齿动物消耗种子速度在结实小年更快,结实大年的种子消耗速度相对缓慢. 种子就地取食率(ISPR)在不同结实年份间无显著差异,扩散后取食率(PRAD)在结实小年显著高于结实大年,但前者的扩散后贮藏率(HRAD)显著低于后者;种子扩散后的取食距离(PDAD)和贮藏距离(HDAD)在结实小年均显著大于结实大年.在结实小年,大种子的PDAD和HDAD均大于小种子,前者在不同大小种子间均差异显著,而后者仅在2%T和15%T的不同大小种子间差异显著;在结实大年,除0%T外的其他单宁含量种子的PDAD和HDAD在不同大小种子间均差异显著.ISPR在中等单宁含量种子最大,高单宁含量种子最小;PRAD分别在结实小年的高单宁含量种子和结实大年的无单宁种子最大;不论在结实大年还是结实小年,HRAD均在高单宁含量种子最大,中等单宁含量种子最小.这说明结实大年可延缓啮齿动物对种子的消耗速率,提高种子的HRAD,但种子扩散距离减小;啮齿动物在结实大年和小年均表现出对大种子的扩散偏好,且大种子被扩散的距离更远;啮齿动物在不同结实年份均偏好于就地取食中等单宁含量种子,而扩散高单宁含量种子.     

Controls on seed production and seed germinability inEriophorum vaginatum

Controls on seed production in Eriophorum vagina tum were studied at two Low Arctic sites, Latnjajaure in Sweden and Toolik Lake in Alaska. At Latnjajaure, seed production was monitored for 3 years (1993-1995) in control plants and in plants that were experimentally warmed using ITEX open-topped chambers (OTCs). At Toolik Lake, experimental treatments included a factorial greenhouse x NP fertilizer experiment and artificial shading; data collection occurred in 1995, after eight seasons of treatment. Temperature differences between sites, years, and treatments all had significant effects on components of Eriophorum seed production. Pre-flo ration and post-floration times were decreased in warmer treatments and years. Ovule number per inflorescence was greater in warm years and at the warmer site, Toolik Lake. Although seed set was reduced in the OTCs at Latnjajaure, probably due to low pollination rates, in the larger greenhouses at Toolik Lake seed set was increased. The most consistent responses to temperature were in seed weight, where treatment effects were greatest at lower temperatures, such that, for example, at Latnjajaure the increases in seed weight in the OTCs were greatest in the coldest year. Fertilizer treatment had no significant effect on seed number or weight at Toolik Lake, and in the fertilizer + greenhouse treatment there were no inflorescences because Eriophorum had been nearly eliminated from the treated plots. In the shade treatment at Toolik Lake, inflorescences were fertilized but only a single mature seed was collected. Overall, the results indicate that seed production by E. vagina tum is strongly responsive to environmental variation and that only a small increase in mean summer temperatures would result in a much larger and more stable seed production.     

Pre-dispersal seed predation and seed limitation in an annual legume

The basic idea of the source simulation technique is to replace the scatterer (or radiator by a system of simple sources located within the envelope of the original body. The extent to which the simulated field reproduces the original field depends on the degree of correspondence between the simulated and the given boundary conditions. Numerical simulations have shown that: (1) the shape of the auxiliary surface, (2) the number of sources, and (3) the way the sources are distributed are the most relevant parameters to ensure an accurate solution for the problem. In the case of the single-layer method, sources should not be positioned close to the center of the body, because the problem becomes ill-conditioned. The auxiliary surface and the scatterer should be as similar as possible in order to minimize the boundary error. With respect to the number of sources (N), there are two opposite effects: (1) if (N) is too small, the sound field is not reproduced accurately; (2) if (N) is too large, computing time increases and solution accuracy decreases. The method beaks down when excitation frequency coincides with the eigenfrequencies — a narrow range of frequencies — of the space formed by the auxiliary surface. As the auxiliary surface is frequently represented by simple surfaces (cylinder, sphere), one can easily calculate the eigenfrequencies and therefore avoid them.

Genomic regions affecting seed shattering and seed dormancy in rice

Non-shattering of the seeds and reduced seed dormancy were selected consciously and unconsciously during the domestication of rice, as in other cereals. Both traits are quantitative and their genetic bases are not fully elucidated, though several genes with relatively large effects have been identified. In the present study, we attempted to detect genomic regions associated with shattering and dormancy using 125 recombinant inbred lines obtained from a cross between cultivated and wild rice strains. A total of 147 markers were mapped on 12 rice chromosomes, and QTL analysis was performed by simple interval mapping and composite interval mapping. For seed shattering, two methods revealed the same four QTLs. On the other hand, for seed dormancy a number of QTLs were estimated by the two methods. Based on the results obtained with the intact and de-hulled seeds, QTLs affecting hull-imposed dormancy and kernel dormancy, respectively, were estimated. Some QTLs detected by simple interval mapping were not significant by composite interval mapping, which reduces the effects of residual variation due to the genetic background. Several chromosomal regions where shattering QTLs and dormancy QTLs are linked with each other were found. This redundancy of QTL associations was explained by ”multifactorial linkages” followed by natural selection favoring these two co-adapted traits. Received: 23 November 1998 / Accepted: 27 August 1999     

Relationships between indices of seed maturity and carrot seed quality

Carrot seeds cvs Chantenay and Amsterdam were harvested on several occasions from crops grown in 1985 and 1986, from the time they had reached or were close to their maximum dry weight and were starting to turn brown. Maximum seed dry weight occurred approximately 40–45 days after flowering (DAF) in both cultivars. Maximum germination (International Seed Testing Association 14-day count) occurred 40 and 55 DAF in cvs Chantenay and Amsterdam, respectively, but the maximum 7-day count and the minimum coefficient of variation of embryo length did not occur until 60 DAF in cv. Chantenay and 55 to 65 DAF in cv. Amsterdam. Percentage germination was negatively and linearly related to seed moisture content, chlorophyll a + b content in the seed coat and seed distortion, measured on a modified tensile-testing machine, the relationships accounting for 77, 71 and 64% of the variance in the 7-day germination count, respectively. The corresponding values for the 14-day count were 63, 61 and 50%. A simple field test for monitoring seed maturity is proposed.