真水狼蛛胚胎发育过程中形态和主要化学物质含量的变化

采用常规石蜡切片和液体石蜡透明卵壳的方法,系统地观察了真水狼蛛的胚胎早期,体节期,胚胎速转期和幼虫期4个发育阶段的形态特征和发育过程,并测定了胚胎发育过程中卵的内主要化学物质含量的变化,在28度时,真水狼蛛的卵从产卵到孵化共需144小时,其中胚胎早期42小时,体节期33小时,胚胎逆转期27小时,在胚胎逆转期后进入前幼虫期,前幼虫期42小时,真水狼蛛的胚胎逆转现象很明显,表明真水狼蛛的进化程度较高,在胚胎发育过程中,卵的含水量,含脂量和卵重在胎发育24hr后开始下降,卵的蛋白质含量在48小时后也开始下降,含糖量下降不明显。     

真水狼蛛的抗逆力研究

研究不同龄期真水狼蛛的抗逆力,并以3龄幼蛛为对象,研究了温度和食物对抗逆力的影响。结果表明:真水狼蛛的耐旱力很差,在无水的情况下,无论有无食物,均在2d之内死亡。其耐饥力随着龄期的增长而增加;雌蛛的耐饥力大于雄蛛。在23～35℃温度范围内,3龄幼蛛的耐饥力与温度呈明显的负相关关系。喂混合食物时,3龄幼蛛的耐饥力最强。温度和食物对耐旱力的影响不大。     

真水狼蛛纺器的扫描电镜观察

通过室内饲养,获得了不同龄期的真水狼蛛。对其纺器扫描电镜观察表明：真水狼蛛的纺器表面分布许多纺管,纺管的数目随着龄期的增大面增加。１龄幼蛛纺器分化没有完成。因而不能纺丝。雌蛛和雄蛛在纺器的排列位置、形态、纺管类型和纺管数目上都存在较大差异。纺器的形态、结构与纺器纺丝、结网的功能相适宜。     

食物对真水狼蛛发育和繁殖的影响

研究4种食物对真水狼蛛发育和繁殖的影响.结果表明:单喂果蝇时,幼蛛世代存活率最低;喂混合食物时幼蛛历期最短;单喂果蝇时,历期最长.幼蛛腹部体色与所喂食物颜色相近.喂混合食物的幼蛛,其背甲宽度和体重均大于其他3种食物.雌蛛所产卵袋数和产卵总量均以喂混合食物时为最高.多种食物混合喂养,有利于真水狼蛛的个体发育和繁殖.     

真水狼蛛幼蛛各龄期的形态特征和生长发育

幼蛛在蜘蛛的种群中占有很大比例。通过室内饲养。获得了不同龄期的真水狼蛛幼蛛。其体重、体长、背甲宽、步足长、眼域宽以及中斑下的条形纵斑长度都随着龄期的增大而增加。背甲宽和中斑下的条形斑纹长度可用来判断真水幼蛛的龄期。雌蛛的取食量大于雄蛛,高龄幼蛛大于低龄幼蛛。幼蛛在蜕皮时不取食,蜕皮后,取食量明显增加。     

真水狼蛛染色体组型分析

蜘蛛染色体的研究是对传统蜘蛛分类方法的验证和补充。以处于囊胚期到体节期之间的蜘蛛胚胎细胞为材料,经秋水仙素处理,低渗、固定、制片及染色,对真水狼蛛的体细胞染色体进行了初步观察。结果表明:真水狼蛛的染色体数为雄性2n=26,雌性2n=28,性别决定机制为X_1X_2O。C-带分析表明;所有染色体均为端着粒染色体,端部有特异性染色质存在。     

真水狼蛛的生物学和田间种群动态研究

真水狼蛛在湖北武汉1a发生3个不完整的世代,以第2代历期最短,第3代(越冬代)历期最长。主要以亚成蛛越冬。雌、雄均可多次交配。真水狼蛛1生最多可产4个卵袋,平均2.8个,含卵量较大(平均90粒)。雌蛛有较强的护卵、护幼习性。卵的孵化率较高,平均孵化率为91.36％。真水狼蛛共蜕皮6次,有7个龄期。性比各个世代均为雌蛛多于雄蛛。真水狼蛛捕食叶蝉、飞虱等多种水稻害虫,捕食量与龄期、蜕皮和性别有关。真水狼蛛在6月5日左右开始由田埂向稻田内迁移,1a有2个发生高蜂,分析了影响真水狼蛛种群动态因素。     

温度对真水狼蛛发育和繁殖的影响

报道了具水狼蛛发育和繁殖的影响,２０～３２℃恒温条件,随着温度的升高历期变句。真永恒蜂在武泽地区一可发生２～３代。幼蛛发育到成熟所蠕蜕皮次数与温度有关,在各种温度下,均以蜕皮６次的个体最多,２７℃恒温条件下,产卵率最高,化率最高;３０』下单此产卵量最大。每蛛携带幼蛛的时间随温度和升高的而缩短。根据真水蛛蛛在６种恒温下的的幼蛛存活率,雌蛛产卵率,产量量和孵化率组了真水狼蛛在不同温度条件下的实验种各增     

真水狼蛛对褐飞虱捕食作用的初步研究

应用二次正交旋转组合的设计方法,研究了在不同的天敌密度、害虫密度、温度和光照时间的动态系统中,真水狼蛛对稻田主要害虫褐飞虱的捕食作用。得出其控制作用的数学模型为:y=27.4087 3.1667 x_1 6.8333 x_2-1.1667 x_3 0.5000 x_4-0.4258 x_1~2-0.9258 x_2~2-3.1758 x_3~2 .2500 x_1x_2 0.5000 x_1x3-1.5000 x_3x_4通过模型的主效应分析.得出了各环境因子对天敌捕食作用的影响。真水狼蛛对褐飞虱的日捕食量为19.372头。     

Effect of temperature and photoperiod on diapause development in a Douglas fir seed chalcid, Megastigmus spermotrophus

Douglas fir seeds infested by diapausing larvae of a chalcid, Megastigmus spermotrophus, were transferred under different temperature and photoperiod regimes at various dates during autumn and winter. Both winter diapause and prolonged diapause were compared to the diapause patterns observed in control lots kept under natural conditions. The results showed that exposure to low temperatures in autumn and winter is required for the completion of diapause development. Median adult emergence dates and the date of transfer of larvae to 20°C were negatively correlated. The frequency of prolonged diapause of larvae transferred to 20°C decreased significantly after November. When larvae were submitted to different constant temperatures, the longer the daylength, the higher and faster the reactivation. These results suggest that chalcid larvae can perceive daylength through the seed coat. This phenomenon is probably related to the fact that most of the infested seeds falling in autumn are usually covered by a layer of leaf litter during the winter. Received: 14 June 1996 / Accepted: 24 February 1997     

温度和盐度对中华多刺鱼胚胎发育过程的影响

2006年3-5月,在北京怀柔水库入库河流怀九河的西四渡河河段,采集性成熟的中华多刺鱼(Pungitius sinensis),人工干法授精获取受精卵,观察并记录受精卵的胚胎发育历程;设置温度和盐度梯度,观察温度和盐度对中华多刺鱼胚胎发育过程的影响。结果表明:北京地区的中华多刺鱼胚胎发育的起始温度(生物学零度)为4.7℃,适宜的发育水温为14.0℃-16.0℃,与中华多刺鱼繁殖盛期(4月中下旬)自然水体的水温相近;平均水温14.0℃时,中华多刺鱼完成胚胎发育约需183h;水温升至22.5℃时,胚胎的孵化率仅为22.2%;水温升至25.0℃时,受精卵不能孵化,此温度应是中华多刺鱼胚胎发育温度的上限。实验表明,北京地区中华多刺鱼的胚胎对盐度的耐受力较为有限,在与自然水体相同的盐度下(0‰)其孵化率接近100%;随着盐度的升高,孵化率降低,8‰盐度时,仅有56%的受精卵孵化;至20‰时,受精卵全部死亡,此盐度应为中华多刺鱼胚胎发育的盐度上限。     

光温条件对短光低温不育水稻育性转换的影响

短光低温不育水稻是一类与长光高温不育水稻育性转换特性相反的新种质,通过对分期播种材料自然条件下的育性及人工短光处理后的育性比较分析表明,宜DIS的光敏期为第一苞分化期至第二次枝梗原基和小穗原基分化期（幼穗分化I－III期）,在常温下光敏期的短日处理可使育性趋于不育,但在高温下光敏期短日不育效应被削弱,宜DIS的花粉育性在高,低温作用下育性的均出现下降,根据高,低温影响育性的资料分析得到的敏感期基本一致,即花粉母细胞形成期至花粉内容物充实期（幼穗分化V－Ⅶ期）。     

不同温度、土壤含水量及日光照时数对棉露尾甲虫(Haptoncus luteolus (Erichson))生长发育的影响

在5,10,15,20,30℃等5种温度、10%,20%,30%等3种土壤含水量和8,12,16h等3种日光照时数共45个处理组合条件下,以丝瓜花作为饲料研究了3个因素对棉露尾甲生长发育的联合作用。结果表明:适合于卵生长发育的处理组合为25～35℃、10～15%和12～16h,其中最佳处理组合为30℃、10%和12h,在此组合条件下,卵发育历期为0.8d,孵化率为93.3%;适合于幼虫及蛹生长发育的处理组合为:25～30℃、10～15%和12～16h,其中最佳处理组合分别为30℃、10%、12h和30℃、10%、8h,在此组合条件下,幼虫历期、存活率和蛹历期、羽化率分别为5.0d、85.7%和2.2d、83.3%。在三元二次回归模型中,卵、幼虫、蛹和整个未成熟期(卵至蛹的历期)发育进度最快时的处理组合分别为27.5℃、10%、8h,30℃、20%、12h,32.5℃、10%、16h和30℃、10%、16h;此时理论最短历期分别为0.8、4.4、1.4d和7.3d。     

Effect of carbon dioxide and relative humidity on self incompatibility in cauliflower,Brassica oleracea

Summary The events of the progamic phase of fertilization have been monitored by in vitro experiments in self compatible (SC), partial self-incompatible (PSI) and self incompatible (SI) lines. The duration of the progamic phase is about 30 h. Treatment with low concentrations of CO₂ (3 to 5%) at high relative humidity (rH, 100%) had the following effects: pollen quality, which declines normally during flower ageing, was prematurely reduced; pollen adhesion and germination, both low in SI matings, were increased; the stigma callose response in SI matings was reduced to the low level of SC matings; and the number of pollen tubes in the style after SI matings significantly increased. CO₂ concentrations of 4 to 6% applied for 8, 16 or 24 h at 100% rH proved to be the most effective treatment for blocking the SI response in cauliflower.     

The influence of relative humidity on Beauveria bassiana infectivity and replication in the chinch bug,Blissus leucopterus

Beauveria bassiana conidia were bioassayed for pathogenicity against adult chinch bugs, Blissus leucopterus leucopterus, at varying percent relative humidities (RH). The conidia were found to be invasive and pathogenic at all humidities tested. Normal fungal replication and conidiogenesis, however, occurred only on the hosts incubated at the 75% or higher RH levels.     

Effects of incubation temperature on the energetics of embryonic development and hatchling morphology in the Brisbane river turtle Emydura signata

Incubation temperature and the amount of water taken up by eggs from the substrate during incubation affects hatchling size and morphology in many oviparous reptiles. The Brisbane river turtle Emydura signata lays hard-shelled eggs and hatchling mass was unaffected by the amount of water gained or lost during incubation. Constant temperature incubation of eggs at 24 °C, 26 °C, 28 °C and 31 °C had no effect on hatchling mass, yolk-free hatchling mass, residual yolk mass, carapace length, carapace width, plastron length or plastron width. However, hatchlings incubated at 26 °C and 28 °C had wider heads than hatchlings incubated at 24 °C and 31 °C. Incubation period varied inversely with incubation temperature, while the rate of increase in oxygen consumption during the first part of incubation and the peak rate of oxygen consumption varied directly with incubation temperature. The total amount of oxygen consumed during development and hatchling production cost was significantly greater at 24 °C than at 26 °C, 28 °C and 31 °C. Hatchling mass and dimensions and total embryonic energy expenditure was directly proportional to initial egg mass. Accepted: 18 March 1998     

Effects of relative humidity and temperature conditions on pollen fluorochromatic reaction of Rosmarinus officinalis L. (Lamiaceae)

Summary. Mediterranean ecosystems are characterized by seasonal and annual fluctuations in humidity and temperature which are considered limiting factors for plant growth and might have played a key role in the selection of species that compose the present vegetation. After anther release, pollen is generally exposed to various changes of temperature and humidity conditions, therefore its viability and consequently successful fruit set are strongly affected by these environmental parameters. The aim of this research was to study the effect of different combinations of humidity and temperature on pollen membrane integrity of Rosmarinus officinalis L. in order to investigate possible relations between pollen features and climatic conditions during flowering. This species is an evergreen perennial shrub, occurring among the sclerophyllous vegetation of Mediterranean maquis. In many areas of Southern Italy, it shows a flowering period starting from the beginning of winter and spreading throughout spring months. The analysis of data showed that duration of pollen viability of R. officinalis is enhanced by the co-occurrence of low temperature and high humidity. Moreover, these conditions are able to newly raise the viability of pollen kept at higher temperatures and lower humidity. These observations indicate that reactivation of the pollen membrane depends on low temperature apart from high humidity. Therefore “vernalization” of rosemary pollen enhances its viability, supporting that pollen behavior is adapted to winter condition and allows flowering in winter and early spring. Correspondence and reprints: Laboratorio di Botanica ed Ecologia Riproduttiva, Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, Università degli Studi di Napoli Federico II, Via Università 100, 80055 Portici, Naples, Italy.     

Effect of photoperiod and light intensity on in vitro propagation of Alocasia amazonica

Plantlets of Alocasia amazonica regenerated under a photon flux density (PFD) of 15 or 30 μmol m⁻² s⁻¹ showed better growth and development than those grown under higher PFDs. While chlorophyll a and chlorophyll b decreased, the number of stomata increased with increasing PFD. Photoperiods also affected plantlet growth and stomatal development. Highest growth was observed for the short photoperiod (8/16 h) and for equinoctial (12/12 h) light and dark periods. Very few stomata developed in the leaves of plantlets grown under a short photoperiod (8/16 h) and the number of stomata increased with increasing light period. In conclusion, both light intensity and photoperiod independently affect growth of A. amazonica and development of stomata, depending on the intensity and duration of light treatment.