模拟增温和丛枝菌根对门源草原毛虫幼虫生长发育的影响

采用开顶式生长室(Open top chamber, OTC)模拟增温和苯菌灵抑制丛枝菌根研究上述两种因素综合作用下门源草原毛虫幼虫的生长速率、蛹化时间和蛹重。结果表明,增温和丛枝菌根抑制及其交互作用均对门源草原毛虫幼虫生长速率产生了显著影响。相比对照组而言,增温使该指标升高了34%。丛枝菌根抑制未对上述指标产生显著影响。增温和丛枝菌根抑制的交互作用使门源草原毛虫幼虫生长速率较对照组升高了16%,而较增温组降低了13%。增温处理下雌、雄幼虫的蛹化时间分别为204、218 d,而不增温处理下分别为212、223 d。增温使得雌、雄幼虫的蛹化时间较不增温处理分别提前了2%和4%。增温和不增温处理下的雌、雄虫蛹化时间差分别为15、12 d。增温将上述时间差扩大了25%。此外,增温及其与丛枝菌根抑制的交互作用对门源草原毛虫雌虫蛹重的影响显著,而对于雄虫的蛹重来说,仅增温处理的影响显著。增温和增温丛枝菌根抑制处理,使得雌蛹重较对照组增大了22%和8%。增温使雄蛹重增大了18%。首次研究了增温和丛枝菌根对植食性昆虫的综合影响。     

光周期和温度对枯叶蛱蝶幼虫生长发育的影响

在人工气候箱中研究不同光周期和温度条件下枯叶蛱蝶Kallima inachus Doubleday幼虫的生长发育情况。结果表明,20℃时,光周期对枯叶蛱蝶幼虫发育历期影响明显,25℃和30℃时无明显影响。20,25和30℃,12.5~14h光照下,幼虫发育历期分别为31.7~36.0,26.3~27.4和21.0~21.5d,最长和最短历期分别相差4.3,1.1和0.5d。随着温度升高,在相同光照下,幼虫发育历期缩短。20,25和30℃12.5~14h光照下幼虫存活率分别为80%~92%、75%~95%和55%~85%,随温度上升,不同光周期下幼虫存活率差异加大。30℃时大部分光周期下存活率较低,已对幼虫生长发育不利,人工养殖时温度不宜超过30℃。     

两种温度下异长足漠甲(鞘翅目:长足漠甲族)幼期生长发育比较

本研究首次报道温度对异长足漠甲Adesima anomala dejeani Gebl生长发育的影响。异长足漠甲的整个变态过程饲养使用矿泉水瓶法,并优化了此方法,避免过度失水,进行加水并同时观察。随着温度的升高,发育历期缩短,30℃饲养条件下异长足漠甲的总发育历期为117.4 d,33℃的总发育历期为90.99 d;2龄期、5龄期幼虫的头壳长和宽,前胸长和宽,体长,在33℃饲养条件下显著高于30℃;7龄期幼虫的头壳长和宽,前胸宽,体长,在33℃饲养条件下显著高于30℃;5龄期幼虫,温度30℃时的体重为(0.0634±0.021)g,33℃时的体重为(0.0906±0.0313)g,差异显著;6龄期幼虫,蛹期、孵化成虫在温度30℃时存活率高于33℃。     

温度对以白茶为寄主的米缟螟生长发育的影响

为探明温度对以白茶为寄主植物的产虫茶昆虫米缟螟生长发育的影响,分别设置5个温度条件(31、28、25、22、19℃),研究温度对米缟螟各虫态平均发育历期、发育速率和存活率的影响,计算各虫态发育起点温度和有效积温.结果表明:温度对米缟螟各虫态平均发育历期影响显著,除卵的发育历期随温度的升高而缩短外,幼虫、蛹及未成熟期的发育历期均在25℃达到最小值,分别为(249.53±23.83)d、(12.94±1.27)d和(273.00±24.19)d;除蛹外米缟螟各虫态发育速率与温度呈极显著相关,其中卵的发育速率与温度呈线性相关,幼虫、蛹和未成熟期则呈抛物线相关;温度显著影响各虫态存活率,卵、幼虫、蛹及未成熟期各虫态存活率均在25℃最高,分别为94.0％、73.8％、91.3％和63.4％,22和19℃次之,31℃最低;幼虫及蛹存活率在31℃均为0,表明米缟螟不耐高温;卵、幼虫、蛹及未成熟期的发育起点温度分别为13.21、17.12、14.76和16.47℃,有效积温分别为117.94、870.88、149.70和1442.75日·度.研究结果与米缟螟在贵州息烽地区一年发生2至3代的事实大致相符.     

不同温度对三叶虫萤卵孵化和初孵幼虫发育的影响

本文研究了三叶虫萤Emeia pseudosauteri在不同恒温设置和室内变温条件下卵孵化率和初孵幼虫存活率,并通过直接最优法和直线回归法计算出了三叶虫萤卵的发育起点温度和有效积温。结果表明:12~30℃恒温条件下,卵的孵化率随着温度升高显著下降(P<0.05),且均低于室内变温条件(P<0.05)下的孵化率;初孵幼虫在恒温15℃下的存活率最高,为73.13%;低于12℃和高于30℃恒温中初孵幼虫均无法存活;在恒温条件12~30℃下,卵的发育历期随温度升高而缩短,其中恒温12℃下最长,发育历期为42.96 d(n=3),恒温30℃下最短,发育历期仅12.75 d(n=3)。通过直接最优法计算出三叶虫萤卵的发育起点温度为3.52℃,有效积温分别为382.20 d·℃。上述结果为三叶虫萤的人工繁育提供了参考。     

幼虫期短时高温暴露对二点委夜蛾存活和繁殖的影响

【目的】随着全球气候变暖,夏季短时极端高温发生的频率逐渐增加。本研究旨在探明二点委夜蛾Athetis lepigone幼虫期对高温的适应性。【方法】将二点委夜蛾不同日龄(1,6,12和18日龄)幼虫在不同高温(35,38和41℃)条件下暴露不同时间(0.5,1,2,4和6 h)后转移至适温(26℃)继续饲养,观察短时高温对其存活率、发育历期、化蛹率、羽化率、雌虫寿命、单雌产卵量及次代卵孵化率的影响。【结果】幼虫期短时高温暴露的温度和时间对二点委夜蛾幼虫的存活率和发育历期有显著影响,而对化蛹率、成虫羽化率、雌虫寿命、单雌产卵量以及次代卵孵化率影响不显著。随着温度的升高和处理时间的延长,幼虫存活率逐渐降低,发育历期逐渐延长。其中,18日龄的幼虫最为敏感,38℃和41℃暴露6 h后存活率分别为58.3%和17.7%,显著低于对照,发育历期分别为25.5 d和29.2 d,较对照显著延长。【结论】幼虫期经历短时高温暴露仅对幼虫的存活和发育历期有影响,而对后续蛹和成虫的生长发育及成虫繁殖力没有影响。     

温度对亚洲玉米螟生长发育、繁殖和求偶行为的影响

本文将亚洲玉米螟Ostrinia furnacalis(Guenée)初孵幼虫分别置于16℃、22℃、25℃、28℃、35℃的恒温培养箱,研究温度对其生长发育、繁殖和求偶行为的影响。结果表明,16℃下亚洲玉米螟幼虫仅有2头化蛹,且蛹不羽化,发育停滞。随着温度的升高,幼虫历期逐渐缩短,发育速率与温度呈现正相关。在22℃-25℃范围内,蛹历期和成虫寿命随着温度的升高而延长,而在25℃-35℃范围内时,蛹历期和成虫寿命随着温度的升高而缩短。幼虫存活率在28℃时最高,达57.00%。羽化率、卵孵化率、蛹重、雌雄性比和产卵量均在25℃时最高,并随着温度的上升先上升后下降。在28℃时,雌虫求偶百分率在6个暗期均最高,在第2、3、4个暗期最高达100%。其次是在25℃时,雌虫求偶百分率仅在第4个暗期达到100%。在22℃、25℃、28℃时,雌虫最长求偶持续时间均出现在第3个暗期,分别为4.46 h、4.78 h和5.28 h。当温度升高至35℃时,雌虫求偶高峰期和最高求偶持续时间比在22℃时提前1-2个暗期。     

温度对外来入侵生物番茄潜叶蛾生长发育的影响研究

番茄潜叶蛾Tuta absoluta目前已成为全世界茄科作物的重要害虫之一,尤其对番茄可以造成毁灭性的危害。本研究针对重大外来入侵生物番茄潜叶蛾,研究温度对其生物学特性的影响,为综合防控措施的制定提供科学理论依据。本研究在19℃、23℃、27℃、30℃、33℃、35℃恒温条件下,对番茄潜叶蛾的生物学特性进行了研究。结果表明,温度对番茄潜叶蛾各虫态发育均有显著影响。19～33℃,随着温度的升高,卵的发育历期从6.20 d缩短至2.10 d, 35℃下卵期为2.90 d; 19～30℃,除了4龄幼虫,其他各龄期幼虫和蛹的发育历期均随温度的升高而缩短,1龄幼虫从7.20 d缩短至3.00 d, 2龄幼虫从6.00 d缩短至3.25 d, 3龄幼虫从5.80 d缩短至3.25 d,蛹从9.80 d缩短至4.00 d; 4龄幼虫在19℃下发育历期最长(7 d),27℃下最短(3 d)。23℃卵期、2龄幼虫、3龄幼虫及蛹的存活率均最高,分别为98%、72%、72%和71%,而1龄幼虫在19℃条件下存活率最高,4龄幼虫在27℃条件下存活率相对较高,33℃和35℃时,幼虫无法存活。在23℃条件下,番茄...     

温湿度和食物对暗黑鳃金龟幼虫存活及生长发育的影响

【目的】明确重要生态因素对暗黑鳃金龟Holotrichia parallela幼虫种群的影响,从而为预测预报其发生提供理论依据。【方法】在室内采用自动控制温度、人工控制湿度的方法,观察温度、湿度和食物对暗黑鳃金龟幼虫存活率及发育历期的影响。【结果】结果表明,20~28℃适宜暗黑鳃金龟1-2龄幼虫的存活,其中24℃时存活率最高,达到74.9%±3.1%;12℃时发育历期最长,32℃时发育历期最短,20℃和24℃下发育历期适中。土壤含水量为7%~19%时暗黑鳃金龟1-2龄幼虫均能存活;其中在7%和19%时,幼虫存活率低于50%,在25%时幼虫全部死亡;在土壤含水量为16%时存活率最高,达到76.4%±2.5%。在供试的6种食物(小麦根、玉米根、棉花根、花生根、大豆根和马铃薯块)中,喂饲花生根的暗黑鳃金龟幼虫存活率最高,达到68.7%±3.2%。取食不同食物的幼虫发育历期差异显著,其中取食花生根的暗黑鳃金龟幼虫期最短,整个幼虫期仅为259 d(3龄幼虫期为227 d);而取食棉花根的幼虫期最长,整个幼虫期为346 d(3龄幼虫期为303 d)。【结论】温度、土壤含水量和食物对暗黑鳃金龟幼虫的存活和生长发育均具有显著影响;在幼虫期调控温湿度及改变其寄主植物结构可有效控制其发生危害。     

温度对产虫茶昆虫紫斑谷螟生长发育的影响

为探明温度对贵州主要产虫茶昆虫紫斑谷螟Pyralis farinalis (Linnaeus)生长发育的影响, 本研究以白茶Litsea coreana为寄主植物, 分别设置5个恒温（19, 22, 25, 28和31℃）条件, 研究温度对紫斑谷螟卵、 幼虫、 蛹和未成熟期平均发育历期、 发育速率和存活率的影响, 计算各虫态发育起点温度和有效积温。 结果表明： 温度对紫斑谷螟各虫态发育历期、 发育速率和存活率影响显著。 在19 ~ 31℃范围内, 各虫态的平均发育历期均随温度的升高而缩短, 卵期、 幼虫期、 蛹期及未成熟期均在31℃达到最小值, 分别为4.56±0.24, 43.33±1.50, 7.89±0.20和55.78±1.69 d。 紫斑谷螟各虫态发育速率与温度呈二次回归关系, 且极显著相关。 此外, 温度显著影响各虫态存活率, 卵的存活率在28℃时最高, 为93%; 幼虫和蛹的存活率则在25℃最高, 分别为88%和93%; 温度过高或过低均不利于其生长发育。 由直接最优法计算得到紫斑谷螟卵期、 幼虫期、 蛹期及未成熟期的发育起点温度分别为13.30, 15.48, 13.19和14.82℃, 有效积温依次为88.36, 679.51, 159.73和952.04日·度。 这些结果为紫斑谷螟的繁殖提供了基础参考数据, 对指导虫茶生产有实用参考价值。     

Effect of NaCl,water stress or both on gas exchange and growth of wheat

Responses of wheat (Triticum aestivum L.) to various concentrations of NaCl and levels of drought were followed. With the rise of NaCl or drought, or NaCl and drought together, growth was retarded. The water content of shoots and roots was mostly unchanged. The chlorophyll and carotenoid contents were increased in plants subjected to salinity or drought or both. Only high salinity level induced a considerable decrease in net photosynthetic rate (P_N) and dark respiration rate (R_D). P_N and R_D were decreased with the decrease of soil moisture content. The content of Na⁺ in the shoots and roots of wheat plants increased with increasing salinity or decreasing soil moisture content or both treatments. Considerable variations in the content of K⁺, Ca²⁺ or Mg²⁺ were induced by the NaCl, drought or both treatments.     

不同非生物胁迫对麻疯树幼苗光合速率等生理指标的影响

对麻疯树(Jatropha curcas L.)幼苗在不同非生物胁迫下的净光合速率(Pn)和蒸腾速率(Tr)等生理指标的变化进行了研究。结果表明,在缺磷处理中,麻疯树叶片Pn保持在对照的90%左右,气孔导度(Gs)和胞间CO2浓度(Ci)在处理2 d后显著增加,Gs上升20%～40%,Ci升高4%～16%,Tr变化不大;处理17 d时,麻疯树的P含量下降55%～85%,而干重只下降3%。缺氮处理9 d时麻疯树叶片的Pn下降到最低,之后维持在对照的64%左右,Gs在处理2～7 d显著高出对照15%～57%,处理9～16 d恢复到对照水平,Ci从第2天开始上升,高出对照4%～24%,Tr变化不大;处理17 d时组织中N含量显著下降47%～78%,植株干重下降23%。盐胁迫处理5 d后,麻疯树叶片Pn降低到对照的54%,之后维持在对照的48%左右,Gs、Ci和Tr与Pn的变化一致,均呈下降趋势;处理17 d,叶柄和茎中P含量增加37%～54%,组织中K+/Na+下降87%～96%,植株干重下降18%。干旱胁迫处理6 d,叶片Pn快速下降至29%,Gs、Ci和Tr与Pn整体变化趋势一致;处理第7天,叶片细胞膜透性增加67%,停止浇水17 d后植株干重下降55%,同时叶片卷曲下垂,老叶脱落。麻疯树植株Pn在缺磷胁迫过程中最早达到相对稳定状态,其次为盐胁迫和缺氮胁迫。这说明麻疯树植株对缺磷环境具有良好的适应性,而对缺氮环境适应性相对较差;耐盐类型可能属于逃避盐害中的聚盐植物,适应干旱环境的机制属于御旱性类型。     

Assessment of Genotypic Variation in Salt Tolerance of early CIMMYT Hexaploid Wheat Germplasm Using Photosynthetic Capacity and Water Relations as Selection Criteria

Twenty-five genotypes of early CIMMYT hexaploid wheat were screened for salt tolerance in a glasshouse experiment using photosynthetic capacity and water relation parameters as selection criteria. Under salt stress (150 mM NaCl) the genotypes Frontana, Norin-10, Mayo-54, Noreste-66, and Yaktana-54 excelled all other lines in shoot dry mass, and Na(20)TPP, Penjamo-62, Inia-66, Frontana, Siete Cerros, and Jaral-66 in grain yield per plant in both absolute and relative (percent of control) terms. Although net photosynthetic rate (P _N) declined in all genotypes due to salt stress, it was not helpful in discriminating among genotypes according to salt tolerance. Similarly, no positive relationships of salt tolerance of the genotypes with stomatal conductance, leaf water potential, or turgor pressure were found. Every genotype used its own specific mechanism to tolerate salt stress. However, a large amount of variation in salt tolerance observed in 25 early CIMMYT wheat genotypes can be of considerable practical value for improving salt tolerance in the existing commercial hexaploid wheats. This revised version was published online in August 2006 with corrections to the Cover Date.     

The cryopreservation of Chlorella 1. Interactions of rate of cooling,protective additive and warming rate

The cryoprotective additives glycerol and dimethylsulphoxide were found to be toxic to Chlorella cells at concentrations greater then 2.5% w/v. Polyvinylpyrrolidone, was not damaging up to a concentration of 15% w/v. Chlorella 211/7a had a recovery rate greater than 95% at all rates of cooling studied. With Chlorella 211/8h the survival was lower than 0.1% at all rates examined. The addition of dimethylsulphoxide (5% w/v) to Chlorella 211/8h increased the recovery, particularly at the faster rates of cooling; with polyvinylpyrrolidone (10% w/v) there was an optimum range of cooling rate.Cells of Chlorella 211/7a from the exponential phase of growth were found to be damaged both by a temperature reduction from 25°C to 0°C (thermal shock) and by freezing and thawing. In contrast cells from the stationary phase of growth were resistant to these stresses.Abbreviations DMSO dimethylsulphoxide - HEPES N-2-hydroxyethylpiperazine-N-2-ethansulphonic acid - PVP polyvinylpyrrolidone     

Quantitative studies on the mating system of opium poppy (Papaver somniferum L.)

Summary Nearly 400 individuals at two locations and over a number of years were crossed and subsequently scored for selfing versus outcrossing in eight monohybrid populations of opium poppy (Papaver somniferum). Two different marker loci, petal colour (R/r) and capsule size (B/b) were used to determine the male gametes that had effected fertilizations in F₂ recessives (rr and bb). The estimates of the outcrossing parameter were found to vary with year, location and for the marker locus used ( range: 0.0988–0.3704). Study of two dihybrid crosses involving the two loci simultaneously, further confirmed that outcrossing at the R/r locus was significantly greater than that at the B/b locus. The nature of the outcrossing was, in general, nonrandom. Selfmg predominated in this species; however, there was a high frequency of natural outcrossing for generating variations in P. somniferum.CIMAP publication No. 1086     

Effects of short-term soil flooding on stomata behaviour and leaf gas exchange in barley plants

Exposure of barley plants (Hordeum vulgare L.) to soil flooding for 2 to 24 h reduced the net photosynthetic rate and transpiration rate. Stomatal conductance also decreased in flooded plants. Stomatal closure started within 2 – 6 h and stomata remained closed up to 24 h of treatment.     

授粉方式对铁皮石斛种质座果及种子萌发的影响

为进行铁皮石斛(Dendrobium officinale)的良种选育和种苗生产,对46个铁皮石斛种质进行人工授粉试验,研究了不同授粉方式的授粉成功率、座果率和种子的萌发能力。结果表明,4种授粉方式的授粉成功率明显不同,不同种质间的授粉成功率可达100%,且座果率普遍较高。只有31.3%的种质可以成功自花授粉,且座果率相差较大。同株异花授粉和种质内异株授粉的成功率和座果率均介于上述二者之间。授粉后所得种子的萌发率和萌发速度在4种授粉方式间也呈现与授粉成功率和座果率一致的趋势。这表明在铁皮石斛种质中存在自交不亲和现象,因此以不同产地来源的铁皮石斛种质为亲本进行人工授粉,可大大提高授粉的成功率和座果率,以及后代种子的萌发能力。     

吸湿率和上浮率在枸杞产地检测中的可行性分析

宁夏枸杞（Lycium barbarum）是我国西北地区的一种重要的药食同源的经济作物。为探索一种可行的枸杞产地溯源的方法,对西北地区24个产区枸杞的干果吸湿率和上浮率进行验证。结果表明,枸杞的吸湿率受品种、树龄和果实采收时期的影响,上浮率不受采收季节、干燥方式和树龄的影响。不同地区的枸杞干果吸湿率和上浮率均有差异,产自固原的枸杞干果吸湿率分别为1.47%,显著低于除靖远、玉门、武威外的其他地区（P<0.05）,而产自瓜州地区的枸杞干果吸湿率（2.87%）显著高于其他产区（P<0.05）。产自乌拉特前旗、惠农、靖远、中宁的枸杞干果上浮率分别高达95.56%、95.00%、94.44%、93.29%,显著高于产自共和、格尔木、武威、尉犁、精河、瓜州、阿尔泰地区的（分别为76.67%、73.89%、73.13%、71.67%、67.67%、66.39%、65.00%）（P<0.05）。PCA分析表明,同一产区的枸杞分布集中,产自瓜州、固原和武威等地区的枸杞能与大部分地区区分。因此,吸湿率和上浮率可应用于枸杞的产地检测。     

Direct determination of the effects of genotype and extreme temperature on the transposition of <Emphasis Type="Italic">roo</Emphasis> in long-term mutation accumulation lines of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

Transposable elements (TEs) are mobile repetitive DNA sequences that constitute a structurally dynamic component of genomes. In order to understand the dynamics of TEs it is necessary to have information about the control of transposition and its dependence of environmental factors. After a great deal of previous work on transposition conducted on long-term mutation accumulation (MA) lines of Drosophila melanogaster started in 1987, only roo out of 16 families was found active in this genotype. Here we test the effect of the modification of the genetic background by introducing a Cy chromosome, and the effect of extreme temperature (28°C) on the transposition rate of roo. Thermal stress did not affect the transposition rate, whereas the presence of a Cy chromosome in heterozygosis lowered it. There was an excess of insertions in the X chromosome, with respect to autosomes, and in the proximal and distal regions of chromosome arms that can be interpreted as target site preference. One of the control lines became highly unstable with mean insertion and excision rates of 3.0 × 10⁻³ and 8.5 × 10⁻⁴, respectively. Instability arose spontaneously during generations of mutation accumulation, and can be attributed to “de novo” mutation. Transposition in the unstable line could be directly studied on the progeny of individual males and females, from where we deduced that transposition occurs mainly, if not exclusively, in males, with a rate of 1.125 insertions per gamete. In situ hybridization with an LTR probe showed that most excisions (12 out of 14) were precise. Our data show the prominent role of genotype in transposition control and can explain rapid turnovers in the genome without increasing the number of copies.     

Episodes of unpalatable prey reduce consumption and growth of juvenile praying mantids

Third-instar praying mantids (Tenodera sinensisSaussure: Mantidae) were fed either a sequence of unpalatable milkweed bugs (Oncopeltus fasciatusDallas: Lygaeidae) and palatable fruit flies (Drosophila melanogasterMeigen: Drosophilidae) or a control diet of palatable flies only. Mantids fed a sequence of 3 days of unpalatable bugs and 4 days of palatable flies took, on average, 5 days longer to develop to the fourth instar than the controls, and consequently, their growth rate was less than that of the controls. They ate 10–15 unpalatable bugs in that time, but also, because the stadium was prolonged, they ended up eating as many flies as the faster-growing controls and therefore attained similar biomass. Mantids subjected to episodes of 2 days with unpalatable bugs followed by 4 days of flies had reduced growth rates that were a function of both more time spent in the stadium and less weight gained than the controls. Mantids subjected to episodes of 1 day with unpalatable bugs followed by 4 days of flies did not gain as much weight as the controls but had similar growth rates. Mantids fed unpalatable bugs on Days 1 and 6 and palatable flies on the other days and mantids fed flies for 4 days and then 1 day without food grew at the same rate. In this case, eating unpalatable prey for 2 days of 7 (with 7 days = average stadium duration) slowed weight gain as much as missing food for a day. We conclude that, depending on the sequence, episodes (in this case, 1 or more days) of eating unpalatable prey can reduce the daily rate of consumption sufficiently to have a negative impact on biomass gained, stadium duration, and growth rate.