Seed production and seed quality in a calcareous grassland in elevated CO2

In diverse plant communities the relative contribution of species to community biomass may change considerably in response to elevated CO₂. Along with species‐specific biomass responses, reproduction is likely to change as well with increasing CO₂ and might further accelerate shifts in species composition. Here, we ask if, after 5 years of CO₂ exposure, seed production and seed quality in natural nutrient‐poor calcareous grassland are affected by elevated CO₂ (650 μ L L^?1 vs 360 μ L L^?1) and how this might affect long‐term community dynamics. The effect of elevated CO₂ on the number of flowering shoots (+ 24%, P < 0.01) and seeds (+ 29%, P = 0.06) at the community level was similar to above ground biomass responses in this year, suggesting that the overall allocation to sexual reproduction remained unchanged. Compared among functional groups of species we found a 42% increase in seed number (P < 0.01) of graminoids, a 33% increase (P = 0.07) in forbs, and no significant change in legumes (? 38%, n.s.) under elevated CO₂. Large responses particularly of two graminoid species and smaller responses of many forb species summed up to the significant or marginally significant increase in seed number of graminoids and forbs, respectively. In several species the increase in seed number resulted both from an increase in flowering shoots and an increase in inflorescence size. In most species, seeds tended to be heavier (+ 12%, P < 0.01), and N‐concentration of seeds was significantly reduced in eight out of 13 species. The fraction of germinating seeds did not differ between seeds produced in ambient and elevated CO₂, but time to germination was significantly shortened in two species and prolonged in one species when seeds had been produced in elevated CO₂. Results suggest that species specific increases in seed number and changes in seed quality will exert substantial cumulative effects on community composition in the long run.     

Temperature influence on the reproduction of Podisus nigrispinus, a predator of the noctuid larva Alabama argillacea

The influence of temperature on thereproduction and longevity of Podisusnigrispinus (Dallas) (Heteroptera:Pentatomidae) fed with Alabamaargillacea (Hübner) (Lepidoptera:Noctuidae) larvae was studied. This predatorwas reared at constant temperatures of 20, 23,25, 28, 30 and 33 ± 0.2 °C, all atrelative humidity of 60 ± 10%, and aphotoperiod of L:D 14:10. Fecundity of P.nigrispinus at the various temperatures rangedfrom 401.2 (33 °C) to 841.3 (28 °C) eggs/female. The preoviposition,oviposition peak, and declining ovipositionperiods of P. nigrispinus were affectedby temperature [preoviposition period: 4.0 (33 °C) to 13.2 (20 °C) days;duration of oviposition peak period: 9.0 (33 °C) to 33.0 (20 °C) days; andduration of declining oviposition period: 16.0(33 °C) to 46.0 (20 °C) days].Longevity of females and males of P.nigrispinus ranged from 28.4 (33 °C) to88.6 (20 °C) days, and from 42.7 (33 °C); to 114.3 (20 °C) days,respectively. These data are useful in relationto the development of population dynamicsmodels to underpin programmes of biologicalcontrol.     

Growth and reproduction of horse mackerel,Trachurus trachurus (carangidae)

There is a broad knowledge of the growth andreproduction of Trachurus trachurus,although important gaps still exist. Horsemackerel are a long-lived species, reaching upto 40 years of age. They have isometric growth,although the alometric parameter b mayvary throughout the year and in relation tolatitude. Growth to age 3 is rapid compared toslower growth later in life. Phenomena ofdensity dependent growth have been observed inthe northeast Atlantic. Horse mackerel are anasynchronous species. The following stages ofatresia have been validated in horse mackerel:alpha, beta, and delta. The transition infemales from the spawning state to postspawning is very fast. The spawning fraction inhorse mackerel is estimated to be between 8.3%and 20.9%. Horse mackerel have a long spawningseason (up to 8 months), which varies accordingto geography. Length at first maturity isbetween 16 and 25 cm, most commonly around21 cm. Males mature at a slightly smallerlength than females. The age at first maturityfor females has been estimated to range from 2to 4 years, depending on the geography. Batchfecundity has been estimated to range between172–209 oocytes per gram-female-weight. Femalespawning lasts between 65 and 94 days. Anindividual female can release from 5 to 16batches during the spawning period. Theestimated potential annual relative fecundityranges from 1040 to 3280 oocytes pergram-female-weight.     

BMPR-IB和BMP15基因作为小尾寒羊多胎性能候选基因的研究

以控制BooroolaMerino羊多胎性能的BMPR IB基因 ,以及影响Invedale和Hanna羊排卵数的BMP15基因作为候选基因 ,从分子水平上对小尾寒羊的多胎机制进行研究 ,分析突变位点的特性 ,并通过大规模的群体检测统计推断其遗传效应。实验结果表明 :多胎品种小尾寒羊在BMPR IB基因的相应位置上发生了与BooroolaMerino羊相同的突变 (A74 6G) ,该基因的BB基因型在小尾寒羊群体内为优势基因型 ,且小尾寒羊初产和经产母羊的BB基因型比 ++基因型分别多产 0 97羔 (P <0 0 5 )和 1 5羔 (P <0 0 1) ,推测BMPR IB基因与控制小尾寒羊多胎性能的主效基因存在紧密的遗传连锁。而BMP15基因在小尾寒羊中不存在V31D或Q2 3Ter突变 ,说明小尾寒羊的多胎遗传机制与Romney羊不同 ,因此排除了BMP15突变影响小尾寒羊排卵数的可能性。     

四种食料植物对八字地老虎生长发育和繁殖的影响

研究了油菜、甜菜、白菜和莴苣 4种食料植物对八字地老虎Agrotisc nigrumLinnaeus幼虫发育历期、蛹期、蛹重、成虫寿命和产卵量的影响。幼虫取食油菜时发育历期最短 (1 5 4d) ,蛹最重 (2 0 3 5mg) ,产卵量最多 (3 89 5粒 ) ,甜菜次之。幼虫取食莴苣时发育历期最长 ,蛹最轻 (1 3 6 1mg) ,产卵量最少(1 44 7粒 )。 4种食料植物对寄主的蛹期和成虫的寿命没有显著的影响     

南昌地区灰飞虱的生活史、繁殖和越冬生物学特性

为了探明灰飞虱Laodelphax striatellus (Fallén)在南昌地区的生物学特性, 本研究在实验室和自然条件下系统调查了该虫的年生活史, 温度对其生长发育、 繁殖、 性比及翅型分化的影响, 及其越冬生物学。结果表明, 灰飞虱在南昌一年发生4~7代。在18~32℃, 卵的发育历期随温度升高逐渐缩短。若虫的发育历期在18~28℃随温度升高逐渐缩短, 但若虫的发育历期在30和32℃时显著长于28℃的发育历期（P=0.000﹤0.05）。越冬个体的若虫期为143~187 d。卵和若虫的发育起点温度分别为10.17℃和7.51℃。在室外, 7月中旬高温下孵化的第4代若虫的发育历期也明显延长, 显示了高温诱导的夏季休眠现象。在18~28℃, 产卵前期随温度升高而逐渐缩短, 当温度上升到30℃时, 其产卵前期比26和28℃下有所延长。产卵期在22℃最长, 30℃下最短。成虫在20~24℃下的寿命最长。在28℃下, 平均每雌产若虫量最大。不论在室内还是在室外, 雌雄比均接近1∶1。在18~32℃, 羽化的成虫均以长翅型占绝对优势。在自然条件下, 越冬代和第6代羽化的成虫以短翅型占优势, 其他各代仍以长翅型占优势。在自然条件下, 9月中旬孵化的若虫就有少量个体滞育越冬, 10月中旬后孵化的若虫全部进入越冬。越冬若虫的龄期为1-5龄。本研究为该虫发生的预测及有效防控提供基础资料。     

精子功能相关的蛋白质调控受精过程的研究进展

哺乳动物的受精过程涉及到精子一系列的功能活动,如精子在雌性生殖道的运行、精子的超活化与获能、顶体反应以及精卵融合等。在精子经历的这一系列过程中,精子功能相关的蛋白质发挥着不可或缺的作用,这些蛋白分子的正常与否与雄性个体的繁殖力高低密切相关,因此精子功能相关的蛋白质能够作为评定哺乳动物精液受精能力的生物标记。文章主要对哺乳动物精子功能相关的蛋白质进行了综述,以阐述相关蛋白分子对精子运动活力、精子获能、顶体反应、透明带穿入和精卵融合等方面的重要作用以及这些蛋白分子在家畜遗传改良上的潜在应用。     

温度对扶桑绵粉蚧生长发育的影响

【目的】扶桑绵粉蚧Phenacoccus solenopsis Tinsley是近年在我国新发现的一种重要外来入侵害虫,对我国棉花生产具有潜在的巨大威胁。本研究以棉花作为寄主,探索恒温及变温条件对扶桑绵粉蚧生长发育的影响。【方法】在光周期为12L∶12D,RH 70%±5％,在系列恒温及变温（温度波动范围为±1℃）条件下,用棉花饲养扶桑绵粉蚧,观察和分析了不同温度下各龄虫态的发育历期、发育速率、存活率和繁殖力及发育起点温度、有效积温、最适发育温度、极限高温等。【结果】在恒温17~32℃范围内,扶桑绵粉蚧各虫态的发育历期随温度升高而逐渐缩短,当温度达到27℃时发育速率值增幅最大,其中在恒温22~32℃范围内,该虫具有较高的生长发育速率和存活率,且繁殖能力较强,而在恒温37℃条件下,该虫不能完成整个生活史而死亡。在循环变温条件（25~40℃）下,该虫表现出更好的适应性：发育历期更短,速率更快,存活率更高,繁殖力也达到了恒温条件下的平均水平。雌雄虫的发育起点温度分别为9.0℃和8.1℃,而达到成虫时所需有效积温分别为322.6日度和344.8日度。通过拟合发育速率与温度之间的非线性回归关系求出雌雄虫最适发育温度分别为30.5℃和29.9℃,而极限高温分别为36.6℃和35.8℃。【结论】扶桑绵粉蚧适温范围广泛,特别是在变温条件下的适应性非常强。这些结果为预测扶桑绵粉蚧在我国主要棉区的分布提供了依据。     

四种植物酚类物质对舞毒蛾生长发育及繁殖的影响

【目的】为明确植物酚类次生物质对舞毒蛾Lymantria dispar (L.) 的影响,并为应用其防治害虫奠定基础。【方法】本研究选用4种酚酸（水杨酸、丁香酸、绿原酸和水解单宁酸）分别加入人工饲料中饲养舞毒蛾2龄幼虫,调查其对幼虫生长发育及繁殖的影响。【结果】不同酚酸对舞毒蛾的影响差异显著。单宁酸处理第12天时幼虫死亡率达到22.2%,显著高于对照（取食不添加任何酚酸的人工饲料）死亡率（3.3%）（P＜0.01）及其他酚酸处理时的死亡率。到第22天单宁酸及绿原酸使幼虫死亡率迅速上升,至第34天时死亡率达到100%;二者处理的幼虫虫体瘦小,发育历期显著延长,不能正常蜕皮,到4龄期时全部死亡。取食含丁香酸或水杨酸饲料的幼虫可幸存至蛹和成虫,雌性蛹重较对照显著增加,但产卵量和卵受精率均显著降低。其中,取食含丁香酸饲料的成虫产卵量和卵受精率分别比对照减少近90粒和降低约35%,雌性成虫比例下降。【结论】结果说明不同酚酸在害虫体内的积累会对其生长发育及繁殖产生不同程度的影响。     

麻疯树不同种源的结实性差异与初期选择

采用随机完全区组设计对5年生麻疯树Jatropha curcas种源林进行结实性调查。结果表明,不同种源麻疯树单株产种量有不同程度的差异,云南元阳种源最高,达218.96 g,四川盐边种源最低,仅为48.42 g。不同种源麻疯树种子平均含油率也有所不同,广西隆林种源最高,达42.80%,贵州望谟种源最低,为37.23%。单株产种量与种源地纬度、年均气温显著相关,而与种源地无霜期极显著相关,其中与纬度为负相关,与年均气温、无霜期为正相关,说明纬度较低、气温较高和无霜期较长的种源在福建平和县的单株产种量高。而种子平均含油率与各地理气象因子之间没有显著相关性。根据单株产种量和种子平均含油率聚类分析,分别将9个种源分成优、良、中、差4个不同的类别,综合来看,云南东南部和广西西北部可能是麻疯树的优良种源区,该区域内的5个种源,单株产种量达147.43 g,种子平均含油率达41.07%。