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1.
走进内蒙     
孙丹辉 《化石》2016,(1):61-65
2015年8月1日,我们每一个人收拾好行囊,整装待发,在邓涛老师带领下踏上了去往内蒙古的征程,拉开了探索灰色生命之旅的序幕. 队伍由两辆车、8人组成,我们早晨7点从中国科学院古脊椎动物与古人类研究所出发,披着清晨的阳光,摆脱城市的拥挤,缓缓地“逃离”了北京城.直到抵达张北之后我们的车子才能像矫健的马儿一样驰骋在广袤的公路上,沿途没有了城市的喧闹,没有了交通的堵塞,伴随我们的只有那一眼望去蓝蓝的天空、随风摆动的小草,以及那迷人的风景,偶尔打开车窗,一股凉爽的清风扑面而来,沁人心脾.经过一路的颠簸,我们在傍晚时刻到达锡林浩特,当地文物保护站的同志为我们安顿好了一切.  相似文献   

2.
孔昭宸 《化石》2007,(3):22-24
巍峨的青藏高原,雄踞于地球之巅,这片既古老而又年轻的大地,以其独特的地理景观,丰富的自然资源和悠久的地域文化,曾召唤着来自不同国度和年龄段的科学工作者致力于以“青藏高原的隆起及其对自然环境和人类活动的影响”为主题的科学研究。他(她)们在这片惊险而又充满神秘色彩的雪域高原的崎岖山路上,留下了其足迹,取得的研究成果,为青藏高原综合研究的主题增添了耐人寻味的古生物学证据。翻开亚洲新生代地质历史,喜马拉雅山的上升被认为是最重要的地质事件。由于这条东西长2400余km,南北宽200~350km的山峦重迭、群峰林立的山系隆起,不仅制约…  相似文献   

3.
昆虫孤雌生殖中中心体的组装和意义   总被引:2,自引:0,他引:2  
中心体是动物细胞主要的微管组织中心(microtubule organizing center, MTOC), 负责组织纺锤体.近年来, 关于昆虫卵母细胞减数分裂后中心体形成的深入研究对阐明昆虫孤雌生殖的过程和机制以及了解孤雌生殖的进化和形成具有重要意义.综述了第一次有丝分裂纺锤体的形成、中心体的装配以及中心体对于昆虫孤雌生殖的意义, 表明昆虫孤雌生殖的普遍模式就是在没有精子提供中心粒的情况下, 卵子通过新形成的中心体进行有丝分裂, 中心体自我组装限制的解除可能是进行孤雌生殖的转折点.  相似文献   

4.
光合作用速率测定是植物光合作用研究的重要基础,沉水植物由于所处生境的特殊性,难以应用在陆生植物光合作用研究中发展起来的速率测定方法.在对水体中二氧化碳的基本特征进行详细描述的基础上,介绍了在沉水植物光合作用研究中广泛应用的电化学方法--pH-stat法和pH-drift法的原理,并给出了应用实例.这两种测定水生植物光合作用的电化学方法所依据的溶液无机碳浓度的变化可以利用Gran滴定法方便地计算出来.  相似文献   

5.
郭建崴 《化石》2016,(1):68-71
今天,当我们谈起进化论的时候,没有人不知道达尔文的鼎鼎大名.没错,正是达尔文根据自己20多年的考察、研究和思考,在1859年出版了影响世界的《物种起源》一书,创立了以自然选择为机制的生物进化理论体系.这个理论就像一盏明灯,照亮了当时那个被《圣经》的教义笼罩得黑沉沉的人类精神世界,使越来越多的人看清了有着更为客观之来龙去脉的世间万物更为真实的面目,同时也给整个科学界和人类的认识领域开启了一个全新的视野.对于生物学这支科学的舰队而言,进化论就象指南针一样,引导着代表各个分支学科的航船向着更远的方向协调前进.当这支舰队已经驶入诸如“人类基因组计划”和“克隆”技术这些现代领域的时候,回顾航迹我们发现,如果没有进化论,这个乘风破浪的远征是无法想象的.  相似文献   

6.
一群雪橇犬在被冰雪覆盖的南极大陆上孤独地生活着,除了必要的觅食,还坚守着早已人去楼空的勘测站,难以想像的175天——这就是电影《南极大冒险》,一个感人至深的故事。南极大陆是令人神往的地方,圣洁的冰雪世界总给人无尽的遐想,一群科学家为了寻找火  相似文献   

7.
在唯物主義的米丘林生物學的基本規律中,關於有機體與他的生活條件的統一這個命題,占據着中心地位。為了支配的目的而了解及掌握有機體的個別的發展及生物的質的改造——物種及變種的界限等,必須對這個命題作多方面的學習,才能達到。因此可見,在講授生物學原理時,使學生對於有機體與他的生活條件的統一的命題,獲得正確的了解,必須予以特別的注意。雖然初看時,這個命題,似乎是很簡單而明白的,然而這種看法往往是不正確的。  相似文献   

8.
每年有大量来自工业、农业、养殖业和城市污水处理厂的废水被排入到水环境中,因此,地球上的水环境面临大量来自生活废水、工农业废水、非法排放的废水及其它废水的污染物质(如抗生素、杀虫剂,除草剂、烃等)的严重挑战,特别是近年来随着集约化养殖的发展,废水污染问题日益突出,并且随着分析手段的进步,能够检测到被排入水环境中的化学污染物质也越来越多,这些化学污染物对水环境中的生物产生有害影响.但是,微生物在污染控制上具有许多重要的作用.因此,本文对微生物在水环境污染物降解中的应用进行了评论.结果表明微生物主要是应用在水产养殖水中,而在其它的水体系(如河、湖、海)的应用较少.  相似文献   

9.
70年前,1882年4月19日,关于生物界演化的唯物学说的创造者,在生物科学中完成了大革命、把生物学奠立在科学基础上的天才的学者查理士·达尔文逝去了。在将近一世纪的期间,先进的生物科学依靠于奠立在达尔史著作基础上的进步的思想,顺利地发展着,获得了日新月异的成就。反动的科学千方百计的企图颠覆达尔文主义,仍然遭受到了失败。  相似文献   

10.
当前,世界上存在着严重的能源危机。据有关专家估计,世界原油如以目前的速度消耗,到二十一世纪中即全部告罄。在这种形势下,各国政府都采取了相应的对策,开发能源作为一个新课题,已十分紧迫地提到科研的日程上。 据调查我国煤和石油的储量不能完全满足未来经济发展的需求,我国也在注意寻找能够代替传统的煤和石油的新能源,如太阳能,风力、地热、生物动力资源……等等。 随着生物工程的飞速发展,对生物量的利用也取得很大进展。从节能与防止环境污染的角度看,利用生物量开发新能源是很有前途的。  相似文献   

11.
Primates tend to prefer specific plant foods, and primate home ranges may contain only a subset of food species present in an area. Thus, primate feeding strategies should be sensitive to the phenology of specific species encountered within the home range in addition to responding to larger scale phenomena such as seasonal changes in rainfall or temperature. We studied three groups of Javan gibbons (Hylobates moloch) in the Gunung Halimun‐Salak National Park, Indonesia from April 2008 to March 2009 and used general linear mixed models (GLMM) and a model selection procedure to investigate the effects of variation in fruit and flower availability on gibbon behavior. Preferred foods were defined as foods that are overselected relative to their abundance, while important food species were those that comprised >5% of feeding time. All important species were also preferred. Season and measurements of flower and fruit availability affected fruit‐feeding time, daily path lengths (DPL), and dietary breadth. Models that included the availability of preferred foods as independent variables generally showed better explanatory power than models that used overall fruit or flower availability. For one group, fruit and preferred fruit abundance had the strongest effects on diets and DPL in the models selected, while another group was more responsive to changes in flower availability. Temporal variation in plant part consumption was not correlated in neighboring groups. Our results suggest that fine‐scale local factors are important determinants of gibbon foraging strategies. Am. J. Primatol. 74:1154‐1167, 2012. © 2012 Wiley Periodicals, Inc.  相似文献   

12.
南方高丛蓝浆果‘南月’实生后代果实特性的变异分析   总被引:4,自引:0,他引:4  
对南方高丛蓝浆果(Vaccinium corymbosum hybrids)品种‘南月’(‘Southmoon’)实生后代的单果质量、果实横径、可溶性固形物含量、单果种子数、果色、口感以及蒂痕类型等果实特征的变异进行了分析。结果表明,‘南月’实生后代的单果质量为0.64~2.15g,果实横径为10.0~16.4mm;果实可溶性固形物含量为9.1%-15.8%,其中有37%的单株果实可溶性固形物含量在12.0%以上;单果种子数为3~93粒,有18%的单株单果种子数小于25粒;果实颜色以蓝紫色和黑蓝紫色为主,比例分别为50%和42%;果实口感以中等和好2个等级为主,比例分别为50%和40%。在对果实的主要特征和经济性状进行评估的基础上,初步筛选出21个‘南月’实生后代优良单株。  相似文献   

13.
An understanding of phylogeography and population genetics is needed for a comprehensive long-term conservation management strategy. The Javan gibbon (Hylobates moloch), an Endangered species endemic to the island of Java, has been protected since 1924 but is threatened by ongoing habitat loss, habitat degradation, and the wildlife trade. We studied the phylogeography and population genetic structure of the Javan gibbon, to define the number of Evolutionary Significant Units (ESUs) in the species, and the population genetic structure in each ESU. We sampled 47 individuals, analyzing 35 for variation in mitochondrial DNA control region, 41 for variation in 8 nuclear DNA microsatellites, and 13 for variation in 45 nuclear DNA single nucleotide polymorphisms (SNPs). We found support for two ESUs across the species range: a western ESU, extending from Ujung Kulon to Gunung Gede–Pangrango, and a central ESU, extending from Gunung Masigit–Simpang–Tilu to Gunung Slamet. Analysis of molecular variance and population structure analysis indicate significant structuring in the western ESU between Ujung Kulon and Gunung Halimun–Salak–Gede–Pangrango, and little to moderate structure in the central ESU, underscoring the importance of conserving as many populations as possible to preserve the full array of genetic diversity in this species. Our results will inform future more comprehensive population genetic surveys and the conservation genetic management of the Javan gibbon. This study demonstrates the importance of genetics when designing conservation management strategies for endangered primates.  相似文献   

14.
Regulation of tomato fruit growth by epidermal cell wall enzymes   总被引:12,自引:0,他引:12  
Water relations of tomato fruit and the epidermal and pericarp activities of the putative cell wall loosening and tightening enzymes Xyloglucan endotransglycosylase (XET) and peroxidase were investigated, to determine whether tomato fruit growth is principally regulated in the epidermis or pericarp. Analysis of the fruit water relations and observation of the pattern of expansion of tomato fruit slices in vitro , has shown that the pericarp exerts tissue pressure on the epidermis in tomato fruit, suggesting that the rate of growth of tomato fruit is determined by the physical properties of the epidermal cell walls. The epidermal activities of XET and peroxidase were assayed throughout fruit development. Temporal changes in these enzyme activities were found to correspond well with putative cell wall loosening and stiffening during fruit development. XET activity was found to be proportional to the relative expansion rate of the fruit until growth ceased, and a peroxidase activity weakly bound to the epidermal cell wall appeared shortly before cessation of fruit expansion. No equivalent peroxidase activity was detected in pericarp tissue of any age. It is therefore plausible that the expansion of tomato fruit is regulated by the combined action of these enzyme activities in the fruit epidermis.  相似文献   

15.
In Japanese pear, the application of GA3+4 during the period of rapid fruit growth resulted in a marked increase in pedicel diameter and bigger fruit at harvest. To elucidate the relationship between pedicel capacity and fruit growth and to determine the main factor responsible for larger fruit size at harvest, fruit growth and pedicel vascularization after GA application were examined and the carbohydrate fluxes were monitored in a spur unit by non-invasive techniques using 13C tracer. Histological studies of fruit revealed that GA increased the cell size of the mesocarp but not the cell number and core size. The investigation of carbon partitioning showed that an increase in the specific rate of carbohydrate accumulation in fruit or the strength of fruit should be responsible for an increase of fruit weight in GA-treated trees. Observation of pedicel vascularization showed that an increase in pedicel cross-sectional area (CSA) by GA application mainly resulted from phloem and xylem CSA, but it is unlikely that an increase in the transport system is the direct factor for larger fruit size. Therefore, it can be concluded that larger fruit size resulting from GA application during the period of rapid fruit growth caused an increase in the cell size of the mesocarp and increased carbon partitioning to the fruit. Although GA is closely involved with pedicel vascularization, it seems that photosynthate accumulation in fruit is limited by the sink strength of fruit rather than by the transport capacity of the pedicel.  相似文献   

16.
不同材质果袋春夏季节套袋对黄瓜果实发育和品质的影响   总被引:11,自引:0,他引:11  
以“冬冠3号”黄瓜品种为试材,于春夏生长季节(4—7月份)在日光温室中研究了白膜袋、鲜膜袋、白纸袋和黄纸袋4种套袋处理对黄瓜果实微环境、果实生长发育和营养品质及农药残留的影响。结果表明:不论晴天还是阴天,所有套袋处理的袋内光照强度降低,相对湿度增大,温度提高;白纸袋增温效果最好,鲜膜袋内相对湿度最高,黄纸袋内光照最弱。单株单瓜套袋和单株果实连续套袋试验均表明,套袋后果实鲜重增长加快,瓜长度增加,瓜皮色显著变浅。连续套袋后,单瓜重普遍提高,大头瓜率降低,但化瓜率、弯瓜率和尖头瓜率增加;游离氨基酸含量提高;维生素C含量无显著变化;叶绿素和类胡萝卜素的含量普遍降低;可溶性蛋白质含量白纸袋和鲜膜袋的提高,黄纸袋和白膜袋的降低,但与CK间的差异均未达到5%显著水平。套袋可有效降低果实中氧化乐果的残留量,其中黄纸袋效果最好,其次为鲜膜袋、白膜袋和白纸袋。综合考虑各指标,认为春夏季节黄瓜果实套袋栽培应优先选用白纸袋,鲜膜袋和白膜袋不适宜在该季节使用。  相似文献   

17.
辣椒果实性状的遗传分析   总被引:4,自引:1,他引:3  
以6个辣椒品种并按(1/2)n(n-1)双列杂交法配制的15个杂交组合为材料,根据Hayman分析法估算了辣椒果实5个性状的遗传模型和遗传参数。结果显示,果长、果肉厚和结果数的遗传符合“加性-显性”模型,果宽和单果质量不符合“加性-显性”模型,还存在显著上位性效应。遗传参数估算表明,5个果实性状遗传是以加性效应为主,但不同果实性状显性效应有较大的差异,果肉厚的显性效应最大,其次是果长和结果数,果宽和单果质量最小。  相似文献   

18.
Covering apple fruits with double layer waterproof bags to enhance fruit quality and evenness of blush colour is typical on many cultivars in Korea and Japan. Aminoethoxyvinylglycine (AVG) applied to unbagged apple fruits at 3–4 weeks before commercial harvest reduces ethylene production in the fruit, delays fruit ripening and reduces pre-harvest fruit drop. Spray application of AVG to trees of bagged apples should have no effect on apple ripening as there is␣no direct contact with the fruit and the translocation of AVG in apple trees is regarded as negligible. However, preliminary experiments suggested that AVG applied to trees of bagged apples reduced pre-harvest fruit drop in “Kotgetsu” apples. This study investigated the effect of spray treatments of 125 ppm of AVG on fruit drop, fruit ripening (firmness, starch conversion and soluble solids) and ethylene production to whole trees with bagged or unbagged “Kogetsu” fruit, as well as sprays of only the bagged or unbagged fruit on trees on two orchards. AVG applied to whole trees with unbagged apples reduced fruit drop from an average of 58.9% to 10.4%, delayed starch conversion and decreased ethylene production. AVG applied to whole trees with bagged fruit was equally effective in reducing pre-harvest drop, delaying fruit ripening and reducing ethylene production. Application of AVG to unbagged fruit only was nearly as effective as application to whole trees with unbagged fruit but application to bagged fruit only had no effect on fruit ripening or ethylene production. Application of AVG to bagged fruit only did reduce fruit drop to an average of 42.5% but this was not as effective as spraying unbagged fruit only or whole trees with bagged fruit. Possible mechanisms for this effect are discussed.  相似文献   

19.
Duets in territorial, pair-living primates may function to maintain intragroup cohesion, promote intergroup avoidance, and assist in territorial and resource defense, as well as advertising and reinforcing pair bonds. Despite the absence of duetting in Javan gibbons (Hylobates moloch), recent playback experiments suggested that Javan gibbon songs also play a role in pair-bond advertisement as well as territorial and mate defense. However, playback experiments only assess motivations of the listener, which may not reflect the motivations of the caller. We conducted an observational study of naturally occurring female songs in two groups of Javan gibbons from July 2009 to March 2010 and from March to November 2011 in Gunung Halimun–Salak National Park, Indonesia. We investigated female singing rates in relation to singing location, daily path length, occurrence of intergroup encounters, feeding rate, allogrooming rate, and distance between pair mates. The two females produced 47 songs during 164 observation days. Females in the area of their home range that overlapped with neighboring groups sang more frequently than expected based on time spent in the area of overlap vs. the home range interior. Groups also had longer daily path lengths on days when females sang than on nonsinging days, and on days when they visited the area of overlap than on nonvisiting days. Our findings indicate that, like the duets of other pair-living territorial primates, female Javan gibbon songs function for territorial defense, but we found no support for other functions such as intergroup avoidance, resource defense, and pair-bond reinforcement.  相似文献   

20.
ABSTRACT. Within host trees, male and female Rhagoletis pomonella (Walsh) flies locate visually individual fruit of apple and hawthorn, which are sites of mating and oviposition. By measuring the diffuse reflectance spectra of both fruit and foliage and by using artificially pigmented natural fruit and artificial fruit mimics, we show that fruit hue is not as important in R. pomonella fruit detection as is intensity contrast of dark fruit against a bright background of light transmitted through foliage or skylight. In discussing the fruit detection system of R. pomonella , we compare it to that of vertebrate fruit consumers and seed dispersers.  相似文献   

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