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121.
为探讨干旱胁迫对油松非结构性碳水化合物(NSC)的影响及其响应机制,以2年生油松幼苗为对象,设置适宜水分、轻度、中度和重度干旱胁迫处理(即80%、60%、40%和20%田间持水量),比较幼苗在不同胁迫时间(15、30、45和60 d)各器官NSC含量的变化规律。结果表明:不同干旱胁迫处理程度与时间对油松幼苗当年生叶、1年生叶、茎、粗根和细根的可溶性糖、淀粉及总NSC含量均具有显著交互作用。干旱胁迫15 d时,当年生叶NSC含量在干旱胁迫处理显著低于适宜水分处理,细根NSC含量在轻度和重度胁迫处理显著高于适宜水分处理。干旱胁迫45 d时,随着胁迫程度增加,当年生叶、1年生叶、茎、粗根和细根淀粉含量均呈增加趋势。干旱胁迫60 d时,随着胁迫程度增加,细根淀粉含量呈下降趋势,细根可溶性糖及NSC含量在胁迫处理显著低于适宜水分处理。综上所述,油松幼苗胁迫初期,NSC优先供给细根以促进吸收水分,而长期胁迫,将导致NSC向下运输受阻,根系生长和吸收功能下降。这种NSC对干旱胁迫阶段性响应策略的揭示为东北地区油松幼苗造林最佳时间选择及水分管理提供数据支持。 相似文献
122.
The cuticle of concavicarids (Arthropoda: Thylacocephala) from the early Famennian (Upper Devonian) of the Holy Cross Mountains, Poland was studied with respect to its microstructural details. Investigated laminated cuticle with phosphatic/organic composition, possesses two different kinds of microstructure with assumed sensory functions. The first kind consists of circular depressions, each located in the central area of characteristic polygons forming the carapace exterior ornamentation. These depressions are interpreted as sealed during phosphatisation processes setal lumens. The second kind occurs exclusively in carapace margins. These intracuticular microstructures occur as elongated tubular structures, circular to oval in cross section, penetrating the cuticle interior but not reaching its surface. They form a thin belt with a kind of ‘sensory fields’ on the dorsum and a wider belt in the ventrocaudal part of the carapace. These belts are connected in the rostral and caudal area, forming a continuous sensory zone encompassing each valve. These structures are very similar to crustacean organule canals, and the dorsally situated ‘sensory fields’, suggest some similarity to crustacean sensory dorsal organs. This possible sensory system is the oldest of this kind found in Thylacocephala. Its morphology and presumed canal walls mineralogical composition suggests crustacean affinity of Thylacocephala. 相似文献
123.
以文冠果新梢为试验材料,通过分析文冠果新梢生长发育过程中的茎尖、茎段、叶片的多酚、类黄酮、单宁及相关酶(苯丙氨酸解氨酶、多酚氧化酶)活性,研究了文冠果新梢枝条发育过程中不同部位酚类物质的积累规律及相关酶活性的变化规律。结果显示:(1)文冠果新梢生长期内(4~9月)随着季节的变化,多酚、类黄酮、单宁等酚类物质含量总体上呈现上升趋势,新梢同一时期不同部位的多酚、类黄酮、单宁等酚类物质含量的分布情况相似,皆为:叶茎尖茎段。(2)文冠果不同发育时期的茎叶苯丙氨酸解氨酶活性大小为:新梢幼嫩茎段及相应叶片半木质化茎段及相应叶片木质化茎段及相应叶片;新梢叶片的多酚氧化酶活性显著高于茎段,茎尖的最低;文冠果叶片有着极强的抗氧化能力,对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除率最高可达98.13%。(3)在4月29日前后,文冠果新梢各部位多酚、类黄酮和单宁含量上升趋势有显著差异,各部位苯丙氨酸解氨酶活性最低,而多酚氧化酶活性最高,木质化程度不同的茎段DPPH·清除率均降至最低,表明4月29日是文冠果新梢生长期的一个重要过渡生长阶段。(4)文冠果的新梢多酚、类黄酮、单宁之间呈极显著正相关关系;多酚、类黄酮、单宁与DPPH·清除率存在极显著正相关关系,与多酚氧化酶活性呈显著正相关关系,与苯丙氨酸解氨酶活性之间相关性不显著。研究表明,酚类物质含量是影响文冠果无性繁殖的主要因素,酚类物质含量越低,文冠果的扦插、嫁接、组培的成活率越高;新梢多酚、类黄酮、单宁等酚类物质含量在生长初期最低,后随着新梢的生长呈现显著上升趋势;文冠果无性繁殖最好在新梢生长初期进行,最佳时间为4~5月中旬。 相似文献
124.
Sid Staubach Peter Schützner Roger P. Croll Annette Klussmann-Kolb 《Zoomorphology》2008,127(4):203-212
This study describes the innervation patterns for the cerebral nerves which project to the cephalic sensory organs (CSOs)
in the opisthobranch Haminoea hydatis (Linnaeus 1758) and uses axonal tracing techniques (backfilling) to reveal the central cellular origins for these cerebral
nerves. Cell clusters projecting into the cerebral nerves can be defined by their positions in the ganglion relative to other
clusters, nerve roots and lobes. The number of cell clusters and the relative sizes of somata are constant in a given cluster,
whereas the absolute number of somata and absolute sizes of single somata in a given cluster increase with the size of the
animal. Additionally, the invariable morphological characteristics of the cell clusters are used to define criteria for the
assessment of possible homology for the clusters innervating the CSOs in Opisthobranchia. The data suggest two different strategies
to accommodate the increasing body size; first, the additions of nerve cells and second, the growth of nerve cells.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
125.
The gene Brassica campestris male fertility 13 (BcMF13, GenBank accession number EF158459) was isolated as a reproductive organ-specific gene from Chinese cabbage (Brassica campestris L. ssp. chinensis Makino, syn. B. rapa ssp. chinensis). It is exclusively expressed in stage four and five flower buds of fertile lines and is most strongly expressed in stamens.
Here, we report a functional characterization of this BcMF13 gene in the antisense-silenced plants. The inflorescence of the BcMF13 mutant was compacted with anthers curved outside. The fertility of this mutant was greatly reduced with less than 5 seeds
per silique. Under scanning electron microscopy, the mutant demonstrated numerous shriveled pollen grains with deep invaginations.
The frequency of normal pollen grains was just 45.34%. The pollen mother cell, the tetrad, and the mature pollen of the BcMF13 mutant were abnormal resulting in the poor pollen vitality. Germination test in vivo suggested BcMF13 delayed the pollen tubes’ extension in the style. All these indicated BcMF13 had a vital role in pollen development of Chinese cabbage. 相似文献
126.
月平均采集并解剖滇蛙14—16只(雌雄约各半),测量体长、体重、脂肪体重、精巢重、卵巢重、精巢体积和输卵管直径等。以体长为协变量做协方差分析,结果显示,精巢重、卵巢重、精巢体积、输卵管直径在年周期内差异显著,呈周年规律性变化。滇蛙的繁殖期为4—6月,5月下旬至6月上旬为繁殖高峰。异速生长分析和回归分析结果显示,性腺发育与体重和体长多呈正异速生长(b>1),个体增长对性腺的发育有显著影响。个体较大的滇蛙年生殖频次至少为2次,这是提高繁殖成功率的繁殖策略之一。性腺发育与脂肪体重呈负异速生长(b<1)。脂肪体为繁殖和冬眠提供能量储备,脂肪体重在繁殖高峰期达最小值。少数脂肪储存不足的个体通过延迟冬眠时间积累能量,以便安全越冬。相关性分析和交叉相关分析结果显示,两性生殖腺的发育具有显著的相关性,但生殖腺的发育并非完全同步。雄蛙精巢的发育具有一定的滞后性,因为卵的成熟比精子的成熟需要更长的时间。但精巢体积和输卵管直径发育具同步性,这恰是为授精做好了准备。 相似文献
127.
Einarsson S Andersson K Wallgren M Lundström K Rodriguez-Martinez H 《Theriogenology》2009,71(2):302-310
The objective of this study was to determine the short and long term effects of a gonadotropin-releasing hormone (GnRH) vaccine (Improvac™ Pfizer Ltd.), on sexual maturity, development of the reproductive organs, and the morphology of caudal epididymal spermatozoa in non-castrated male pigs. The pigs were slaughtered 4, 16 or 22 weeks after the second Improvac™ vaccination. A total of 80 crossbred non-castrated male pigs were included in this study comprising two experiments, a short-effect (Experiment 1) and a long-effect (Experiment 2). The first experiment included 56 pigs, 24 of them were maintained as controls and 32 were vaccinated twice, and slaughtered 4 weeks after the second vaccination. The second experiment included 24 pigs, 12 controls and 12 vaccinated twice, and slaughtered either 16 weeks (n = 6) or 22 weeks (n = 6) after the second vaccination. None of the immunized pigs was sexually mature at slaughter, i.e. 4, 16 or 22 weeks after second vaccination. Corresponding results of the control pigs showed that 50% had reached sexual maturity at the age corresponding to 4 weeks after the second vaccination, and 100% at slaughter 16, respectively, 22 weeks after vaccination. At 4, 16 and 22 weeks after second vaccination both testes weight and bulbourethral length were significantly reduced (p < 0.001). The percentages of proximal droplets and abnormal heads were significantly lower in the control pigs than in the immunized pigs at slaughter 4 weeks after vaccination, whereas distal droplets were higher. For the other morphological parameters no significant differences were seen, but all mean values except for acrosome defects were numerically lower in the control pigs compared with the immunized pigs. For pigs slaughtered 16 or 22 weeks after vaccination, the vaccination effect was significant for percentages of proximal droplets, distal droplets, acrosome defects, acrosome abnormality and abnormal heads (p = 0.017-0.001). The immunization clearly disrupted the number and morphology of the interstitial Leydig cells, lasting throughout the study period (4-22 weeks after vaccination). Spermatogenesis was also clearly affected in the immunized pigs, to various degrees, from mild disruption (spermatocyte loss, decrease of the normal number of layers of germ cells) to severe loss of germ cells including tubuli with Sertoli cells-only (complete disappearance of germ cells), also covering the entire study period. The results indicated that the effect of immunization persisted for at least 22 weeks after the second vaccination. 相似文献
128.
柄天牛属八种(亚种)雌性生殖器的比较研究(鞘翅目,天牛科,天牛亚科) 总被引:1,自引:1,他引:0
记述了柄天牛属8个种(亚种)的雌性生殖器,比较研究了该属雌性生殖器的结构特点.结果表明:柄天牛属雌性生殖器在骨杆形状、受精囊管长短等方面存在不同程度的差异;通过雌性生殖器特征对比,黄颈柄天牛、暗胸柄天牛、红腹柄天牛三者虽然存在一定差异,是否应作为同一种依据不足,故仍保留亚种地位. 相似文献
129.
The effect of expression of the enzyme producing nitric oxide on Drosophila melanogaster morphogenesis was studied using ectopic expression of a truncated splice form of the enzyme that has a dominant negative effect on the full-length enzyme form. The suppressed enzyme expression was shown to affect the cell polarity and movement as well as the structural pattern of organs during Drosophila development. The effect of nitric oxide production on the intercellular distribution of significant factors of cell polarity, protein products of the Strabismus and Prospero genes, has been revealed. 相似文献
130.
Hiroyuki Ijima Hiroshi Mizumoto Kohji Nakazawa Toshihisa Kajiwara Taku Matsushita Kazumori Funatsu 《Biochemical Engineering Journal》2009,47(1-3):19-26
In our previous pre-clinical study with pig hepatic failure, an artificial liver with polyurethane foam (PUF)/primary porcine hepatocyte spheroids had superior curative effect. We examined the effect of hepatocyte growth factor (HGF), also known as scatter factor, on the quick formation of hepatocyte spheroids and albumin production. Spheroids were formed in the pores of PUF within 3 days regardless of addition of growth factors. In particular, spheroids were formed within 1 day in medium containing 100 ng/ml HGF and 50 ng/ml epidermal growth factor (EGF). 10,000 ng/ml HGF was effective for albumin production, but the activity dramatically decreased after 6 days in EGF-free medium. On the other hand, 100 ng/ml HGF was effective for albumin production in EGF-containing medium. Albumin production rate with ≥1000 ng/ml HGF was about 1.5 times higher than that with 100 ng/ml HGF. Furthermore, albumin production rate at 3 weeks was about 1.5 times higher than that at 2 days with 1000 ng/ml HGF. The maintenance of albumin production rate depended on the activity of the individual cell and not cell growth. In other words, we were able to show the effectiveness of HGF for functional hepatocyte organoid formation in PUF pores. 相似文献