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1.
夜蛾科卵的分类(鳞翅目)(一)   总被引:6,自引:0,他引:6  
卢筝  丁传生 《昆虫学报》1995,38(1):97-102
本文记述了12种夜蛾的卵。 从不同方向的电镜像片显示出他们的形状和被用作分类的特征,包括精孔区的形态特征,纵脊和横道的状况,气孔的位置、形状和大小,小室的形状和表面结构,以及腹面的细微构造。  相似文献   

2.
夜蛾科卵的分类(三)   总被引:1,自引:0,他引:1  
周静若  丁传生 《昆虫学报》1995,38(4):471-474
本文记述了13种夜蛾卵的形态,从不同方向的电镜照片显示出它们的形状和分类特征。  相似文献   

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温度及土壤含水量对淡剑纹灰翅夜蛾死亡率的影响   总被引:1,自引:1,他引:0  
淡剑纹灰翅夜蛾Spodopteradepravata(Bulter)在 2 2 ,2 5 ,2 8,3 1 ,3 4,3 6,3 8℃恒温条件下卵孵化率分别为 96. 0 0 ,91 .0 0 ,83. 90 ,84. 81 ,83 . 60 ,80 %和 0。高龄幼虫在低温环境下 ,一般随温度的降低、时间的延长死亡率增加。过冷却点为 (-6. 81± 1 . 63 )℃ ,体液冰点为 (-3 .5 1± 1 . 5 6)℃。 1 0 %土壤含水量时该虫羽化率最高 ,40 %及其以上羽化率为 0。  相似文献   

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卵大小与数目的权衡是繁殖生态学研究的重点之一,生理限制假说预测雌性自身能量储存决定了对单个卵能量的分配,形态限制假说认为雌性形态亦会限制卵大小或(和)数目。本研究对敏麻蜥雌性形态和繁殖相关指标进行分析,以验证上述假说。结果表明:敏麻蜥的卵短径随着雌性尾基宽的增加而增大,卵长径、卵体积和窝卵数随着雌性腋跨距的增大而增大;此外,卵重和窝卵数随着雌性身体状况指数的增加而增加;卵大小与数目之间呈显著正相关而不存在权衡,表明雌性通过同时增加卵大小与数目来增加繁殖投入;敏麻蜥的卵形状与雌体局部形态均存在异速增长现象,且卵形状异速增长斜率小于雌性局部形态异速增长的斜率;在去除窝卵数的影响后,两者的异速增长斜率却无显著差异。研究表明,敏麻蜥雌性的形态可以限制卵大小与数量;具有较好身体状况的雌性可以产更重且更多的卵;卵重与数目之间没有权衡;雌性形态限制是导致卵形状异速增长的潜在因素。  相似文献   

7.
花粉与孢子为形态学上的重要实体,它反映出植物进化的某些侧面与事实。在孢子外壁的各种特征中,萌发孔被认为是最保守的。菌藻类植物的孢子为原始型(其萌发孔不明显)颈卵器植物的孢粉为三型的(具三裂缝,单裂缝和无裂缝);而被子植物的花粉为多型的(具沟、沟孔、孔等等,且在数目与形状上有很多的变化)。三型孢粉为被子植物前身的颈卵器植物的特征,它在被子植物中的出现可能被看成是提供了一种表明该类中原始分类群的指示。面对这—背景,我们主张被子植物在其进化系列中是三种系发生的,有三条独立的系统发育主干,即单子叶植物主干、木兰类双子叶植物主干和毛茛类双子叶植物主干。  相似文献   

8.
大银鱼卵膜孔结构的电镜观察   总被引:14,自引:2,他引:14  
扫描电镜下,大银鱼成熟卵卵膜孔区域呈现奇异的放射沟脊状结构。在授精开始的30秒内,测得卵膜附近约86%的精子沿着凹沟进入精孔管;还拍摄到了通过卵孔中心的纵切面映象,通过电子计算机模拟,验证了卵膜孔的这种结构,为精子的云集和进入精孔管所提供有利条件,从而,于泥鳅之后又发现了一种真骨鱼,其精子入卵除化学因素外,还存在着不容忽视的机械动力因素。  相似文献   

9.
桑粉虱形态研究   总被引:4,自引:0,他引:4  
研究描述了容易与杨梅粉虱混淆的重要害虫桑粉虱Pealius mori(Takahashi)成虫、卵、1~4龄若虫及蛹的形状、分类特征,包括成虫的体长、体色、触角、单眼、复眼、口器、翅、足及雌雄外生殖器;卵的形状、大小、卵色及卵柄;1~4龄若虫及蛹的形状、大小、体色、体周的刚毛、触角、口器、足、管状孔、盖瓣、舌状器及腹沟等。并比较桑粉虱与杨梅粉虱的主要分类特征。  相似文献   

10.
本文详细描述了尚未报道的燕角叶蚤端突亚种Ceratophyllus farreni chaoi幼虫形态并与同属的禽角叶蚤欧亚亚种Ceratophyllus gallinae tribulis幼虫进行比较。 这两亚种的共同特征是:头部,1—3胸节,1—9腹节的毛序和感觉孔数目,肛柱形态,肛梳2列,第10腹节的感觉孔数目和腹面的刚毛数目。而其鉴别特征是:破卵器形态,大颚的齿数,1胸节至9腹节背板上前排感觉孔与前排鬃的位置,肛梳和肛柱的刚毛数目。  相似文献   

11.
舞花姜种子的解剖学和组织化学研究   总被引:13,自引:2,他引:11  
吴七根  廖景平   《广西植物》1995,15(2):146-153
舞花姜种子表面只许多表皮毛,基部具黄白色的种阜状结构。假种皮着生于种阜结构内缘,基部筒状,中上部指状分裂;假种皮细胞长条形.内含许多细小淀粉粒。种皮由外珠被发育而来.可划分为外种皮、中种皮与内种皮。外种皮由具3—5(6)层表皮细胞的复表在构成,最外层的一些表皮细胞向强突起形成表皮毛。中种皮由下皮层、半透明细胞层、中种皮薄壁细胞层与色素层构成。下皮层由一层下皮细胞构成,细胞内充满结合有单字的红褐色色素;半透明细胞含有与脂类结合的淡黄褐色无定形块状物,中种皮薄壁细胞内无色素或任何颗粒状物;色素层为中种皮最内方的一层,细胞体积大、充满与单宁结合的红褐色色素。内种在由一层体积小、壁局部增厚的砖形薄壁细胞构成,其机械保护作用小。种子在珠孔区分化出珠孔领、孔盖及种阜状结构。珠孔领为异形型,孔盖不具石细胞硬层。种阜状结构以其细胞层数增多、壁增厚并本质化的复表皮加强了珠孔区的机械保护作用。合点区内种皮出现缺口.缺口间充满通常呈多角形的合点区色素细胞,其整体轮廓为长条形。外胚乳细胞壁平直,细胞内充满淀粉粒,部分细胞还含有少量的蛋白质与脂类:近合点外胚乳形成一薄区。内胚乳细胞含有蛋白质、脂类与淀粉.其细胞轮廓清楚,椭圆形或不规?  相似文献   

12.
泥鳅精子入卵的动力作用   总被引:13,自引:0,他引:13       下载免费PDF全文
在扫描电镜下,泥鳅成熟卵卵膜孔外围呈现完整的左涡旋状结构,受精时精子是顺着涡旋的流线进入卵膜孔。涡旋纹理接近对数螺线。本文分析了真骨鱼类的受精因素,除已知的化学因素外,还存在物理因素。也讨论了泥鳅成熟卵卵膜孔形态形成的必然性。  相似文献   

13.
蔡联炳 《植物研究》2002,22(3):278-284
生殖器官性状一直是禾本科植物分类的主要依据 ,但由于各个性状所附实体的形态特点、着生位置、发育程度和环境饰变的差异 ,其分类价值是不尽相同的。为了克服该类性状使用上的种种弊病 ,本文特对主要宏观性状的分类价值进行了评述 ,总结了它们在应用中各自适宜的等级范围。其中象花序的类型、小穗的着生、小花和果实的形状等价值较高 ,通常适合于族级以上类群的划分 ;花序的形状、小穗的排列、果实的类型等价值偏低 ,通常适合于属、种级类群的区分 ;而花序的长短与粗细、小穗轴、内稃等价值较低 ,通常适合于种级或种级之下类群的鉴分。  相似文献   

14.
Anatomical studies of unfertilized undeveloped seeds from open- and control-pollinated fruits of ten facultative apomictic Citrus cultivars were carried out with the aid of light and epifluorescence microscopes. With or without pollination, adventive embryos autonomously developed at all positions in the nucellus in all cultivars. The adventive embryos initiated at the chalazal end of the nucellus were more vigorous than those initiated at the micropylar end. Because of the lack of endosperm and poor seed development, however, all adventive embryos within the unfertilized seeds terminated their development at the globular or early cotyledonary stages and were unable to germinate under natural conditions. The capability of unfertilized seeds to develop varied from species to species. Growth of the adventive embryos was dependent on nucellus size, but the growth rate of adventive embryos relative to nucellus size was different in different species. Neither pollination, fertilization nor subsequent zygote and endosperm development further stimulated adventive embryo initiation. Conversely, pollination and subsequent fertilization of other seeds in the same fruit slightly, but significantly, suppressed adventive embryo growth in the unfertilized seeds. These facts concerning adventive embryogenesis in unfertilized seeds indicate that neither pollination nor fertilization is essential for in vivo adventive embryogenesis and that normal endosperm is necessary for perfect development of adventive embryos initiated only in the micropylar half of the nucellus.  相似文献   

15.
Mc Gahan , Merritt W. (Central Research Labs., United Fruit Co., Norwood, Massachusetts.) Studies on the seed of banana. II. The anatomy and morphology of the seedling of Musa balbisiana. Amer. Jour. Bot. 48(7): 630–637. Illus. 1961.—The first external evidence of germination of the seed of Musa balbisiana is the displacement of the micropylar plug by the elongation of the hypocotyl-radicle axis. As the hypocotyl and epicotyl emerge from the micropylar collar, the seminal adventitious roots become apparent and the cotyledonary sheath surrounding the epicotyl emerges as a coleoptile-like structure. Subsequent growth results in the elongation of the first leaves beyond the cotyledonary sheath and the rapid elongation of the adventitious root system. The vascular transition occurs between the cotyledon and the radicle. The sheath is considered to be only analogous to the coleoptile of the grasses.  相似文献   

16.
Sperm penetration and the formation of a fertilization cone in the micropylar canal of the egg of the common carp were examined by electron microscopy. The overwhelming majority of inseminated eggs fixed without immersion in fresh water showed that the first spermatozoon had penetrated into the ooplasm before the cortical reaction had occurred, and in many cases had formed a fertilization cone to plug the micropylar canal. At this stage the sperm head was usually located at the base of the cone, and the tail part did not participate in the formation of the cone. Inseminated eggs fixed soon after immersion in fresh water showed that the elevation of the fertilization membrane and the simultaneous recession of the fertilization cone often permitted the penetration of a few supernumerary spermatozoa into the perivitelline space near the micropylar canal, but polyspermic fertilization was never observed. The mechanism of the block to polyspermy in the egg of the common carp is discussed in connection with the fertilization cone.  相似文献   

17.
The structure and distribution of laticifers has been studied in the bulb scales of 52 species and varieties of Allium. Differences in laticifer position, shape, and pitting in the cross wall of the observed specimens support Traub's separation of the subgenera Amerallium and Allium within the genus Allium. If the species examined are representative, anatomical evidence also justifies the distinction of the section Melanocrommyum and the subsection Cepa.  相似文献   

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