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1.
尖叶拟船叶藓原丝体发育特征研究   总被引:3,自引:0,他引:3  
将尖叶拟船叶藓[Dolichomitriopsis diversiformis(Mitt.)Nog.]孢子接种于Knop培养基上,置于恒温培养箱中培养,在光学显微镜下对其原丝体(protonema)发育特征进行了详细观察和记录。结果表明:孢子第2天就开始萌发,第6天时其萌发率达90%以上;原丝体系统由绿丝体(chloronema)和轴丝体(caulonema)构成,假根(rhizoides)产生于芽体基部,由轴丝体退化而成;配子枝原始细胞产生于绿丝体分枝的基部或轴丝体上的斜壁细胞;配子枝(game tophore)形成后其上各部位都可形成假根;孢子萌发类型为真藓型(Bryum-type)。  相似文献   

2.
垂蒴真藓原丝体发育特征的研究   总被引:8,自引:1,他引:7  
在室内培养垂蒴真藓(Bryum uliginosum)孢子的基础上,对其孢子萌发、原丝体发育及配子体发生的全过程进行了跟踪观察。结果表明:该种孢子萌发后直接产生绿丝体。而轴丝体和假根仅在绿丝体上产生;配子体原始细胞产生于绿丝体基部细胞或轴丝体上。由此可以看出:垂蒴真藓属于真藓型孢子萌发型(Bryum-type)。  相似文献   

3.
小扭口藓(Barbula indica)芽胞发育特征的实验研究   总被引:1,自引:0,他引:1  
在光照培养箱中人工对照培养小扭口藓(Barbula indica(Hook.) Spreng)的芽胞,显微镜下观察并记录其发育成配子体的全过程。结果表明:小扭口藓芽胞在3~4 d即可萌发;10 d左右开始分化出绿丝体、轴丝体及假根;18 d,轴丝体上的侧枝顶端细胞以分生缢割的方式产生单细胞或多细胞芽胞;40 d,轴丝体上开始出现配子体原始细胞;之后,配子体原始细胞发育成桑椹状的幼小配子体。还对芽胞形态发育、生理生态及配子体发生过程的特点进行了分析和讨论。  相似文献   

4.
为了解梨蒴珠藓(Bartramia pomiformis)孢子萌发和原丝体发育特征,在显微镜下观察室内人工培养的梨蒴珠藓单倍配子体发育过程。结果表明,梨蒴珠藓孢子吸水膨胀5 d后,开始破壁萌发,原丝体系统以丝状绿丝体为主,轴丝体在绿丝体上分化产生。培养22 d后,配子体在轴丝体细胞上分化产生。参照Nishida的标准,梨蒴珠藓孢子萌发类型为真藓型(Bryum-type)。这为梨蒴珠藓的人工扩繁提供了发育学基础资料。  相似文献   

5.
大帽藓(Encalypta ciliata Hedw.)原丝体发育特征的实验研究   总被引:6,自引:0,他引:6  
在人工培养大帽藓(Encalypta ciliata Hedw.)孢子的基础上,对其孢子萌发、原丝体发育及配子体发生的全过程进行行了观察、描绘和照相。实验结果表明:在大帽藓的原丝体系统中主要包括两种成分,即:粗短的丝状绿丝体和细长的柳枝状轴丝体。丝状绿丝体一般由4~6个短粗柱状细胞组成,而轴丝体则是由多数细长柱形细胞构成,其上间隔分布有2~5个细胞组成的棒状体,初生假根有或者无。同时,还对大帽藓原丝体发育的特征进行了分析和讨论,初步确定大帽藓孢子萌发属于新的孢子萌发类型——大帽藓型(Encalypta-type)。  相似文献   

6.
在人工培养大帽藓(Encalypta ciliata Hedw.)孢子的基础上,对其孢子萌发、原丝体发育及配子体发生的全过程进行了观察、描绘和照相。实验结果表明:在大帽藓的原丝体系统中主要包括两种成分,即:粗短的丝状绿丝体和细长的柳枝状轴丝体。丝状绿丝体一般由4~6个短粗柱状细胞组成;而轴丝体则是由多数细长柱形细胞构成,其上间隔分布有2~5个细胞组成的棒状体,初生假根有或者无。同时,还对大帽藓原丝体发育的特征进行了分析和讨论,初步确定大帽藓孢子萌发属于新的孢子萌发类型——大帽藓型(Encalypta-type)。  相似文献   

7.
为获取其孢子萌发类型与该属植物系统发育、生态选择以及生殖策略选择的相关性,该研究通过室内人工培养的方式,在微米量级下观察并描述了碎米藓属(Fabronia)碎米藓(F.pusilla)和东亚碎米藓(F.matsumurae)两种藓类植物孢子萌发、原丝体发育和配子体发生的过程。结果表明:(1)两种藓类植物孢子均为壁外萌发,均产生由1~15个半圆球形细胞组成的绿丝体(chloronema)短枝;(2)碎米藓在绿丝体顶端分化产生轴丝体细胞,东亚碎米藓未分化产生轴丝体(caulonema);(3)两种藓类植物配子体原始细胞均在绿丝体上分化产生。参照Nishida对藓类植物孢子萌发型划分标准,分析并确定了碎米藓属两种藓类植物孢子萌发型均为蓑藓型(Maromitrium-type),为碎米藓属的系统分类提供了发育学证据。  相似文献   

8.
中华缩叶藓孢子萌发与原丝体发育特征研究   总被引:2,自引:0,他引:2  
通过室内人工培养中华缩叶藓的孢子,在光学显微镜下详细观察了其孢子萌发、原丝体发育及配子体发生的全过程.结果表明:中华缩叶藓的孢子在壁内萌发,随后分裂产生块状原丝体;块状原丝体上可产生两种丝状体,一种是具疣的棒状原丝体,另一种是由长圆柱状细胞组成的轴丝体;配子体原始细胞只产生于块状原丝体上.根据中华缩叶藓的孢子萌发和原丝体发育特征,并参照Nishida对藓类植物孢子萌发类型的划分,确定中华缩叶藓的萌发孢子型应属于缩叶藓型(Ptychomitrium-type).  相似文献   

9.
通过对采自河北雾灵山海拔1500m的仙鹤藓(Atrichum undulatum)的孢子萌发以及原丝体发育的观察,发现仙鹤藓孢子无休眠现象,孢子接种3天左右萌发:其原丝体发育分为绿丝体和轴丝体两个阶段。扩大培养实验结果表明。仙鹤藓茎叶体在添加2%葡萄糖的MS培养基上,置于25℃/20℃、14小时光照/10小时黑暗、36μmol·m^-2·s^-1条件下培养.产生新生茎叶体最多,且茎叶体长势最好,可以获得大量无菌材料。仙鹤藓愈伤组织诱导实验显示,形成愈伤组织的最佳培养基为添加2%葡萄糖和1.0mg·L^-16-BA的MS培养基。  相似文献   

10.
0.2、0.4、1.0及1.5mg·L-1 4个浓度的N-(2-氯-4-吡啶基)-N'-苯基脲(CPPU)对无疣墙藓的孢子萌发没有显著影响,但抑制绿丝体伸长和侧枝生成,对芽体的分化有明显的促进,且芽体发生数随浓度升高而增加.  相似文献   

11.
易仁知  秦俊  黄清俊 《西北植物学报》2023,43(10):1760-1769
以穗花牡荆为研究材料,通过探究其花芽分化进程和生理特性,为花期调控技术提供成花机理。采用物候期观察和石蜡切片相结合的方法并测定花芽分化过程中相关生理指标,研究花发育过程中的形态和生理变化。结果表明,穗花牡荆花芽分化为一年多次分化型,其进程可划分为七个时期:未分化期、总轴花序原基分化期、初级分轴花序原基分化期、次级分轴花序原基分化期、小花原基分化期、花器官分化前期和花器官分化后期。同一植株不同位置花芽及同一花序中不同单花分化的进程不同,第一季花期后各阶段的花芽分化形态常存在重叠。花芽分化过程中不同时期叶片和花芽的可溶性糖和可溶性蛋白质含量均有上升下降的变化,总体上叶片中营养物质含量高于花芽保证营养供应。花芽分化过程中,IAA、ABA、CTK和GA3整体水平上先升后降有利于花芽分化进行。研究认为,花芽中大量的可溶性糖和蛋白质积累及较高的碳氮比,有利于穗花牡荆花芽形态分化顺利完成。低水平的GA3/ABA和IAA/CTK有利于花序的形成,ABA/CTK和ABA/IAA比值升高促进小花原基和小花萼片原基的分化, GA3/CTK、GA3/ABA和GA3/IAA比值升高促进花瓣原基、雄雌蕊原基发育。  相似文献   

12.
Buds were collected from hydras fed four days a week on different schedules. Independent of schedule, parents produced the same number of buds per week, but significant differences appeared in the number of buds detaching on particular days, and in the number of digestive cells present in the buds. Groups of buds collected from parents fed the same number of days (from one to three) during the previous four days contained statistically indistinguishable numbers of digestive cells despite the order or sequence of days on which feedings occurred. The number of digestive cells in all the freshly detached buds collected here can be accounted for by the growth of a bud primordium over a four day period of bud development and growth. Such a primordium would have about 3,600 digestive cells and grow at the rate of 0.33 cells per cell per day of feeding. The numbers of tentacles found on freshly detached buds are correlated with the number of feeding days and digestive cells present in the bud. Tentacles, therefore, may also form from primordia consisting originally of a specific number of cells.  相似文献   

13.
The position of the gametophytic bud was examined in relationto the development of protonema in the moss, Physcomitrium sphaericum. Positions of protrusion formation, of the development of protrusionsinto lateral filaments, and of the differentiation of protrusionsinto buds are restricted within the narrow regions of the filaments.The number of cells from the apical cell of the filament tothese positions are constant in any size filament. The growth pattern of the protonema is shown as follow. As afilament grows one-dimensionally through divisions of the apicalcell, new protrusions are produced successively on the 5th cellfrom the apical cell or on its vicinity. The cells which intervenebetween the apical cell and this protrusion increase in numberas the apical cell divides. When this protrusion is positionedat the 8th or 9th cell from the apex, it differentiates intoa bud or a lateral filament. This growth pattern is common toboth the main and lateral filaments. Buds are differentiated not only on caulonema cells in the mainand lateral filament, but also on chloronema cells at the baseof the lateral filaments. (Received December 14, 1981; Accepted April 24, 1982)  相似文献   

14.
金灰藓(Pylaisiella polyantha)配子体发生的实验观察   总被引:7,自引:2,他引:5  
金灰藓Pylaisiella polyantha (Hedw.)Grout孢子在光照培养箱中进行培养,实验组为含有Knop培养液的琼脂培养基质,对照组为无营养成分的琼脂培养基质。在光学显微镜下对配子体发生进行了观察、描绘和照相。结果表明:实验组和对照组孢子萌发所需时间相同,均为53.5h,萌发极相为1~4极。4d时,实验组萌发率为85.4%,对照组为54.1%;20d时,开始形成配子体芽原基;40d时,形成具假根、茎、叶的配子体,并形成两性器官。并对配子体发生过程的特点进行了分析和讨论。  相似文献   

15.
16.
In the course of their development the protonemata of Funaria hygrometrica produce two different substances which diffuse into the substrate. In the chloronema a thermo-labile growth-promoting substance is formed. In the caulonema, after about 10 days, a substance is produced which is thermostable and soluble in amyl alcohol, which can be dialysed, and which functions as a growth inhibitor. Both substances also influence bud formation. This is at an optimum only when there is a certain balance between these two substances.
This promotion is fundamentally different from that brought about by treatment with kinetin, because kinetin can function only as an additional factor in promoting bud formation. Very probably it acts as an agent which creates centres of attraction toward which morphogenetic substances are drawn. This assumption is supported by the fact that kinetin cannot be transported and therefore has no 'after-effect'. It probably functions only in the caulonema cell it penetrates. It converts every caulonema cell into a 'reaction cell'.  相似文献   

17.
金灰藓Pylaisiella polyantha(Hedw.)Grout孢子在光照培养箱中进行培养,实验组为含有Knop培养液的琼脂培养基质,对照组为无营养成分的琼脂培养基质。在光学显微镜下对配子体发生进行了观察、描绘和照相。结果表明:实验组和对照组孢子萌发所需时间相同,均为53.5h,萌发极相为1~4极。4d时,实验组萌发率为85.4%,对照组为54.1%;20d时,开始形成配子体芽原基;40d时,形成具假根、茎、叶的配子体,并形成两性器官。并对配子体发生过程的特点进行了分析和讨论。  相似文献   

18.
The structure of the plumule of Nelumbo nucifera Gaertn. and its feature covered with scale are seldom seen in dicotyledon. The fact that the plumule possesses scale is even more uncommon. This particular phenomenon is investigated by observing the differentiation of the plumule apex and the development of the leaf organs. After the seed is formed, the embryo has two young leaves and a terminal bud covered with scale. In the bud it has already differentiated the 3rd and the 4th leaf primordium and a shoot apex, the differentiation of which is very complex. So the structure of the plumule passes through 4 plastochrons altogether. It is made clear through observation and analysis that, before the 4th leaf primordium is formed, the transforma- tions of the shoot apex of the embryo in each plastochron are fundamentally alike. After the 4th leaf primordium is developed, the shoot apex becomes complex and there appear 3 different active cell regions which become the bases of vegetative bud of the seeding apex. The development of these 3 active cell regions will be stated in “The Structure of the Vegetative Bud of Nelumbo nucifera Gaertn. and the Nature of its Scales.” The apices of the plumule are almost slightly domed in structure. As a rule, their width is from 95 to 107 μ. Their height is from 17 to 20 μ during one plastochron. Before the 3rd leaf initiation, the anatomical structure of apices is examined and the fol- lowing zones may be delimited: zone of tunica initials, zone of corpus initials, peripheral zone, and zone of rib meristems. It is frequently observed that the cell of corpus in subapical peripheral zone develops periclinal division, which is the initial cell of leaf primordium; Procambium will appear before the stage of the appearance of leaf buttress. The apex of the plumule is in an apical position, but when the seedling is formed, as the developing leaves are alternate, the directions of the shoot apex are changed, simultaneously the base part of the leaf encloses the axis, and the adaxial meristem also differentiates the scale which encloses the terminal bud, thus placing the bud in axillary of the leaf and forming a zigzag phenomenon of the axis of the seedling. Above the basal adaxial side of the leaf primordium develops the scale of the plumule with meristem periclinal division of closely attached protoderm as its base. So the scale of the plumule of Nelumbo nucifera Gaertn. and the axillary stipule are of the same origin. To sum up, the scale of the embryo of Nelumbo nucifera Gaertn. is differentiated from the adaxial meristem of the basal part of the leaf primordium, and is the derivative part of the leaf. It has the same function as the coleoptile of the monocotyledon. Whether they are homologous organs or not is still to be investigated.  相似文献   

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