盐度和营养盐对礁膜配子体发育的影响

礁膜(Monostroma nitidum)是我国重要的经济海藻之一,隶属于绿藻门,绿藻纲,石莼目,礁膜科,礁膜属。礁膜广泛分布于我国的东南沿海,生长在内湾静水处的岩石上或具有泥砂的石块上。日常所见的礁膜叶状体是配子体,为膜状,呈绿色或黄绿色,体软并具光泽。礁膜是绿藻中食用价值最高的一种,体软味美,我国南北沿海居民有食用。日本人也喜食“紫菜酱”(原料以礁膜为主,掺入少量紫菜,加入调味料,高压烹煮而成)。此外,礁膜还具有一定的药用价值,如清热化痰,利水解毒以及降低胆     

Biological Features of Flowering and Development of Male Gametophyte in Anthurium andreanum

The aim of this study is to follow each development stage of inflorescence in order to understand the biological feature of flowering and the development of male gametophyte in Anthurium andreanum “Arizona" and to try to find the optimum conditions for its pollination. The methods of dissection and paraffin section were adopted to examine the structural characteristics of anthurium’s tiny floret and the development of the microspore. All the florets of the anthurium arrange on the rhachis helically sub- tended by a colorful bract. Each tiny floret has one gynoecium, four tepals and four stamina. The bract and the florets show different colors during the whole blooming period. The ovary is bicarpellary and has two locules, each of which has one anatropous ovule. The placenta is of a central placentation type. The stylar canal cells not only can produce the secretory mucilage but also can release their own cytoplasm caused by their self-disintegration before the pistil reaches its maturity. The wall of the anther is composed of four layers: epidermis, endothecium, middle layer and tapetum. The tapetal cells and the middle layers’ cells degenerated completely dur- ing meiosis of microsporocytes. The pollen grains were 2-celled at the time of anther dehiscence. Early morning, when the inflores- cences stay at their fifth development stage, is the optimum opportunity for pistil to get pollen grains. The pollen-collection should be done at the end of the seventh stage.     

龙须菜新品系GL 家系F1 配子体的性状分析

本研究旨在为深入构建龙须菜(Gracilaria/Gracilariopsis lemaneiformis)育种体系提供基础数据。采用DTOPSIS综合评价法对实验室构建的龙须菜GL家系的F1配子体的性状进行分析与评价,以期把F1配子体的综合性状这一模糊量化指标转化为该株系对理想解的相对接近度Ci值的量化指标,进而对各藻株的综合性状优劣进行综合分析,为未来良种的杂交以及选育提供依据。所测的100株藻体中,线性生长速率变化范围为2.0~7.3%/d,变异系数为26.79%,标准差达到1.28,各藻株之间存在明显的差异。藻株的分枝数分布很不集中,变异极为显著,其平均数为1.93个,标准差为0.8,变异系数为41.17%,差异明显,变异幅度相对很大。主枝基部直径变化范围1.4~2.2 mm,标准差达到0.18,变异系数在3个性状中最小,为9.87%。线性生长速率、分枝数、基部直径等性状分布均呈现明显的正态分布特征,标准差分析显示,各性状相对本身参数变化幅度较大,说明F1配子体存在一定的性状变异,可以挑选性状差异大的藻种进行杂交以期获得优良藻种。DTOPSIS综合评价分析显示20、47、93、6、31株系综合性状的评价值比较高,为后期人工选育优良藻种提供依据。     

不同种类冷冻保护剂对海带配子体及孢子的毒性评价

为筛选用于海带超低温保存的冷冻保护剂,采用10%二甲基亚砜(DMSO)、10%甘油、10%蔗糖、10%乙二醇、10%DMSO+10%甘油、10%DMSO+8%葡萄糖、10%DMSO+10%蔗糖、10%DMSO+10%甘油+8%葡萄糖、10%DMSO+10%山梨醇等9种单一或复合冷冻保护剂,在0～4℃条件下分别对海带配子体和孢子进行处理,对配子体处理30 min、60 min、24 h,对孢子处理15、30、60 min,通过统计配子体细胞的存活率以及孢子萌发成配子体的比例,对不同种类的冷冻保护剂进行毒性评价。结果表明：9种冷冻保护剂均对海带配子体和孢子有一定的毒性作用,并且毒性随着处理时间的延长而增强。10%DMSO对海带配子体细胞的毒性最小,处理60 min后配子体细胞的存活率为100%;其次是10%乙二醇,处理30 min后配子体的存活率为100%;含10%甘油的单一或复合冷冻保护剂对配子体细胞毒性较大,处理后配子体的成活率显著低于DMSO和乙二醇组(P<0.05)。单一冷冻保护剂对海带孢子的毒性显著低于复合冷冻保护剂,除10%甘油组处理30、60 min外,其他单一冷冻保护...     

南瓜花粉母细胞减数分裂及雄配子体发育研究

[目的]研究南瓜花粉母细胞的减数分裂及其雄配子体发育过程,以期为南瓜花药培养等方面研究提供一定细胞学依据。[方法]采用爱氏苏木精染色-冬青油透明技术对南瓜"天虹"的花粉母细胞减数分裂及其雄配子体发育过程中细胞结构变化和染色体行为进行了观察研究。[结果]南瓜花粉母细胞在细胞核分裂过程中,核膜核仁于中期I消失,末期I重新出现,此时形成2个新月形的细胞核,两核之间出现成膜体,但未出现细胞壁,该成膜体在中期Ⅱ又逐渐消失,末期Ⅱ重新出现。第2次分裂纺锤体中央离心扩散的成膜体与第1次分裂两核相对的中央界面形成的成膜体相连,小孢子细胞壁向心产生。多数四分体中包含四个子细胞,少数还含有额外的小细胞。单核靠边期核仁由1个分解成2～3个或多个,进入有丝分裂前期,成熟花粉为二细胞型。1.0～2.0 cm长花蕾中多数花粉细胞处于单核期,可以将其作为花药或小孢子培养的取材依据。[结论]该研究结果为南瓜细胞遗传学方面的研究奠定了基础。     

Microsporogenesis and male gametophyte development in Prunus mahaleb Linn.

Microsporogenesis and male gametophyte development in Prunus mahaleb Linn. were assessed using a method combined of scanning electron microscopy (SEM) and paraffin sections. The results showed the following: (1) the anther underwent normal development and is tetrasporangiate. The tapetum was glandular; (2) cytokinesis occurred simultaneously with meiosis in the microspore mother cell, and the tetrads were tetrahedral; (3) after meiosis, microspores generated by microsporogenesis were more or less irregular in shape during the contraction period. As the microspore increased in size, mature three cell types pollen grains finally developed in the chambers; (4) mature pollen grains were observed by SEM. The shape of the pollen was nearly flat and triangular. There were three germinal furrows in the exine of the pollen with horizontal stripes. These findings provide a scientific basis for explaining the reproductive biological characteristics of the breeding resources of Prunus mahaleb, and microspore vacuolization is considered to be the main explanation for the low fruit set.     

同源四倍体青花菜雄配子体的发育过程

利用“爱氏苏木精染色—冬青油透明”技术, 观察研究了同源四倍体青花菜( 2n = 4x = 36)雄配子体的动态发育过程。结果表明: 同源四倍体青花菜与相应的二倍体在雄配子的整个发育过程上表现相似, 细胞核经一次有丝分裂产生营养核与生殖核, 生殖核再经一次有丝分裂形成两个精核, 最终形成3 - 细胞成熟花粉, 具4个或3个萌发孔; 雄配子体发育过程中异常频率为12114% , 败育主要发生在单核     

沸石培养基对大羽藓(Thuidium cymbifolium)配子体生长的影响

以大羽藓(Thuidium cymbifolium)的配子体为试验材料进行组织培养,通过观察外观变化并定期记录其一级分枝长度、一级分枝个数等指标,研究了沸石培养基对大羽藓配子体生长的影响。结果表明: 02%NaClO消毒60 s效果最好,以沸石为培养基7 d后污染率、死亡率均为0,存活率100%;沸石培养基促进大羽藓配子体的生长受沸石浓度、培养基pH值、琼脂浓度、蔗糖浓度的影响。沸石培养基促进大羽藓配子体生长的最适条件是: 沸石浓度20%、培养基pH值75、琼脂浓度10%。在此条件下,大羽藓30 d后一级分枝长度为344 cm、一级分枝数量达270个。     

嘉兰(Gloriosa superba L.)的胚胎发育研究

嘉兰(Gloriosa superba L.)的胚珠是倒生型,具双珠被和厚珠心。单个孢原细胞平周分裂,形成初生周缘细胞和初生造孢细胞,后者直接起大孢子母细胞的作用。四个大孢子线型排列。通常合点端大孢子是有功能的,但也见到珠孔端大孢子具功能。胚囊发育属蓼型。成熟胚囊是八核七细胞的。助细胞具丝状器,反足细胞具有传递细胞的某些特征。大孢子发生和雌配子体形成的过程中,胼胝质和多糖的积累和消失有一定的规律性。嘉兰花基数为3,子房上位,子房由三个合生的心皮组成,三室中轴胎座。在发育过程中胚珠经历了直生、弯生、横生和倒生的过程。内外珠被先后在造孢细胞形成后分化,在发育前期,内珠被长于外珠被,并由它形成了珠孔道,当外珠被伸长后与内珠被共同构成了珠孔。内珠被细胞层数恒定为两层,而外珠被细胞层数则变化于4～5层间。珠柄中的维管束多为螺纹,环纹导管和管胞组成,由胎座发出后经珠柄到合点端终止,内外珠被中均无维管束。厚珠心,珠心细胞为3～4层,由周缘细胞分裂形成。珠心细胞富含淀粉粒,其细胞解体缓慢,尤其珠孔端,直至成熟胚囊阶段,仍有很发达的珠心细胞。     

金钱松雌球花的形态构造及大孢子和雌配子体的形成

金钱松雌球花着生于树冠上部5a以上短枝顶端。成熟雌球花中央为1球花轴,其上螺旋着生苞鳞和珠鳞,珠鳞上着生2倒生胚珠,胚珠单珠被,珠心喙较厚,珠被唇顶部和内侧壁表皮为乳头状细胞,珠被中具溶生树脂道,珠被和珠鳞表皮下数层细胞将发育成种子的种翅和硬壳。花芽中胚珠原基出现至雌配子体卵细胞形成需5个月。1月胚珠原基出现。3月形成大孢子母细胞期的幼胚珠。3月下旬～4月上旬大孢子母细胞减数分裂形成大孢子。4月中旬雌球花迅速增长为胚乳游离核期。5月胚乳细胞壁形成,颈卵器原始细胞出现并发育为颈细胞、腹沟细胞和卵细胞,雌配子体成熟。