蔬菜作物的组织培养

经济作物中有一些属于杂合子型植物(heterozygote),例如马铃薯、球茎和鳞茎植物以及果树、花卉等植物。这类植物如用种子繁殖,它们的后代便会出现各种变异,不能保持原来品种的特性,因此一般均采用无性繁殖。近年来植物组织和细胞培养的技术与研究获得了飞跃的发展,应用这一技术来繁殖蔬菜作物,不仅使繁殖速度可以极大地增加,而且使不易用常规无性繁殖方法来繁殖的植物,也获得了新的繁殖途     

球根花卉的引种

西安植物园从1980年开始对球根花卉进行了引种栽培。现有郁金香75个品种,欧洲水仙37个品种,风信子8个品种,百合6个品种,还有银莲花、花毛茛,番红花、大花鸢尾、石蒜等。郁金香百合科植物。鳞茎卵形,叶片3一弓枚,条状披针形至卵状披针形。花色有红、橙、黄、紫、白等,花形单瓣、重瓣、花瓣边缘波状、齿毛缺刻等。中日照植物,喜富含腐殖质、排水良好的砂质壤土。鳞茎秋季种植,翌年春季发芽,4月开花     

由水仙愈伤组织产生再生植株

水仙在大田条件下的繁殖率是很低的。利用组织培养技术快速繁殖水仙已进行许多探索。本文报道从水仙鳞片愈伤组织长期培养物高频率地再生植株。材料和方法供试材料为中国水仙(Narcissus tazetta var.chinensis Roem.)的鳞茎。鳞茎用0.1%升汞溶液表面灭菌20分钟,经无菌水多次冲洗后,将较内层的鳞片基部切成约27mm~3切块(带有鳞茎盘)作外植体。     

中国水仙的核型分析和小孢子发生中的细胞学研究

中国水仙(Narcissustazettavar.chinensis)只开花不结实,以鳞茎营养繁殖。对中国水仙的染色体倍性有不同的报道。对中国水仙的核型分析,支持它是三倍体的观点,但其核型也显示出了异源三倍体的倾向。在小孢子母细胞减数分裂过程中,染色体的异常行为多表现为:中期出现单个染色体游离在纺锤体外面、在后期出现的染色体桥和落后染色体、在末期出现的单个染色体游离在细胞核外形成微核的现象。这些异常现象引起小孢子的败育,也支持中国水仙为三倍体植物的观点。     

石蒜鳞茎的新用途

石蒜科植物石蒜、水仙等的鳞茎,含有多种生物碱,既有毒又具有一定的药用价值。如水仙鳞茎捣烂可敷治痈肿,提取物有抗癌和抗病毒作用;石蒜鳞茎有祛痰、利尿、解毒、催吐作用,亦可作农药。     

中国水仙与欧洲水仙品种RAPD指纹的研究

利用随机多态性DNA(RAPD)技术对中国水仙和欧洲红口水仙共6个品种进行了分析。选用了12个10bp引物共扩增出119条DNA片段。计算各样本间的相似性系数和遗传距离,并采用UPGMA法对遗传距离进行了聚类分析。结果表明：中国水仙3个品种亲缘关系十分密切,红口水仙3个品种亲缘关系较近,而中国水仙与红口水仙3个品种间的亲缘关系较远。建立的水仙RAPD技术体系可帮助育种亲本的选配及水仙品种的鉴定。     

中国水仙遗传转化研究进展(综述)

中国水仙是我国传统名花,其栽培种一直存在三个问题：品种单一,繁殖速度有限,病毒积累严重。生物技术的发展为解决中国水仙目前存在的问题提供了新的途径。本文从外植体的预处理、愈伤组织和小鳞茎的诱导与分化、生根及移栽等方面概述中国水仙的组织培养进展,较详尽地阐述中国水仙基因工程的研究进展,并对中国水仙未来研究方向进行展望。     

自然光照下普陀水仙的组织培养

1　植物名称　水仙 (Narcissustazettavar.chi nensis)品种普陀水仙。2　材料类别　带鳞茎盘的双鳞片 (twinscale)。3　培养条件　以MS为基本培养基。 ( 1 )诱导小鳞茎培养基 :MS + 6 BA 5mg·L- 1 (单位下同 ) +NAA 0 .2 5～ 0 .5 ;( 2 )生根培养基 :1 /2MS(大量元素减半 ) +NAA 0 .0 5。培养基均加 0 .8%琼脂 (a gar) ,( 1 )加0 .5 %活性炭 (activatedcharcoal)和 4%蔗糖 (sucrose) ,( 2 )加 3%蔗糖 ,pH 5 .6～ 5 .8。培养温度 ( 2 5± 2 )℃ ,置于培养室自然光线下 ,不用灯光照明。4　生长与分化情况4.1　无菌材料的获得　 5、6月…     

昭通地区有野生水仙

水仙(Narcissus taretta var. chinensis)是石蒜科多年生草本植物,具鳞茎,夏季休眠,秋冬季展叶开花。原产地在地中海,我国栽培历史悠久,在福建、浙江沿海岸屿上已逸为野生。近年,我在云南昭通地区作植物考察时,发现在昭通大关县翠华镇、下高桥、木杆、悦乐、黄葛等地,海拔920米左右的西向坡和山沟坟地中都有水仙生长,同生植物有蔷薇、鸢尾、蒿属植物和多种蕨类。     

中国水仙(Narcissus tazetta var.chinensis)的组织培养

以栽培的中国水仙Narcissus tazetta var.Chinensis鳞茎为实验材料,采取“无液处理”的简捷方法获取外植体,并筛选出中国水仙离体鳞茎培养的最佳培养基。     

胞松素B对洋葱根尖细胞分裂及亚显微结构的影响

洋葱鳞茎被培养在含不同浓度胞松素B的自来水中时,根尖伸长的速度减慢,间期细胞的比例上升,前、中、后和末各期的细胞的比例相应下降。在超显微结构水平上,内质网和高尔基体小泡的内腔膨大,线粒体的结构和分布改变,细胞核表面突起或内陷,部分细胞器解体,文章讨论了胞松素B可能的作用机制。     

Embryological Studies on Narcissus tazetta var. chinensis

Chinese narcissus (Narcissus tazetta var.chinensis Roem) blooms but has no seeds.Embryological studies on the species were conducted to discover the causes of its sterility.Its anther wall is composed of four layers of cells,and its tapetum is of the secretory type.The cytokinesis of microspore mother cells is of the successive type,and the tetrad is tetrahedral.During meiosis of microspore mother cells,some chromosomes lagged,and several micronuclei were found in tetrads.Only 27.7% of the pollen grains contained full cytoplasm,and 1.3% of them germinated in culture medium.No pollen grain,however,could germinate on the stigma.The ovary is trilocular with axile placenta,and the ovules are bitegmic,tenuinucellate,and anatropous.Its embryo sac is of the polygonum type.Most embryo sacs degenerated,and only about 4.5% of the ovules contained a normal embryo sac with an egg cell,two synergids,three antipodal,and a central cell containing two polar nuclei.One reason for the sterility of Chinese narcissus is the abnormality of microsporogenesis and megasporogenesis,in which only a few functional pollen grains and embryo sacs are produced.The other reason is that the pollen grains cannot germinate on the stigma.     

Normalization of the DNA content of telophase cells from wheat calli by nutrient modifications

Summary Cytophotometric analyses were conducted to determine whether the DNA content of wheat callus varied by tissue culture medium or age of callus. Wheat,Triticum aestivum L. line PCYT-20, was cultured on three variations of the Murashige and Skoog (1962) growth medium. At the end of 2, 4, 6 and 8 weeks, samples were collected and prepared for Feulgen cytophotometry. Standards for the DNA measurements were readings from 100 telophase nuclei in wheat meristematic root tips. Amounts of DNA per nucleus present in telophase cells from callus grown on single-strength MS indicated that ploidy level increased 52%, 74% and 39%, respectively, over time from 2, 4, and 6 weeks as compared to the double-strength MS medium, and 29%, 60% and 32%, respectively, when coconut water was added to the single-strength MS culture medium. The shape of the mitotically-active cells in callus was more variable than in root tips cells. Callus grown on double-strength MS medium produced more shoots than callus grown on single-strength MS. Double-strength MS medium and, to a lesser extent, additional sucrose and organic nitrogen overcame the effects of 2,4-D on DNA amplification. Improved media may reduce the somaclonal variation induced by tissue culture.     

Embryological Studies on Narcissus tazetta var. chinensis

Chinese narcissus (Narcissus tazetta var. chinensis Roem) blooms but has no seeds. Embryological studies on the species were conducted to discover the causes of its sterility. Its anther wall is composed of four layers of cells, and its tapetum is of the secretory type. The cytokinesis of microspore mother cells is of the successive type, and the tetrad is tetrahedral. During meiosis of microspore mother cells, some chromosomes lagged, and several micronuclei were found in tetrads. Only 27.7% of the pollen grains contained full cytoplasm, and 1.3% of them germinated in culture medium. No pollen grain, however, could germinate on the stigma. The ovary is trilocular with axile placenta, and the ovules are bitegmic, tenuinucellate, and anatropous. Its embryo sac is of the polygonum type. Most embryo sacs degenerated, and only about 4.5% of the ovules contained a normal embryo sac with an egg cell, two synergids, three antipodal, and a central cell containing two polar nuclei. One reason for the sterility of Chinese narcissus is the abnormality of microsporogenesis and megasporogenesis, in which only a few functional pollen grains and embryo sacs are produced. The other reason is that the pollen grains cannot germinate on the stigma. This paper was translated from Journal of Xiamen University (Natural Science), 2005, 44(1) (in Chinese)     

Variation of B Chromosome Associated with Tissue Culture in Wheat-rye Cross

In vitro variation of B chromosomes was studied by examining the callus cells derived from the immature embryos from a cross of Chinese Spring wheat ( Triticum aestivum L.) and Fin 7416 rye ( Secale cereale L.) carrying two B chromosomes. In 40-d-old callus cells, the numbers of B chromosomes ranged from one to four in 65.6% of the cells observed. The distribution of B chromosome numbers was associated with the ploidy levels of the normal chromosomes (A chromosomes). The frequency of the cells with high numbers of B chromosomes (i.e., three or four B chromosomes) in the amphiploid cells with 56 A chromosomes was greater than those in the haploid cells with 28 A chromosomes. Although structural changes in the rye A chromosomes were observed, cytological observation and genomic in situ hybridization demonstrated that the rye B chromosomes were conserved in morphological appearance following tissue culture.     

百日草根尖和花药愈伤组织染色体制片技术

以种子萌发根尖和花药愈伤组织为材料,研究了取样时间、预处理方法对百日草染色体制片的影响。结果表明:根尖上午8:00～9:00,花药愈伤继代3～5d上午9:00～10:00为最佳取样预处理时间;采用三种药剂预处理活体根尖,以4℃下饱和对二氯苯溶液或0.002mol/L的8-羟基喹啉液预处理8h效果最佳,花药愈伤则以饱和对二氯苯溶液预处理6h效果最佳。本实验的预处理温度是固定的,可克服预处理随季节和时间温度的变化而带来的不稳定性,且百日草花药愈伤染色体观察为首次报道。     

Aneuploidy detection in porcine embryos using fluorescence in situ hybridization

In contrast to human embryos, there are very few studies published on the frequency of chromosomal aneuploidy in farm animals. The objectives of this study were to apply a three-color fluorescent in situ hybridization (FISH) method for evaluating aneuploidy in porcine embryos using chromosome-specific DNA probes, establish baseline frequencies of aneuploidy in embryos and compare the results with our previous findings of aneuploidy in spermatozoa and oocytes. The embryos were collected from superovulated gilts, which were slaughtered 48 h after insemination. FISH was performed using probes specific for the centromeric regions of porcine chromosomes 1, 10 and Y. Altogether 403 blastomeres from 114 porcine embryos were successfully investigated. Diploidy was observed in 101 (88.6%) embryos, triploidy in 2 (1.8%) embryos, mosaicism/mixoploidy in 9 (7.9%) embryos, and trisomy for chromosomes 1 or 10 in 2 (1.8%) embryos. No blastomere showed aneuploidy for chromosome Y. These findings correspond with the frequencies of aneuploidy we have found previously in porcine germ cells.     

Isolation of Chromosomes from Picea abies and their Analysis by Flow Cytometry

A high-yield method for preparation of suspensions of intact Norway spruce [Picea abies (L.) Karst.] chromosomes was developed for the first time. To accumulate meristem root tip cells at metaphase, actively growing roots were subjected to subsequent treatments with 0.625 mM hydroxyurea for 18 h and after 8 h recovery in distilled water with 0.05 % (m/v) colchicine for 8 h. These treatments resulted in 50 % metaphase indices. Synchronized root tips were fixed in 2 % formaldehyde for 10 min and chromosomes were released into a lysis buffer by mechanical homogenisation, producing 5 × 10⁵ chromosomes from 50 root tips, at average. The isolated chromosomes were morphologically intact and suitable for flow cytometric analysis. Flow karyotypes obtained after the analysis of DAPI-stained chromosomes indicated a possibility to sort at least three different chromosome types. This revised version was published online in July 2006 with corrections to the Cover Date.     

Mitotic and meiotic irregularities in somatic hybrids of Lycopersicon esculentum and Solanum tuberosum.

Chromosome numbers were determined in metaphase complements of root-tip meristems of 107 tomato (+) potato somatic hybrids, obtained from five different combinations of parental genotypes. Of these hybrids 79% were aneuploid, lacking one or two chromosomes in most cases. All four hybrids that were studied at mitotic anaphase of root tips showed laggards and bridges, the three aneuploids in a higher frequency than the single euploid. Hybrid K2H2-1C, which showed the highest percentage of aberrant anaphases, possessed 46 chromosomes. Fluorescence in situ hybridization with total genomic DNA showed that this hybrid contained 23 tomato, 22 potato, and 1 recombinant chromosome consisting of a tomato chromosome arm and a potato chromosome arm. The potato parent of K2H2-1C was aneusomatic in its root tips with a high frequency of monosomic and trisomic cells and a relatively high frequency of cells with one fragment or telosome. Meiotic analyses of three tomato (+) potato somatic hybrids revealed laggards, which occurred most frequently in the triploid hybrids, and bridges, which were frequently present in pollen mother cells (PMCs) at anaphase I of hypotetraploid K2H2-1C. We observed putative trivalents in PMCs at diakinesis and metaphase I of eutriploid A7-82A and quadrivalents in part of the PMCs of hypotetraploid K2H2-1C, suggesting that homoeologous recombination between tomato and potato chromosomes occurred in these hybrids. All three hybrids showed a high percentage of first division restitution, giving rise to unreduced gametes. However, shortly after the tetrad stage all microspores completely degenerated, resulting in exclusively sterile pollen.