百合多倍体的研究进展

我国具有丰富的百合种质资源,其多倍体广泛应用于生产与育种研究。通过查阅国内外大量相关的文献,阐述丁百合育种的目标和现状,简要介绍多倍体的诱导方法,百合多倍体的特征特性及其在观赏与食用上的应用。重点介绍了多倍体诱导在百合育种中的应用以及百合二倍体体细胞无性系的建立,并指出育种中存在的问题及对未来育种前景的展望。     

Regeneration of symmetrical hindlimbs in larval salamanders

The complete circle rule of the polar coordinate model of pattern regulation was tested for regenerating hindlimbs of Ambystoma larvae. The hindlimbs were made symmetrical in the circumference of either the thigh or the shank, and their ability to regenerate from both levels was observed. Thighs composed of two anterior halves failed to regenerate, whereas thighs composed of two posterior halves often regenerated distally complete, correspondingly symmetrical limbs; shanks composed of either two anterior or two posterior halves regenerated distally complete, correspondingly symmetrical limbs. These results are in contrast to what is predicted by the complete circle rule and suggest a modification of this rule.     

观赏植物多倍体诱导研究进展

文章对园艺植物多倍体的特点及其应用进行了简介,列出了近三十年成功诱导多倍体的主要观赏植物种类,对观赏植物多倍体诱导中诱变材料和诱变剂种类的选择,主要诱导方法中的化学诱变结合组织培养法、胚乳培养法、原生质体融合法、2n配子法等,主要鉴定方法中的染色体计数法、形态性状和生长发育观察法、生理指标测定法、细胞水平和分子水平分析法等进行了综述和分析,并对多倍体诱导中存在的嵌合体筛选、多倍体低稔性等主要问题进行了讨论,以期为今后观赏植物多倍体育种提供参考。     

桑树多倍体育种的回顾与展望

本文简述了国内外桑多倍体育种的历史与现状,以及多倍体特别是三、四倍体的特征特性和经济价值。我国迄今发现有天然三倍体６４份,四倍体１３份,六倍体６６份,八倍体２份和二十二倍体１份,是桑多倍体资源最丰富的国家。近年我国桑多倍体育种研究,在无性及实生上倍体诱导技术,三倍体培育及多倍体为亲本的杂优组合选配技术等方面进展很快,已培育出一批表现较好的人工三倍体及以多倍体为亲本的杂优组合。还提出了多倍体育种今后     

结球甘蓝同源多倍体的诱导及鉴定

以结球甘蓝自交系‘0501’为材料进行了多倍体的诱导和鉴定研究。结果表明:用蘸0.1%秋水仙素药液的脱脂棉小球处理籽苗生长点24~72h均可有效地诱导细胞染色体加倍,其中24h的诱变效果最好,四倍体株率为77.78%;四倍体植株长势良好,花蕾、花冠、花粉粒、保卫细胞、叶片、等器官和细胞都明显比二倍体植株的大;叶绿体数随倍性提高(2x、4x、8x)而提高;气孔密度、叶片长宽比和花瓣长宽比随倍性增加而减小;四倍体植株的减数分裂行为较二倍体的复杂,终变期和中期Ⅰ可见四价体、三价体、二价体和单价体等联会形式;后期Ⅰ,同源染色体大多呈2/2分离,偶见落后染色体,分到两极的染色体数主要为18/18和17/19,各占68.57%和24.29%;四倍体植株的花粉量充足,花粉生活力达87.27%;四倍体植株的DNA相对含量是其二倍体的2倍,Vc、粗蛋白及含糖量较其二倍体均有所提高。     

Natural triploidy in salamanders related to Ambystoma jeffersonianum

Female salamanders with large erythrocytes and erythrocyte nuclei produced triploid larvae; females with small erythrocytes and erythrocyte nuclei produced diploid larvae. Larval chromosome counts, dimorphism in cell size, and sex inheritance indicate distinct, persisting populations of triploid females in parts of the range of the Ambystoma jeffersonianum complex.     

Autogamy of polyploid apple varieties and forms

Long-term study of triploid varieties obtained from crossing of diploid varieties and forms with tetraploid ones has resulted in showing their high autogamy. In the case of natural self-pollination of the Rozhdestvenskoe triploid variety, the fruit yield was 12.6%, and that in the case of its cross-pollination with other varieties averaged only 9.55; in the Avgust triploid variety, the fruit yield was 4.4 and 2.8%, respectively. The high autogamy of tetraploid varieties and forms is evidenced by the following data: their crossing with diploid varieties (4x × 2x) yielded 4003 one-year seedlings, of which approximately 15% proved to be tetraploid.     

我国鱼类多倍体育种的研究进展

鱼类多倍体育种属于“染色体组工程”(genome engineering)的范畴,因其具有控制性别的潜力,已引起了生物学家、鱼类育种学家的浓厚兴趣和深入探索。由于三倍体在生长优势、群体产量及抗病力等各方面都有二倍体所无法比拟的优势,因此多倍体育种研究对水产养殖具有重大的意义。     

葡萄多倍体诱导及其特征特性研究

通过葡萄的离体培养,对多倍体葡萄诱导及其特征特性进行了研究,结果表明,秋水仙素加入培养基中诱导葡萄多倍体,以20 mg／L秋水仙素加入附加有0．01 mg／L 6-BA的MS培养基中包埋腋芽诱导染色体加倍效果较好。不同品种对秋水仙素的敏感反应不一,以红提为亲本诱导获得染色体加倍率分别为66．1％、64．6％的诱变株系 H0120-1和H0120-3。诱变株与原二倍体红提比较,具有多倍体的部分特征特性;诱变株与原二倍体红提气孔平均大小、气孔指数无明显差异,但诱变株存在20．8％的特大气孔。     

Extraoptic phase shifting of circadian locomotor rhythm in salamanders

Timing of locomotor rhythm in the slimy ralamander, Plethodon glutinosus, can be shifted in phase by the environmental light cycle, whether the animals have eyes or not. Rhythmicity persists at least for the first day when animals are transferred to constant conditions, with a period of about 24 hours, and is therefore circadian in nature. An extraoptic photoreceptor site in the brain is suggested.     

Morphological novelty in the limb skeleton accompanies miniaturization in salamanders

Salamanders of the genus Thorius (Plethodontidae) are among the smallest tetrapods. Hypotheses of limb skeletal evolution in these vertebrates were evaluated on the basis of estimates of natural variation, comparisons of skeletal homology, and analysis of molecular phylogeny. Nine carpal arrangements occur in Thorius, more than in all twelve related genera of typically larger salamanders; six of these arrangements are unique. They represent a trend toward a decrease in the number of separate cartilages that is independent of locomotor and ecological specialization. Miniaturization may be an important source of morphological novelty, distinct from local adaptation, in vertebrates.     

我国鱼类多倍体育种的研究进展

鱼类多倍体育种属于“染色体组工程”(genome engineering)的范畴，因其具有控制性别的潜力，已引起了生物学家、鱼类育种学家的浓厚兴趣和深入探索。由于三倍体在生长优势、群体产量及抗病力等各方面都有二倍体所无法比拟的优势，因此多倍体育种研究对水产养殖具有重大的意义。     

半支莲多倍体诱导的初步研究及鉴定

采用不同浓度的秋水仙素溶液对半支莲植株不同部位组织进行诱变处理,并采用不同的方法对变异株进行鉴定。结果表明,对半支莲萌动种子,0.05%秋水仙素处理12h的变异率最大、为11%;对茎尖生长点,0.10%秋水仙素处理48h的变异率最大、为75%;对根尖,采用4%二甲亚砜与0.05%秋水仙素混合溶液处理8h和16h的变异率最大、为16.7%。可见,秋水仙素诱导半支莲茎尖的效果最好,其次为改良浸根法,萌动种子效果较差。形态学鉴定结果发现,变异株叶片明显变短、变宽,叶色浓绿,花径变大;解剖学鉴定结果表明,变异株气孔长度和宽度明显大于对照株,气孔数少于对照株,花粉直径也明显增大;分子生物学鉴定结果表明,采用流式细胞仪对初选的13株拟多倍体进行DNA含量分析,有11株产生了多倍体变异,总变异率达84.6%,其中四倍体7株、八倍体3株、嵌合体1株。     

林木多倍体育种研究进展

该文综述了林木多倍体育种的途径、方法及其应用现状 ,指出多倍体育种在速生、优质、高抗逆性等林木新品种选育中具有更大的潜力 ;目前在林业生产中应用的多倍体新品种数量之所以相对较少 ,主要与树木细胞遗传等基础研究滞后、一些多倍体育种相关理论和技术难题未能得以攻克有关 .而随着人类对其应用价值认识的提高以及有关新技术方法的注入 ,建立在现代遗传学以及细胞染色体工程技术基础之上的林木多倍体育种将焕发出新的生机与活力 .     

石刁柏多倍体的诱导与鉴定

以石刁柏品种UC800为材料,以秋水仙素为诱变剂,用浸泡法和涂抹法处理石刁柏试管苗,进行多倍体诱导.结果表明:以0.10%秋水仙素为诱变剂,用涂抹法处理72 h的效果较佳,形态学分析显示其加倍率可达94%;对多倍体材料进行染色体鉴定,涂抹法染色体加倍效果(细胞加倍率96.1%)也优于浸泡法(细胞加倍率86.4%).     

多倍体金线莲一次性成苗及移栽

筛选多倍体金线莲一次性成苗的最佳培养基配方并探讨不同基质对移栽苗生长的影响.结果表明:MS+1.0 mg·L-16-BA+1.5 mg·L-1NAA+150 g·L-1土豆+3%蔗糖+0.65%琼脂+0.15%活性炭为最佳一次性成苗培养基配方;经120 d培养即可获得生长、生根同步完成的组培瓶苗,具有长势一致(株高5~7 cm),茎节多且粗(茎粗1.19 cm),根系发达(每株2~3条根)等优势;最佳移栽基质为:泥炭土∶碎松树皮=1∶1(体积比),移栽苗成活率(92%)最高,长势最好,植株增高(1.53 cm)、增重(0.43 g)均达到最大,折干率(13.31%)相对较高.     

秋水仙素诱导细叶百合多倍体研究

为获得具有优良观赏性状和农艺性状的细叶百合四倍体植株,并为百合的新品种选育提供性状优良的杂交亲本,以细叶百合种子(2n=2x=24)为试验材料,通过秋水仙素浸泡种子的方法,研究了不同秋水仙素浓度和处理时间对细叶百合染色体加倍的诱导效果.结果表明:以0.1％秋水仙素处理24 h诱导效果最佳,变异率最高,达30％.经根尖染色体鉴定,四倍体植株染色体数目为2n=4x=48.四倍体植株气孔密度减少,气孔增大;前期生长势缓慢,叶片短缩增宽,叶色加深;后期生长健壮,叶片增大明显.通过对经秋水仙素诱导获得的变异植株形态、气孔的观察测定以及染色体倍性鉴定,成功获得了细叶百合的多倍体植株.     

Hylid frogs: polyploid classes of DNA in liver nuclei

Microspectrophotometric DNA determinations on liver nuclei of hylid frogs have revealed the presence of several polyploid classes of DNA in several specimens belonging to five species. All such specimens were breeding.