川贝母多倍体诱导条件的优化及含量测定

采用正交试验法考察秋水仙素浓度、浸泡时间、二甲基亚砜体积分数、处理温度对川贝母(Fritillaria cirrhosa)愈伤组织多倍体诱导的影响.以多倍体诱导率为指标,用正交试验表L9(34)进行试验,筛选最佳诱导条件.在考察的因素中,对川贝母多倍体诱导率影响的大小次序依次为秋水仙素浓度＞浸泡时间＞二甲基亚砜体积分数＞处理温度.多倍体诱导条件的最优组合是秋水仙素浓度为900 mg/L、浸泡时间为48h、二甲基亚砜体积分数为4％、处理温度为20℃,在此条件下,其诱导率可达94.3％;细胞染色体鉴定结果为四倍体染色体数为2n=4x=48,诱导后的愈伤组织为多倍体;对野生、组培二倍体、组培多倍体川贝母鳞茎进行有效药用成分生物碱总含量测定,其中组培多倍体生物碱总含量最高为0.657％.     

Intravarietal polyploidy in the apple (Malus pumila Mill.) cultivar Hazratbali

Summary A triploid cytotype of cv. Hazratbali (Malus pumila Mill.), was found growing in orchards of diploid trees. Morphological comparisons between the two cytotypes reveal that the triploid is more vigorous, and bears more attractive fruit. The meiotic behaviour of the two cytotypes has been described. The impact of polyploidy on quality characteristics of apple at the intravarietal level is analysed. The possible mode of origin of the triploid cytotype is discussed.     

Chromosome Number Manipulation as Part of Potato Pre-breeding Programs

The cultivated potato(Solanum tuberosum L.) is a tetraploid(2n=4x=48) and can be improved with the incorporation of desirable traits from other Solanum species.Often the transfer of these traits is hindered by complex genetics and breeding barriers within potato.Parthenogenesis and microsporogenesis are used in chromosome number manipulation allowing breeders to reduce the potato's chromosome number to dihaploid(2n=2x=24)[diploid] or monohaploid(2n=x=12) from which a predictable transfer of traits can be made,in accordance with the endosperm balance number theory(EBN).Furthermore,the reproductive processes of first division restitution(FDR) and second division restitution(SDR) are utilized in order to increase the chromosome number for incorporation into the cultivated potato.     

朝鲜百合离体多倍体诱导

避光条件下,用0.10%秋水仙素附加2.00%二甲亚砜诱变离体培养的朝鲜百合小鳞茎,利用组织培养的不定芽诱导技术获得了多倍体幼苗,并对其根尖染色体数目进行常规鉴定。结果表明:诱导48h效果好,变异率达到50.00%。对照植株和得到的4个变异株系进行细胞学观察后发现,对照为二倍体(2n=2x=24),诱变出的4个变异株系细胞染色体数目分别由34~54条的不同比例构成,其中四倍体细胞染色体(2n=4x=48)占38.18%~76.47%,属于嵌合体。     

紫穗槐多倍体的诱导条件优化

用秋水仙素对植物进行多倍体诱导是人工诱导的方法之一,为了探究诱导紫穗槐多倍体的最优化条件,选取秋水仙碱,根长以及光照情况3个影响因素,对紫穗槐根尖进行涂抹处理诱导多倍体。并对其形态学和细胞学的2个方面进行观察分析。由正交试验结果表明,秋水仙碱浓度为0.1%、根长为0.8-1.5㎝、半光照的条件下,其诱导率最高。     

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。     

Enhanced productivity of the essential oil in the artificial autopolyploid of vetiver (Vetiveria zizanioides L. Nash)

Summary Artificial autotetraploids were produced by colchicine treatment in the important essential oil bearing vetiver (2n=20). The raw tetraploids were stabilised by selection for pure types in segregating vegetative progeny. The tetraploids were vigorous with thicker and longer roots. The performance data recorded on 17 months' old crop of the tetraploid taken in conjunction with diploid parent and the best available check, exhibited distinct superiority of the tetraploid. In terms of economic yield the tetraploid has the potential of producing 62.5% and 39.2% more oil over the diploid parent and the check, respectively. Although there was marginal improvement in root biomass but significant improvement was registered for percent oil content. The tetraploid produced 1.4% oil in freshly harvested roots compared to 0.98% and 1.15% in the control and check respectively. The study explicitly demonstrate the use of induced tetraploidy in attaining rapid genetic improment even for the characters associated with the secondary metabolism.This paper is dedicated to Professor AK Sharma to commemorate his 40 years association with chromosome research, (CIMAP Publication No. 719).     

A technique for identifying polyploid sectors in grass inflorescences

Summary A simple technique for counting mitotic chromosome numbers in ovaries of inflorescences has been developed and applied to grasses. The uses, as outlined, include isolating polyploid inflorescences for hybridization, and as an alternative method to root-tip squashes for chromosome morphology and banding studies.     

A strict diploid-like pairing regime is associated with tetrasomic segregation in induced autotetraploids of kale

Fertility and reproductive stability in polyploids depend on the precise control of chromosome pairing at meiosis. In this study, meiotic pairing configurations are related to isozyme segregation ratios in F₁ hybrids between colchicine‐induced autotetraploids of kale. An immediate diploid‐like pairing regime is associated with tetrasomic segregation. Although the mechanisms driving such a behaviour have yet to be identified, pairing preferences are not responsible for the cytological diploidization of autotetraploid kales.     

Survival of Diploid and Triploid Rhamdia quelen Juveniles Under Different Oxygen Concentrations

The objective of this study was to determinate the lethal concentration of dissolved oxygen (DO) over 96 hours of exposure (LC50–96h) for diploid and triploid jundia Rhamdia quelen juveniles. Diploid and triploid fish weighing approximately 4 g were subjected to DO concentrations varying between 0.4 and 1.3 mg O₂ L^?1; water temperature was maintained at 27?°C and pH at 6.3. The LC50–96h for diploids of Rhamdia quelen was 0.535 mg O₂ L^?1, while the value obtained for triploids was 6% greater. These results demonstrated that triploids of Rhamdia quelen juveniles have greater sensitivity to hypoxia compared to diploids.