Analysis of DNA methylation patterns of PLBs derived from <Emphasis Type="Italic">Cymbidium hybridium</Emphasis> based on MSAP

The best known and most thoroughly studied epigenetic phenomenon is DNA methylation, which plays an important role in regulating gene expression during plant regeneration and development. In this study, the methylation-sensitive amplified polymorphism (MSAP) technique was carried out to determine differences in methylation profiles between two forms of protocorm-like bodies (PLBs), continuously proliferating PLBs (cPLBs) and spontaneously-differenting PLBs (sdPLBs), derived from cultures of Cymbidium hybridium. A total of 72 selective primer combinations were used to assess the status of cytosine methylation of DNA in these tissues. Of 4,440 fragments obtained 911 fragments, each representing a recognition site cleaved by one or both of the isoschizomers (Hpa II and Msp I), were amplified and were significantly different between the two forms of PLBs. Frequency of total and full-methylation of cPLBs and sdPLBs were 26.7/12.2%, 24.1/11.1%, respectively. In addition, 14 types of MSAP patterns detected in the two forms of PLBs belonged to two classes, type I and II. Sequencing of 14 differentially methylated fragments and their subsequent blast search revealed that cytosine methylated 5′-CCGG-3′ sequences were equally distributed in the coding and non-coding regions. Southern blotting was conducted to verify the methylation polymorphism.     

寒兰的快速繁殖技术

以寒兰(CymbidiumkanranMakino)根状茎为外植体,采用B5基本培养基,并附加不同浓度的6-BA、NAA、TDZ(苯基噻二唑基脲-thidiazuron)和S-3307(优康唑-uniconazole),对类原球茎的诱导、继代增殖、分化、生根等进行研究。结果表明:诱导类原球茎的最佳培养基为B5 TDZ0.50mgL-1 NAA0.25mgL-1,诱导率98.3%;继代增殖的最佳培养基为B5 S-33071.0mgL-1 NAA0.2mgL-1 蔗糖3.5%,增殖系数9.4;类原球茎分化的最佳培养基为B5 S-33070.75mgL-1 6-BA1.0mgL-1 NAA0.4mgL-1,分化率87.8%;最佳的生根培养基为1/2B5 NAA0.2mgL-1 活性炭0.05%,生根率达100%。     

病毒唑对大花蕙兰CyMV及ORSV脱毒效果初探

在大花蕙兰茎尖培养中结合病毒唑处理,探讨对建兰花叶病毒(CyMV)和齿兰环斑病毒(ORSV)的脱除效果。结果表明,病毒唑添加到培养基中,处理茎尖2周,脱毒效果低于经病毒唑处理3个月后的幼苗,经病毒唑处理幼苗再结合茎尖培养脱毒效果最好。病毒唑处理对大花蕙兰CyMV的脱除效果优于对ORSV的脱除效果。     

兰属种间杂交胚拯救研究初报

取兰属大花蕙兰为母本、墨兰为父本进行种间杂交并进行杂种胚拯救研究。结果显示,子房离体培养明显优于胚珠离体培养,是胚抢救培养的有效手段。不同取材时间及在不同培养基中子房培养情况差异明显。在授粉后60 d子房离体培养即可获得成功,但以授粉后90 d子房离体培养最佳,萌发率高,达80%。子房培养的最适培养基为VW+BA 0.2 mg/L+NAA 0.2 mg/L+蛋白胨3 g/L+水解酪蛋白500 mg/L+椰子汁10%。     

春兰CgSEP3基因的克隆和表达分析

该研究采用RT-PCR和RACE技术从春兰(Cymbidium goeringii)中分离到1个SEPALLATA3(SEP3)基因。序列分析表明,该基因含有1个732bp的开放阅读框(ORF),共编码243个氨基酸。系统进化树分析显示,该基因是MADS-box基因家族AP1/AGL9组SEP的同源基因,其编码蛋白与其它植物SEP3类蛋白具有较高的一致性,命名为CgSEP3(登录号为KF924272)。实时荧光定量分析表明,CgSEP3在春兰花器官中均有表达,其中在唇瓣、侧瓣和萼片中的表达量较高,在子房和蕊柱中的表达量较低;而且CgSEP3在花发育各个时期都有表达,在1~2cm的花芽中表达量最高,在盛开的花中的表达量最低。研究认为,CgSEP3基因可能在春兰花瓣和萼片的形成过程中具有重要作用。     

Cymbidium quinquelobum,A New Species of Orchidaceae from Yunnan

Cymbidium quinquelobum, a new orchid from Yunnan, is described and illustrated. It is akin to Cymbidium wenshanense Y. S. Wu et F. Y. Liu, from which it differs by having a 5- lobed lip that is fused at base to the basal margins of the column forming a tube 8- 10 mm long .     

建兰规模化生产体系规范化探讨

对建兰规模化生产体系,包括园区建设、繁殖与栽培、日常管理、病虫害防治等主要环节进行规范化探讨,以期为建兰商品化生产提供参考。     

大花蕙兰的栽培管理技术

本文从大花蕙兰生长所需的生态环境、营养基质及组培苗特性等方面,对大花蕙兰的栽培技术进行讨论,并提出组培苗各发育阶段的栽培措施。     

几种植物生长调节物质对大花蕙兰组培原球茎增殖的影响

采用KC 培养基, 分别添加不同浓度的BA、KT、NAA 及KT+NAA 组合, 对大花蕙兰初代培养已分化出的原球茎进行了继代培养。结果发现:①BA 可加快原球茎的增殖速度, 但浓度超过0.5 mg/L 后增殖速度有所下降, 且原球茎变小呈暗绿色。②KT 的促进增殖效果好于BA, 但浓度超过1.0 mg/L 时, 增殖速度也有所下降, 原球茎变小。③NAA 促进原球茎增殖的效果明显好于BA、和KT, 但浓度大于1.0 mg/L 后增殖不再加快, 而且部分原球茎有变褐现象。④在KT 0.5~0.7 mg+NAA 0.7~1.0 mg/L 范围组合的KC 培养基上, 大花蕙兰原球茎增殖的速度和质量是比较理想的。考虑到较低的细胞分裂素和植物生长素有利于植物增殖过程中遗传性的稳定, 选择KT0.5 mg+NAA 0.7 mg/L 的KC 培养基作为大花蕙兰原球茎增殖培养基。