Regeneration of adventitious shoots from mature stored cotyledons of Japanese plum (Prunus salicina Lind1)

Adventitious shoot regeneration from mature stored cotyledons of Japanese plum (Prunus salicina Lind1) was achieved in vitro. The influences of the presence and absence of the light, different concentrations of thidiazuron (TDZ) and benzyladenine (BA) in the culture media, TDZ pretreatments and different basal salts on shoot regeneration were evaluated. TDZ was more effective in inducing shoot regeneration from mature stored cotyledons than BA. Dark incubation significantly increased the regeneration frequencies. Quoirin/Lepoivre (QL) basal salts stimulated shoot regeneration more than woody plant (WPM) or B5 salts did. The frequency of adventitious shoot formation varied among the varieties and the regeneration ability appeared to be genotype depended. The frequency of regeneration under the optimum tested conditions for ‘Bruce’, ‘Shiro’, ‘Redheart’, ‘Gladstone’ and ‘Early Golden’ cotyledons were 66.7%, 46.7%, 43.3%, 26.7% and 6.7%, respectively.     

A SCAR marker linked to the N gene for resistance to root knot nematodes (Meloidogyne spp.) in pepper (Capsicum annuum L.)

The root-knot nematodes (Meloidogyne spp.) are important nematode pests and cause serious diseases in pepper in the world. No molecular markers linked to the nematodes resistance N gene have been reported. In this paper, ‘Carolina Wonder’ (Capsicum annuum L.), a sweet pepper line resistant to root-knot nematode with N gene, ‘20080-5-29’ (C. annuum L.), an inbred line susceptible to root-knot nematode with good horticultural characteristics, and their F₂ progeny with 320 individuals were used as materials. Evaluation of resistance and susceptibility of parental lines, F₁ and F₂ progeny inoculated with root-knot nematodes (Meloidogyne incognita) were carried out. ‘Bulked segregant analysis’ method was used to search for polymorphic markers from 512 pairs of AFLP primers. Based on the assessment of resistance and susceptibility and polymorphism of the AFLP marker in F₂ population, the genetic linkage distance between the AFLP marker and the N gene was estimated. One AFLP marker E39/M41-339 was obtained and transferred to a SCAR marker amplifying a 315 bp DNA fragment linked to the N resistant allele and a 331 bp fragment linked to the N⁺ susceptible allele. The distance between the molecular marker and the nematodes resistance N gene is 6.3 cM. This research delivered a valuable tool for the marker assisted selection of nematodes resistance in pepper.     

Characteristics of phosphorus uptake kinetics of poinsettia and marigold

In a previous experiment it has been found that maximum uptake rate (I_max), Michaelis constant (K_m), and minimum nutrient concentration (C_min) as plant physiological characteristics may be important for phosphorus (P) uptake in peat-substrate. Thus, variation of P uptake parameters was evaluated with a series of depletion studies for poinsettia (Euphorbia pulcherrima) and marigold (Tagetes patula) under fluctuating climatic conditions and different developmental stages.     

黄瓜耐弱光性的多元统计分析

 利用遮阳网模拟弱光条件, 调查18份黄瓜自交系苗期生长发育和生理生化指标, 采用多元统计分析方法评价黄瓜品系耐弱光性强弱。结果表明, 参试品系的13个指标在品系间存在显著差异, 利用因子分析将这些指标综合成5个主因子, 累计贡献率达85.62%。对旋转后的因子得分进行聚类分析, 供试品系可分为4类: 耐弱光材料M₂₂、M₄₃、M_a9; 较耐弱光材料M₈、M₁₁、M₃、M₄、M₃₄; 弱光中度敏感材料M₁₂、M₂₁、M₁₄、M₂、M_a1、M₂₈和弱光敏感材料M₁₀、M₄₄、M₃₂、M₃₆。经过弱光处理后耐弱光指数较大、光合速率降低幅度较小的品系耐弱光性强, 应结合耐弱光指数与光合、生长等因子综合进行黄瓜耐弱光性鉴定。     

利用抑制消减杂交技术分离辣椒细胞质雄性不育育性恢复相关EST

 以辣椒(Capsicum annuum L. ) 细胞质雄性不育系23A、121A, 和其相应的近等基因恢复系23C、121C为试验材料, 利用抑制消减杂交( SSH) 技术成功构建了CMS恢复基因诱导表达的消减cDNA文库。结合高密度点阵膜杂交差异筛选, 获得了282个阳性克隆。通过测序, 除去重复序列共得到175个Unique ESTs。在GenBank上进行BLAST分析, 55个EST片段未找到对应的同源序列, 可能代表了新基因;120个EST片段找到了对应的同源序列, 包括103个已知功能基因和17个未知功能基因。按照MIPS功能分类法, 将其分为14个功能组, 涉及代谢、胁迫应答、蛋白活性、转录因子、信号转导等多方面的功能。     

MdMYB1转录因子调控红星苹果果实着色的计算机模拟分析及表达验证

 从‘红星’苹果(Malus domestica‘Delicious’) 果实中克隆获得了MdMYB1基因, 通过生物信息学分析( in silico analysis) 和活体细胞融合蛋白荧光观察, 确定其编码蛋白定位于细胞核。同时, 克隆了MdDFR和MdUFGT基因的启动子, 模拟分析表明2个基因的启动子序列中含有MYB结合的顺式作用元件。为了探讨MdMYB1转录因子是否调控MdDFR和MdUFGT基因的表达, 对不同光照条件下果皮花青素含量和基因表达进行了检测, 结果表明光照能够诱导花青素积累, 并迅速启动3个基因表达, 且3个基因表现出高度相似的表达模式, 表明MdMYB1转录因子可能直接调控MdDFR和MdUFGT基因的表达。     

菠萝锌指蛋白基因AcRCHY1的克隆与表达分析

 根据植物C3HC4型兼CHY型锌指蛋白的功能保守区设计简并引物, 通过RT2PCR结合RACE 方法从菠萝(Ananas comosus L. Merr) 幼苗中克隆获得了一个新的菠萝锌指蛋白基因cDNA全长, 将其命名为AcRCHY1。该基因cDNA全长1 261 bp, 开放阅读框ORF为918 bp, 推测其编码一个含有306个氨基酸残基的多肽。AcRCHY1蛋白具有保守的C3HC4 (RING finger) 和CHY两个锌指结构域, 与其它植物锌指蛋白的同源性高达81%～91%。半定量RT-PCR分析表明, AcRCHY1 在菠萝中呈组成性表达, 在子房、花瓣和小花中的表达量明显高于根和叶; 低温、高盐、干旱和ABA等非生物胁迫处理后, AcRCHY1在叶片中的表达明显增强。因此, AcRCHY1蛋白可能与花器官生长发育的调控有关, 而且可能作为一个转录调控因子在菠萝响应低温、高盐和渗透胁迫过程中参与了依赖ABA的信号转导途径。     

DNA序列分析在植物分子系统学研究中的应用现状——-以蔷薇科为例

 近20年来, DNA序列已被广泛应用于植物各分类阶元的系统学研究中, 为解决长期有争议 的和亟待解决的系统进化问题提供了有力的证据。现以蔷薇科为例, 概述了应用DNA片段进行植物分子系统研究的现状, 详细剖析了应用DNA序列进行植物系统发育研究时常见的问题及其原因, 提出了对存在多倍化、杂交起源和快速分化等复杂进化史的植物类群进行系统学分析时选用DNA序列的策略和注意事项。     

白菜亚硝酸还原酶基因BcNiR的克隆及表达分析

 以白菜品种‘苏州青’自交系叶片cDNA为模板, 采用RT-PCR、3′RACE和5′RACE技术, 获得了编码亚硝酸还原酶基因(NiR) 的cDNA全序列1 852 bp, 包含有1 749 bp的开放阅读框, 编码583个氨基酸, 命名为BcNiR。所推导的氨基酸序列与拟南芥NiR1、烟草nii2编码的氨基酸序列具有较高同源性, 分别为83%和76%。生物信息学分析表明, BcNiR具有完整的NiR蛋白结构, 含血红素蛋白β - 化合物区域, 一个明显的西罗血红素siroheme结合位点和4Fe-4S区域, 可以在SWiSS-MODEL数据库中搜索到与之相近的三维结构。RT-PCR结果显示, 该基因在叶片中的表达量远远高于根系, 在以0、10、20、30、40 mmol·L ^{- 1}硝态氮各分别处理0、2、4、6、8、12 h的试验中, 30 mmol·L ^-1处理4 h可使BcNiR的表达量达到最大; 5和10 mmol·L ^{- 1}铵态氮处理试验表明, 高浓度的铵抑制该基因的表达。