Direct gene transfer into Actinidia deliciosa protoplasts: analysis of transient expression of the CAT gene using TLC autoradiography and a GC-MS-based method

Chloramphenicol acetyl transferase (CAT) gene was used as a reporter gene to assess the conditions for polyethylene glycol (PEG)-mediated transfection of kiwifruit protoplasts. The effect of plasmid concentration and the presence of carrier DNA were each assessed by analysing CAT activity in transfected protoplasts using thin-layer chromatography (TLC) autoradiographic detection of acetylated chloramphenicol. A gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) non-radioactive method was developed for monitoring CAT gene activity. This method provides a high speed of analysis (30 min) and precise means of detecting acetylated products at the nanomolar level, enabling quantification at very low transfection rates. Using this method we optimized plasmid and PEG concentration and also assessed the effect of heat shock on transfection. The best CAT activity was obtained using 30% polyethylene glycol 4000 and by submitting protoplasts to heat shock (45 °C, 5 min) prior to transfection.     

Kiwifruit micropropagation through callus shoot-bud induction

Summary A profitable system for the establishment of morphogenic callus cultures and indirect shoot induction and development was accomplished from nodal shoot segments obtained from adult and micropropagated plants of kiwifruit (Actinidia deliciosa [Chev.] Liang and Ferguson, var.deliciosa) cv. “Hayward”. The effects of medium composition, cytokinin levels, dilution of salts, and type of callus derived from the cultured primary explants were studied. Medium composition as well as type of callus greatly affected organogenic responses.     

中华猕猴桃和美味猕猴桃的倍性变异及地理分布研究

根据已有的猕猴桃自然地理分布资料,通过对中华猕猴桃（Actinidia chinensis）和美味猕猴桃（A．deliciosa）野外分布居群的详细调查,利用流式细胞技术对我国西部高原台地向中东部丘陵平原过渡地带6个纯中华猕猴桃、1个纯美味猕猴桃和5个中华／美味猕猴桃同域分布居群共276个个体的倍性进行了检测。结果表明：（1）中华猕猴桃存在二倍体和四倍体,美味猕猴桃存在四倍体、五倍体和六倍体;（2）中华猕猴桃和美昧猕猴桃在经度和纬度的分布上存在显著差异（P〈0．05）,中华猕猴桃在经度上偏东分布而美味猕猴桃偏西,纬度分布上中华猕猴桃偏南而美味猕猴桃偏北;而且不同倍性小种在经、纬度分布上呈现显著差异（P〈0．05）,二倍体、四倍体、六倍体的分布在经度上依次从东到西、纬度上从南到北;（3）中华猕猴桃和美味猕猴桃不同倍性小种的海拔分布存在显著性差异（P〈0．05）,二倍体小种分布海拔最低,四倍体小种次之,六倍体小种海拔分布最高,但通过LSD分析四倍体个体和六倍体个体在海拔分布上不存在显著差异（P〉0．05）。通过对中华／美味猕猴桃这两种具有重要经济价值的果树的倍性变异及地理分布的探讨,提出了猕猴桃倍性小种分布的上述规律并给猕猴桃种质资源收集、评价、创新和可持续利用方面提供了初步的研究基础,尤其是为我国猕猴桃新品种选育提供了基础数据和科学依据。     

自然越冬期软枣猕猴桃枝条组织结构及内源激素的变化特征

该试验以抗寒性不同的5年生软枣猕猴桃品种‘魁绿’、‘丰绿’和‘96-6’为试验材料,测定分析自然越冬期间枝条组织解剖结构、细胞膜透性和内源激素GA3、ABA、IAA含量水平的变化,以明确不同品种软枣猕猴桃越冬期间对低温的适应能力及其内在生理机制,为软枣猕猴桃抗寒品种的选育及鉴别提供理论依据。结果表明:(1)软枣猕猴桃枝条木质部比率大小依次为‘魁绿’>‘96-6’>‘丰绿’,皮层比率依次为‘丰绿’>96-6’>魁绿’,二者表现趋势相反,且‘魁绿’枝条的解剖结构与其他两品种差异显著。(2)在自然越冬期间,各品种软枣猕猴桃枝条相对电导率和MDA含量随温度变化均呈先升后降的趋势,在温度最低的1月份达到最高,其中‘魁绿’枝条的相对电导率和MDA含量变化幅度最小,而‘丰绿’受低温影响较大。(3)在11月份至2月份,随自然温度的变化,各品种软枣猕猴桃枝条的GA3和IAA含量均呈先降低后升高的变化趋势,ABA含量则呈先升后降的趋势,且都在1月份分别达到最低或最高值。研究发现,在自然越冬期间,低温对3个软枣猕猴桃品种的组织解剖结构、膜透性及内源激素含量均都造成较大的影响,品种‘魁绿’枝条的木质部比率最大、皮层比率最小,相对电导率和MDA含量变化幅度最小,内源激素含量GA3和ABA/GA3变化趋势较小,故其抗寒性比‘丰绿’和‘96-6’更强。     

Actinidia arguta Pulp: Phytochemical Composition,Radical Scavenging Activity,and in Vitro Cells Effects

Hardy kiwifruit (Actinidia arguta) is a highly appreciated exotic fruit endowed with outstanding bioactive compounds. The present work proposes to characterize the pulp from A. arguta organic fruits, emphasizing its radicals scavenging capacity and effects on intestinal cells (Caco-2 and HT29-MTX). The physicochemical properties and phenolic profile were also screened. The total phenolic and flavonoid contents (TPC and TFC, respectively) of pulp were 12.21 mg GAE/g on dry weight (DW) and 5.92 mg CE/g DW, respectively. A high antioxidant activity was observed (FRAP: 151.41 μmol FSE/g DW; DPPH: 12.17 mg TE/g DW). Furthermore, the pulp did not induce a toxic effect on Caco-2 and HT29-MTX cells viability up to 1000 μg/mL. Regarding in vitro scavenging capacity, the pulp revealed the highest scavenging power against NO^. (IC₅₀=3.45 μg/mL) and HOCl (IC₅₀=12.77 μg/mL). These results emphasize the richness of A. arguta fruit pulp to be used in different food products.     

几种猕猴桃种间杂交亲和性的探讨

以中华猕猴桃、毛花猕猴桃、美味猕猴桃及阔叶猕猴桃进行种间杂交,结果表明:各杂交组合的座果率与对照组一样,均为100％;父本花粉萌发率与对照组相近,其杂交当代果实重量、种子数量及种子千粒重也与对照组相近;相同的母本,其当代杂交果实的重量及种子数量与父本花粉萌发率的高低成正比。这不但说明了各杂交组合所采用亲本之间的亲和性,而且为生产上利用不同种生活力强的猕猴桃雄株花粉进行人工辅助授粉提供依据。     

广西猕猴桃发展的策略分析

分析了广西猕猴桃发展的有利条件和现状, 并提出了相应的发展策略, 可供各级领导和有关生产单位参考, 对促进广西猕猴桃进一步发展具有指导意义。     

Cytotoxic Triterpenoids from Roots of Actinidia chinensis

Phytochmical investigation of roots of Actinidia chinensisPlanch . led to the isolation triterpenoids 1 – 16 , including a new compound 2α,3α,23,24‐tetrahydroxyursa‐12,20(30)‐dien‐28‐oic acid ( 1 ). Their structures were identified on the basis of spectroscopic analysis, including 1D‐ and 2D‐NMR, HR‐ESI mass spectrometry, and by comparison with the literatures. The cytotoxicities of triterpenoids 1 – 16 against a panel of cultured human cancer cell lines (HepG2, A549, MCF‐7, SK‐OV‐3, and HeLa) were evaluated. The new compound 1 exhibited moderate antitumor activities with IC₅₀ values of 19.62 ± 0.81, 18.86 ± 1.56, 45.94 ± 3.62, 62.41 ± 2.29, and 28.74 ± 1.07 μm , respectively. The experiment data might be available to explain the use of roots of A. chinensis to treat various cancers in traditional Chinese medicine.     

猕猴桃RNA提取与RT-PCR

为了从富含多糖和多酚等物质的猕猴桃幼叶中提取和分离出高质量的RNA,用多个不同品种的猕猴桃叶为材料,比较了3种不同的RNA提取方法所提取的总RNA。结果表明,用胍-酚酸-DEPC法提取的RNA质量最好,提取率达到682.9~780.8μg?g(FW),其R值(A260?A280)接近1.90。用所提取的RNA样品进行RT-PCR,其扩增产物在琼脂糖凝胶上出现明显清晰的扩增cDNA带,说明RNA样品在纯度和浓度上都可以满足PCR等分子生物学实验的基本要求。