马铃薯茎尖超低温保存流程TTC活力响应

以马铃薯栽培种呼自83-213无菌试管苗茎尖为材料,通过开展2,3,5-氯化三苯基四氮唑(TTC,2,3,5-Triphenyl tetrazolium chloride)茎尖活力染色关键因素研究,优化了马铃薯茎尖TTC活力染色条件,确定了适合的染色温度为40℃,染色时间为2 h。利用优化的TTC活力染色条件,对马铃薯茎尖小滴玻璃化超低温保存关键步骤处理茎尖进行TTC活力观察。研究发现:经蔗糖预培养(MS培养液添加0.3 mol/L和0.5 mol/L蔗糖)的茎尖与新鲜茎尖均保持高活力;经PVS2处理后茎尖表现时空特异性活力丧失和存活,分生组织和叶原基中间区域仍保持较高活力。通过对茎尖TTC活力染色面积测定,发现当茎尖TTC活力染色面积比≥0.4时,TTC活力染色与恢复培养存活率呈极显著正相关。     

茎尖和芽的超低温保存

介绍了植物茎尖和芽超低温保存的意义和现状。影响超低温保存的一些主要因素及其所采取的措施,主要包括预培养、低温锻炼、使用冰冻保护剂以及适当采用不同的降温方法和化冻洗涤方法,并就今后的研究提出了一些看法。     

猕猴桃茎尖超低温保存过程中超微结构观察

应用透射电镜观察了猕猴桃组培苗茎尖细胞在玻璃化法超低温保存过程中的超微结构变化.研究发现:在预培养、PVS2脱水处理过程中,茎尖细胞内液泡逐渐变多、变小,质壁分离愈加显著,表明细胞的抗冻力增强;在随后的冷冻和解冻过程中,部分细胞的质壁分离更加严重,细胞壁与细胞膜之间出现液腔,细胞器变得模糊,有些细胞的细胞膜、甚至细胞壁撕裂,细胞腔内留下破碎的细胞膜和细胞残片,细胞结构破坏严重,这可能是导致材料在恢复培养中死亡的原因之一;部分细胞经过7d的恢复培养后,细胞器清晰,细胞膜完好并紧贴细胞壁,细胞中央出现较大的液胞,具有与对照相似的结构特征,最终存活下来并能够再生植株.     

玻璃化法超低温保存蛇莓茎尖

本文采用玻璃化法对蛇莓离体茎尖超低温保存进行了初步探讨。研究了低温锻炼时间、预培养时间、预处理时间、玻璃化液处理时间和液氮保存时间对超低温保存后成活率的影响。经优化,蛇莓的最高成活率可达（42.00±2.74）%。     

香蕉茎尖超低温保存过程中的细胞超微结构观察(简报)

超低温保存(Cryopreservation)通常称为液氮保存或LN(-196℃)保存,是目前植物种质资源长期稳定保存的理想方法,已经成功应用于多种植物种质资源保存。玻璃化法(Vitrification)超低温保存植物种质资源始于20世纪80年代末,Uagami等首次     

扶芳藤茎尖的玻璃化法超低温保存及其植株再生

扶芳藤属卫矛科卫矛属常绿藤本灌木,我国拥有丰富的扶芳藤资源,目前已经引起了专家学者的注意,扶芳藤的资源和变异研究(潘青华等2004)、叶片粗蛋白和氨基酸成分分析(潘青华等     

拟南芥幼苗超低温保存后DNA甲基化的遗传变异

运用MSAP技术分析了拟南芥(Arabidopsis thaliana)幼苗超低温保存后DNA甲基化的遗传变异情况。结果表明, 在扩增的662条带中, 对照和2个处理及其第2代间完全一致的带型有598条; 发生变化的带型有64条, 其中能遗传给第2代的有48条, 占变异条带的75%。与对照相比, 经超低温保存的样品新产生的甲基化位点有14个, 而去甲基化的位点有22个。经过处理但未冷冻的与冷冻处理组之间带型一致的有624条, 差异条带有38条, 占5.7%, 而对照与未冷冻处理组的差异率是7.45%, 对照与冷冻处理组之间的差异率是6.63%。可见, 拟南芥在超低温保存中, 无论是经液氮冷冻还是未经冷冻处理, 对材料的甲基化状态均有影响, 而这种甲基化变化大部分是可以遗传的。     

拟南芥幼苗超低温保存后DNA甲基化的遗传变异

运用MSAP技术分析了拟南芥（Arabidopsis thaliana）幼苗超低温保存后DNA甲基化的遗传变异情况。结果表明,在扩增的662条带中,对照和2个处理及其第2代间完全一致的带型有598条：发生变化的带型有64条,其中能遗传给第2代的有48条,占变异条带的75％。与对照相比,经超低温保存的样品新产生的甲基化位点有14个,而去甲基化的位点有22个。经过处理但未冷冻的与冷冻处理组之间带型一致的有624条,差异条带有38条,占5.7％,而对照与未冷冻处理组的差异率是7．45％,对照与冷冻处理组之间的差异率是6。63％。可见,拟南芥在超低温保存中,无论是经液氮冷冻还是未经冷冻处理,对材料的甲基化状态均有影响,而这种甲基化变化大部分是可以遗传的。     

红豆草组织培养物的超低温保存及其超微结构的观察

红豆草(Onobrychis viciaefolia Scop.)组织培养物在5%DMSO+10%甘油+8%蔗糖的冰冻保护剂及以1℃/分钟的速度降温到-35—-40℃,停留2小时后,投入液氮,40℃水浴快速化冻等条件下,存活率达60—70%,并保持了高的分化能力。电子显微镜的观察结果表明,快速冰冻和1℃/分钟慢速冰冻至-35℃—40℃不停留,对细胞结构造成严重的致死性破坏;-35℃停留30分钟对细胞结构的损伤是可逆性的;停留2小时的其超微结构基本上与对照材料无明显差别。     

转BADH基因马铃薯无性繁殖二代耐盐性检测

在0%、0.3%、0.6%NaCl胁迫下,检测转BADH基因马铃薯及其受体亲本‘甘农薯2号’的盆栽植株耐盐性的结果表明:BADH基因的遗传性稳定且转基因植株的耐盐性比非转基因的强。     

Qualitative and Quantitative Analysis of Endogenous Jasmonoids in Potato Plant (Solanum tuberosum L.)

Qualitative and quantitative analyses of endogenous jasmonoids were done by liquid chromatography/selected ion monitoring (LC-SIM) using deuterium-labeled compounds as internal standards. To prove the practicality of this way of analyzing the contents of endogenous jasmonoids in plants, the method was used for estimating jasmonoids in potato plants.     

不同生理年龄马铃薯种薯芽中的内源激素含量变化及其对马铃薯植株生长发育的影响

测定云南马铃薯主栽品种‘合作88’不同生理年龄种薯芽中内源激素含量的结果表明,随着马铃薯种薯生理年龄的增加,各种内源激素含量均呈下降趋势,生理年龄30d以后的种薯中,IAA、GA_3,玉米素(ZR)和双氢玉米素(DHZR)下降显著,ABA下降相对缓慢;生理年龄30d的种薯,主茎长出的叶片数多,单株薯重高。     

Microtuberization in potato (Solanum tuberosum L.)

Twenty-two genotypes of potato (Solanum tuberosum L.) were induced to form microtubers under six in vitro culture conditions. Cultures maintained under a short photoperiod (10 h of 6–12 μmol m^–2 s^–1) and low temperatures (day 20°±2°C and night 18°±2°C) had both a higher yield (255 mg/plantlet) and a greater number (2/plantlet) of microtubers than those maintained under long days (16 h of 38–50 μmol m^–2 s^–1) combined with high temperatures (day 28°±2°C and night 25°±2°C) (yield 207 mg/plantlet; microtuber number, 0.9/plantlet), over a wide range of genotypes. After the plantlets had been cultured under long days for an initial period of 60 days, continuous darkness advanced microtuberization by 2–3 months in various genotypes. Under short-day and low-temperature conditions the addition of 6-benzylaminopurine increased microtuber yield from 255 mg/plantlet to 645 mg/plantlet and average microtuber weight from 115 mg to 364 mg. A similar pattern was observed under conditions of long days and high temperature, and continuous darkness and low-temperature. Microtubers produced under light had a greater number of eyes (maximum average: 5.96/microtuber) than those produced in the dark (maximum average: 3.50/plantlet). The genotype × cultural conditions interactions were significant indicating the importance of developing genotype-specific protocols to maximize microtuberization. Received: 17 September 1997 / Revision received: 12 December 1997 / Accepted: 1 January 1998     

反义酸性转化酶基因低温贮藏马铃薯块茎还原糖和淀粉含量的影响

对2个含有酸性转化酶(AcInv)反义基因的转基因马铃薯品系及对照品种进行低温贮藏(4℃)及室温还暖处理.随低温贮藏时间的延长,供试材料均表现出还原糖含量升高,总淀粉含量下降的趋势.低温处理40 d时,"Ac转Atlantic"和"Ac转甘农薯2号"的还原糖含量比未转基因品种低23%和18%.总淀粉含量分别比未处理前下降约1.0%和1.3%,支链淀粉含量分别下降约1.4%和1.7%,淀粉直/支比明显低于对照,分别为0.29和0.38.块茎的石蜡切片显示,转基因块茎中深蓝色淀粉颗粒明显少于未转基因对照.另外,对低温贮藏的块茎室温还暖后,2个转基因品系的还原糖含量仍低于对照品种.实验结果证明反义AcInv基因对低温贮藏下块茎还原糖和淀粉含量具有下向调节作用.     

Carbon isotope discrimination in irrigated and droughted potato (Solanum tuberosum L.)

Carbon isotope discrimination (Δ) was measured in irrigated and droughted potato. Under irrigation, Δ in leaflets at given nodes increased (P < 0.001) between 21 and 63 d after emergence (DAE), which was attributed to increasing stomatal conductance (g_s) during leaf expansion. The effect of leaf position on Δ was non-significant in mature leaves. Under drought, Δ decreased (P < 0.001) in successive leaves up the stem, reflecting changes in g_s and water stress. At each node Δ remained constant or decreased, suggesting that effects of water stress were greater than changes with leaf expansion. There were significant differences in Δ between cultivars in both treatments, and in the progressive decrease in Δ up the stem under drought. Differences in Δ between cultivars were consistent with differences in stomatal control of leaf water status following water stress. Values for Δ in tubers were consistently lower than in stem and leaf, and decreased more rapidly. Differences in Δ between cultivars did not reflect dry matter production in either treatment, and differences in water use were non-significant between cultivars under drought. So, plants can achieve similar dry matter production through different growth strategies when irrigated or droughted, and Δ does not provide a simple, indirect method of selecting for dry matter production under water stress.     

低温条件下转AcInv反义基因马铃薯品系的干物质、淀粉和还原糖含量变化

检测低温（4℃）贮藏条件下转AcInv反义基因与否的马铃薯品系块茎中干物质、淀粉和还原糖含量变化的结果表明：随着低温贮藏时间的延长,各转基因品系块茎中干物质含量变化不大,淀粉含量虽有下降但较为平缓;转基因品系中的还原糖含量增加幅度比受体品种的明显降低,转Aclnv反义基因的‘甘衣薯1号’和‘大西洋’块茎抗低温糖化能力明显高于未转AcInv反义基因的品系。     

Inter-plot competition in yield trials of potatoes (Solanum tuberosum L.) with single-drill plots

An experiment was carried out to assess the significance of inter-plot competition in a yield trial of potato cultivars. Seventeen cultivars were deliberately chosen and assessed for yield in single-drill and four-drill plots. Inter-plot competition for fresh-weight yield was a significant factor in the single-drill plots. It was modelled using a common competition coefficient with a covariate based on neighbour fresh-weight yields. In contrast, there was no statistically significant inter-plot competition for specific gravity. After adjustment for inter-plot competition, varietal ranking in estimated monoculture yield differed little from that based on unadjusted means. However, there was a reduction in the range of yield estimates, and a closer agreement with the observed pure-stand yields from the inner two drills of the four-drill plots. The adjustment for monoculture performance was most pronounced for the higher and lower yielding varieties, as expected from the assumption that the performance of high yielding varieties was enhanced in a competitive environment at the expense of low yielding ones. A general and flexible method of estimating competition coefficients in variety trials, together with a suitable algorithm, was developed and is explained in an appendix. It was used to check for inter-plot competition in a number of potato trials with single-drill plots and a large number of entries. Competition was found in some trials but not in others. Thus, where potato tubers are grown in single-drill plots for assessment of fresh-weight yield, adjustment should be made for inter-plot competition when evidence of inter-drill competition is found.     

Biochemical and bioassay analysis of resistance of potato (Solanum tuberosum L.) cultivars to attack by the slug Deroceras reticulatum (Muller)

A method is described for using young field slugs Deroceras reticulatum (Muller) in a bioassay study of biochemical resistance of potato (Solanum tuberosum L.) cultivars to slugs. Tuber parts or an artificial diet were provided as food sources. Comparisons were made of feeding, survival and weight gain between the susceptible cultivar Maris Piper and the resistant cultivar Pentland Dell. Biochemical analyses were made of these two cultivars and the resistant cultivars Stormont Enterprise and Majestic. Comparisons of tuber sections and peelings as food sources indicated factors affecting growth were located in the surface layers of the tubers. Phenolics and glycoalkaloids were concentrated in the surface layers but the amounts were similar in the susceptible and resistant cultivars and the bioassays indicated that neither acting alone could explain resistance. The amounts and distribution of free amino acids also did not correlate with resistance although when supplied in the artificial diet they partly inhibited feeding. Proteinaceous inhibitors of slug gut proteolytic enzymes were present throughout the tubers but were not concentrated in the surface layers and the amounts were similar in the different cultivars thus they too did not explain the difference in susceptibility between the cultivars. Bioassays using acetone extracts (low molecular weight substances) and acetone powders (high molecular weight substances) either alone or in combination indicated that the resistant cultivar Pentland Dell contained a high molecular weight substance which together with a low molecular weight substance from either the same cultivar or the susceptible Maris Piper could confer resistance. Bioassays using protein extracts supplied in the presence or absence of chlorogenic acid indicated that this mechanism could comprise enzymic oxidation of phenolics. Assays of phenolase confirmed this since activity was highest in the outer layers of the tubers and was highest in the three resistant cultivars. Thus the chief resistance factor identified was high phenolase activity acting rapidly on phenolics when the slug first bites the tuber surface. The quantity of phenolics per se did not control the resistance. Thus while phenolics must be available, resistance is compatible with low blackening on cutting the tuber.