不同果色枸杞果实糖积累特征及其与蔗糖代谢酶活性的关系

以‘宁杞1号’（红色）、‘宁夏黄果’（黄色）和‘黑果’（黑色）3份不同果色枸杞为试材,测定枸杞果实发育过程中糖含量与蔗糖代谢酶活性的变化,并分析糖含量与蔗糖代谢酶活性的相关性,以探讨不同果色枸杞糖积累差异的生理基础,为进一步阐明枸杞品质形成及调控机理提供理论依据。结果显示：（1）气相色谱（GC）法检测结果为 ‘宁杞1号’果实含8种糖,‘宁夏黄果’含7种糖,‘黑果’仅检测到4种糖;且成熟期枸杞果实均以果糖、葡萄糖和蔗糖为主。（2）在枸杞果实发育过程中,各材料果实的果糖和葡萄糖含量呈现逐渐升高趋势,果实发育的后期升高幅度高于初期;而各材料蔗糖和赤藓糖含量却呈现出不同的变化趋势,不同发育时期材料间差异各异。（3）不同果色枸杞蔗糖代谢酶活性在枸杞果实发育过程中差异较大,其中酸性转化酶（AI）在果实发育的初期活性较低,材料间差别小,但在果实发育的后期活性高,材料间差异较大;从枸杞果实发育色变期到成熟期,供试材料AI和蔗糖合成酶（SS）活性高于中性转化酶（NI）和磷酸蔗糖合成酶（SPS）;在整个果实发育过程中‘黑果’保持着较低果糖含量和蔗糖代谢酶活性。（4）3种果色枸杞果糖含量均与AI活性达到显著相关关系,红色与黑色枸杞己糖（果糖和葡萄糖）含量与NI达到显著相关关系。研究表明,不同果色枸杞果实中的糖种类与含量、蔗糖代谢酶活性差异较大,AI活性升高有利于枸杞果糖的积累,转化酶在枸杞果实己糖积累过程中发挥着重要的作用。     

FaesAP2B基因在甜荞长雌蕊长雄蕊突变体lpls的表达分析

为弄清甜荞（Fagopyrum esculentum Moench.）长雌蕊长雄蕊突变体lpls花和籽粒发育调控的分子机制,从甜荞中克隆出1个长1 788 bp的AP2同源基因的cDNA序列,命名为FaesAP2B（GenBank登录号为MK290847.1）。序列结构分析表明：FaesAP2B基因包含1个长1 380 bp的完整开放阅读框（Open Reading Frame,ORF）,编码1个由459个氨基酸残基组成的AP2/ERF家族转录因子,该转录因子含有2个高度保守的AP2结构域,第1个AP2结构域前还存在1个由10个氨基酸残基组成的核定位信号区。用qPCR检测FaesAP2B基因在甜荞lpls突变体根、茎、幼叶、花被片、雄蕊、雌蕊以及发育4 d的果实共7种器官中表达的组织特异性显示：FaesAP2B在甜荞突变体lpls营养组织和生殖结构中均有表达,但其在花器官和果实等生殖结构中的表达量明显高于营养组织,且在雄蕊中的表达量最高,极显著高于其在其他6种组织中的表达量（LSD,P<0.01）,同时,FaesAP2B在花被片、雌蕊和发育4 d的果实中的表达量均极显著高于其在根、茎和叶等营养器官中的表达量（LSD,P<0.01）,但该基因在其根、茎、叶间的表达量无显著性差异。推测该基因可能主要参与调控甜荞lpls突变体花和果实的发育。     

外源5-氨基乙酰丙酸对设施番茄果实发育及糖酸品质的影响北大核心CSCD

番茄果实糖酸类物质的含量及比例直接影响其风味品质,前期研究表明,适宜浓度的外源5-氨基乙酰丙酸(ALA)能够促进果实的成熟并提高其芳香品质。该试验为探究外源ALA对番茄果实发育及其糖酸品质的影响,以番茄‘原味1号’(Solanum lycopersicum cv.Yuanwei No.1)品种为试材,于第4穗果授粉后10 d果实表面喷施0、100和200 mg·L^(-1)的ALA溶液,分析ALA对番茄果实形态、果皮色泽及果实不同部位组织中糖、酸类物质组分及含量的影响。结果表明:(1)外源ALA溶液能显著促进番茄果实横径、纵径的增加,提高果实单果重,还显著降低果实硬度,促进果实软化,提升果实口感,并提高了果实V_(C)和可溶性固形物含量。(2)果实不同部位组织(包括果肉、小柱和隔膜)糖类物质组分含量测定结果显示,外源ALA处理能够显著提高果实可溶性总糖含量(包括果糖、葡萄糖和蔗糖),并有利于糖类物质向果肉中积累。(3)在有机酸类物质中,除酒石酸含量增加外,外源ALA处理均能不同程度地降低果实各部位组织中酸类物质含量,从而显著提高番茄果实果肉部位糖酸比,提升果实糖酸品质。研究发现,在番茄果实发育过程中外源施用200 mg·L^(-1) ALA不仅能够促进果实发育及着色,提高单果重,提升果实的外观品质,还有利于果实糖酸品质的形成。     

五味子果色遗传假设

以资源调查过程中观察到的现象和收集到的资源为依据,对五味子果实颜色遗传规律进行探讨;认为五味子果色深浅为多基因控制的数量性状;果色分布受另一对基因控制;果色与果梗颜色受不同基因控制,其组合具有不完全自由性.     

葡萄Golden2-like转录因子家族的鉴定及其表达分析

本研究对葡萄（Vitis vinifera L.）的Golden2-like （GLK）转录因子家族进行了全基因组鉴定和表达模式分析,并利用品种‘玫瑰香’（V.vinifera cv.Muscat Hamburg）进一步验证其在低温胁迫下的响应。结果显示,葡萄Golden2-like家族共46个成员,分为5个亚族,同一亚族的保守结构域相似。46个VvGLK分别定位于细胞核、叶绿体、细胞质和过氧化物酶体中,其启动子区域含多种逆境应答顺式作用元件。基因芯片分析结果表明,22个Golden2-like基因在果实发育过程中变化显著。同时,有15、15和9个基因分别响应盐、干旱和低温胁迫。qRT-PCR分析发现26个基因参与低温应答。VvGLK41在所有胁迫处理中均下调表达。     

番茄果实早期发育的分子生理机制研究进展

番茄(Solanum lycopersicum)是目前世界上种植面积最广且最受欢迎的蔬菜作物之一, 也是肉果及茄科的重要模式植物。番茄果实发育主要分为早期果实发育和果实成熟2个时期, 但果实形态结构和大小主要决定于早期果实发育时期。该文围绕番茄早期果实发育时期植物激素、细胞周期、表观遗传和源库代谢等多方面调控的分子机制进行了综述, 旨在认识植物生长与发育的基本生物学问题及促进基础理论研究成果在生产中应用。     

温室滴灌条件下土壤水分亏缺对番茄产量及其形成过程的影响

采用小区试验,在温室滴灌条件下研究了不同生育阶段土壤水分状况对番茄果实大小、坐果数、畸形果及产量形成过程的影响,分析了温室滴灌条件下番茄总产量与灌水量的关系.结果表明：番茄苗期适度水分亏缺（田间持水量的50%～55%）可提高坐果率,畸形果形成减少,但果实总体偏小,果实成熟主要集中在采摘后期;开花坐果期过度水分亏缺（田间持水量的65%以下）虽可促进果实成熟,但降低了坐果数,易形成小果和畸形果;采摘期水分过高（田间持水量的80%以上）或过低（田间持水量的65%以下）均可降低番茄产量,水分亏缺（田间持水量的65%以下）则使坐果数降低、畸形果增加.各水分处理对果实成熟时间无明显影响;温室番茄总产量、灌溉水利用效率与全生育期灌水总量之间均呈二次抛物线关系;当番茄土壤水分（占田间持水量的百分比）下限控制在苗期60%～65%、开花坐果期70%～75%、成熟采摘期70%～75%时,番茄畸形果形成量减少,产量及坐果率较高,可作为滴灌条件下温室番茄适宜的土壤水分控制指标.     

番茄属(Lycopersicon)四个种的过氧化物酶同工酶分析

本文报告了应用连续浓度梯度聚丙烯酰胺凝胶电泳对番茄属Lyco-persicon的四个种:秘鲁番茄L.peruviaunm Mill.,多毛番茄L.hirsutum Humb.et Bonp,醋栗番茄L.pimpinellifolium(Jusl)Mill和普通番茄L.esculentum Mill.的86份材料,15个不同生育时期,不同器官以及同一器官的不同部位的过氧化物酶同工酶的分析结果。结果表明:L.Peruvianum的各个生育期和不同器官的过氧化物酶同工酶谱带叠加共有28条带,L.hirsutum有29条带,L.pimpinellifolium有28条带,L.esculentum有27条带。种间过氧化物酶同工酶谱型差异明显,种内不同生育期叠加总酶谱基本一致。在根、茎和叶中,这四个种的过氧化物酶同工酶酶谱和活性具有相似的生育期变化规律和器官分布规律.在果实发育过程中,种间过氧化物酶同工酶酶谱、活性及变化律规都不相同。本文还就同工酶谱型相似值的意义,野生资源及同工酶分析技术在番茄育种中的应用等问题进行了讨论。     

皱皮木瓜果实发育后期品质变化及其成熟阶段的划分初探

以湖北长阳产皱皮木瓜为材料,测定果实发育后期果实鲜质量、果长、果径、果色、果实硬度以及果肉干物质量、可溶性糖含量、总酸含量和总黄酮含量等品质指标的动态变化,划分不同成熟阶段,为判断果实适宜采收期、实现优质生产提供理论参考。结果表明:(1)皱皮木瓜果实发育后期果实鲜质量、果长、果径、果肉干物质量和可溶性糖含量均呈现上升趋势;果色由绿色、黄绿色渐变为淡黄色到黄色;果实硬度、果肉总酸和总黄酮含量呈先上升后下降趋势。(2)各品质指标快速变化的时间区域存在差异,果实鲜质量在花后105~150d增加较快,果色在150d后逐渐变黄,果实硬度在花后135~165d快速下降,果肉总酸、总黄酮含量则在花后105~120d快速增加至峰值。(3)根据主成分分析结果和各品质指标的变化特点,可初步将皱皮木瓜果实发育后期划分为未成熟(花后105d之前)、早期成熟(花后120~150d)和成熟(花后165~180d)3个阶段。研究表明,随着果实成熟度的提高,皱皮木瓜果实鲜质量、果色、果肉干物质量、可溶性糖含量等指标不断升高,果实硬度逐渐下降,其食用加工品质不断提升,而在早期成熟阶段(花后120~150d)果实的药用品质则相对较高。     

不同果色辣椒CCS基因克隆及表达分析

果实颜色是辣椒重要的商品性状之一。本研究以观赏椒GS6、Z1,甜椒SP01及黄色突变体SP02为材料,探究辣椒红素/辣椒玉红素合酶(CCS)基因在不同成熟果色辣椒中的序列差异和表达特性,初步解析辣椒不同成熟果色形成分子机理。研究结果显示：成熟色为红色的GS6、Z1和SP01中均能克隆到CCS全长基因,且序列无差异,其全长1497bp,编码498个氨基酸,只包含一个开放阅读框序列,没有内含子序列;而黄色突变体SP02中未能克隆出CCS基因;聚类和系统进化分析发现辣椒CCS基因与茄科作物的番茄、中华辣椒和灯笼辣椒等植物的亲缘关系较近;qRT-PCR分析结果显示：在GS6中,CCS基因在花中的表达量最高;在Z1和SP01中,CCS基因在果实中的表达量显著高于其他组织,在根中表达量最低;而在SP01的茎和叶以及SP02的所有组织中,CCS基因均未表达。在果实不同发育时期,CCS基因在SP01花后30 d（Ⅲ期）、GS6和Z1花后40d（Ⅳ期）表达量显著上升。研究结果表明,甜椒黄色突变体SP02果实颜色的形成可能和CCS基因的缺失或变异密切相关,而在成熟色为红色的辣椒中CCS基因的表达可能在果实颜色形成过程中发挥着重要的作用。     

Effects of chilling on tomato fruit texture

The effects of chilling on tomato ( Lycopersicon esculentum Mill cv. Caruso) texture were investigated using fruit stored at 22°C (nonchilled) or 5°C (chilled) for 28 days. or at 5°C for 15 days before transfer to 22°C to facilitate ripening during and additional 13 days (prechilled). Prechilled fruit exhibited symptoms of slight chilling injury, i.e. development of mealiness, accelerated softening relative to that of nonchilled fruit and nonuniform surface colour development. The firmness of all fruit decreased during ripening and chilled storage when measured by flat plate compression and puncture, especially during the early stages of ripening of nonchilled and prechilled fruit. The compression firmness of pericarp tissue similarly decreased during ripening of nonchilled and prechilled fruit, but was maintained during chilling. Total moisture content (ca 94%) of tissue, uronide content (32-35% w/w) and extracted β-galactosidase activity did not differ significantly ( P > 0.05) among fruit during ripening and chilled storage. The degree of uronide methyl esterification in ethanol-insoluble solids prepared from pericarp tissue (EIS) was relatively low for all fruit. i.e. <40%. EIS from which greater levels of pectinesterase were extracted (i.e. nonchilled>chilled>prechilled) exhibited decreased levels of uronide methyl esterification. Markedly elevated levels of β-glucosidase activity were extracted from prechilled EIS. Total polygalacturonase activity (mainly as PGI) and autolysis of enzyme-extracted EIS were inversely correlated ( P ≤ 0.05) only with the loss of nonchilled fruit and tissue firmness and prechilled fruit firmness. Results suggest a possible role for β-glucosidase in textural changes of prechilled fruit and tissue (e.g. loss of firmness, development of mealiness) and also implicate loss of skin strength in the softening of whole fruit during chilling.     

Sugar uptake by protoplasts isolated from tomato fruit tissues during various stages of fruit growth

The uptake of radioactive glucose and sucrose by protoplasts isolated from pericarp and placenta tissues of tomato ( Lycopersicon esculentum cv. Counter) fruit was investigated in relation to the dry matter accumulation rates of these tissues. Uptake of glucose by protoplasts isolated from pericarp tissue was highest in fruit of around 20 g fresh weight or 25 days after anthesis. Sucrose uptake by pericarp protoplasts was lower than that of glucose and did not show a peak of uptake. The maximum rate of glucose uptake by protoplasts from the pericarp was at the time when the tomato fruit was accumulating dry matter at the highest rate. Glucose uptake by placenta protoplasts was lower and at a similar level as sucrose.
Protoplast uptake of glucose, but not of sucrose, was partially inhibited by (1) p -chloromercuribenzene sulphonic acid, a sulphydryl group modifier; (2) erythrosin B, an H⁺-ATPase inhibitor; and (3) valinomycin, a K⁺-ionophore, suggesting that membrane transport of glucose by tomato fruit sink cells may be a carrier-mediated, energy-dependent process.
The main route of carbohydrate accumulation by tomato fruit during the period of rapid fruit growth may be by cleavage of sucrose by apoplastic acid invertase prior to hexose transport across the plasma membrane.     

Fine mapping of quantitative trait loci for improved fruit characteristics from Lycopersicon chmielewskii chromosome 1.

The near-isogenic line (NIL) TA1150 contains a 56-cM introgression from Lycopersicon chmielewskii chromosome 1 and has several interesting phenotypic characteristics including fruit with orange color, high levels of soluble solids, thick pericarp, small stem scars, and good firmness. A set of overlapping recombinant lines (subNILs) was developed and field tested to fine map the quantitative trait loci (QTL) controlling these traits. The results indicated that the solids, pericarp thickness, and firmness QTL are distinct from the color locus. Several of the QTL mapped in this study, including the soluble-solids QTL, probably correspond to QTL mapped in other wild species of tomato. However, analysis of a set of TA523 subNILs containing complementary introgressions from Lycopesicon hirsutum chromosome 1 suggests that this wild species may contain a different locus for improved soluble solids. Thus, it might be possible to combine the L. chmielewskii and L. hirsutum alleles for these loci in a single line with the potential for extremely highly soluble solids. The TA1150 subNIL TA1688 contains the smallest introgression of the solids locus (approximately 19 cM), as well as the pericarp thickness and firmness QTL, with a yield that was equivalent to two of the three control lines. Isolation of recombinant subNILs from TA1688 should break the linkage between orange color and high solids and provide a small introgressed segment for marker-assisted breeding and genetic improvement of processing tomato.     

Effect of tunicamycin on in vitro ripening of tomato pericarp tissue

Ripening of pericarp tissue from mature green, early breaker and late breaker stages of tomato ( Lycopersicon esculentum Mill. cv. Dombito) fruit development was inhibitied by tunicamycin. Ripening was evaluated by lycopene accumulation, chlorophyll degradation, rate of ethylene production and cell wall-bound polygalacturonase (EC 3.2.1.15) activity. Maximum inhibition of these ripening parameters occurred at a treatment of 240 μ M tunicamycin for 2 h except for cell wall-bound polygalacturonase activity, which was greatly inhibited by concentrations of 12 μ tunicamycin or higher. Tunicamycin treatment at 120 μ M for 2 h inhibited the incorporation of [³H]-mannose into macromolecules (about 70%) and pronase-sensitive material (about 65%) and the incorporation of [³H]-leucine into proteins (about 20%). Our results indicate that protein glycosylation plays an important role in the ripening of tomato pericarp tissue.     

A comparative study of melting and non-melting flesh peach cultivars reveals that during fruit ripening endo-polygalacturonase (endo-PG) is mainly involved in pericarp textural changes, not in firmness reduction

Peach softening is usually attributed to the dismantling of the cell wall in which endo-polygalacturonase (endo-PG)-catalysed depolymerization of pectins plays a central role. In this study, the hypothesis that the function of endo-PG is critical for achieving a melting flesh fruit texture but not for reducing fruit firmness was tested by comparing pericarp morphology and endo-PG expression and localization in melting (MF) and non-melting flesh (NMF) fruit at successive stages of ripening. MF Bolero, Springbelle, and Springcrest, and NMF Oro-A and Jonia cultivars were analysed. Both MF and NMF fruit were left to ripen on the tree and reached a firmness of <10 Newtons (N). The image analysis of pericarp tissues revealed that during softening the loss of cell turgidity was a process common to mesocarp cells of all MF and NMF fruit and was clearly visible in peaches with a firmness of less than ～20?N. In contrast, the loss of cell adhesion was a feature exclusively observed in ripe MF fruit pericarp. In this ripe fruit, large numbers of endo-PG isoforms were highly expressed and the enzyme localization corresponded to the middle lamella. As a consequence, wide apoplastic spaces characterized the pericarp of ripe MF peaches. In contrast, no loss of cell adhesion was observed in any NMF fruit or in unripe MF peaches. Accordingly, no endo-PG was detected in unripe NMF fruit, whereas few and poorly expressed enzyme isoforms were revealed in ripe NMF and in unripe MF peaches. In this fruit, the poorly expressed endo-PG localized mainly in vesicles within the cytoplasm and inner primary cell wall. On the whole the results suggested that endo-PG function was needed to achieve melting flesh texture, which was characterized by wide apoplastic spaces and partially deflated mesocarp cells. Conversely, endo-PG activity had no critical influence on the reduction of fruit firmness given the capacity of NMF peaches to soften, reaching values of 5-10?N. As in tomato, the change of symplast/apoplast water status seems to be the main process through which peach fruit regulates its firmness.     

Yield and post-harvest quality of tomato hybrids heterozygous at the loci alcobaça, old gold-crimson or high pigment

The effects of the fruit ripening mutant gene alcoba?a (alc) and color development mutants, old gold-crimson (ogc) and high pigment (hp), on yield and post-harvest quality of tomato fruits were investigated. Five tomato hybrids were obtained by crossing near isogenic lines with Flora-Dade background [Flora-Dade (alc+/alc+ ogc+/ogc+ hp+/hp+), TOM-559 (alc/alc ogc+/ogc+ hp+/hp+), TOM-591 (alc/alc ogc/ogc hp+/hp+), TOM-593 (alc/alc ogc+/ogc+ hp/hp), and TOM-589 (alc/alc ogc/ogc hp/hp)] with the pollen parent line Mospomorist (alc+/alc+ ogc+/ogc+ hp+/hp+). Hybrid fruit was harvested at the breaker stage and stored on shelves at 15oC and 60% relative humidity for 16 days, and then evaluated for firmness, development of red color, and carotenoid contents. The different genotypic combinations at the loci alc, ogc and hp had no effect on fruit yield. The alc+/alc hybrid genotype significantly increased fruit firmness and significantly delayed the development of red color in maturing fruit. Simultaneous usage of ogc+/ogc and hp+/hp promoted an increase in the red color and lycopene content of alc+/alc hybrids, but did not have any additional effect on fruit firmness.     

Effect of water on the ripening of pericarp disks from tomato fruits

Color change, a measure of the ripening of pericarp disks of tomato fruits (Lycopersicon esculentum Mill. cv. Moneymaker), was delayed by osmotic water uptake. An even greater delay occurred when substances from the disks were allowed to leach out or to diffuse into agar, indicating the existence of a water-soluble substance(s) necessary for the ripening process. Osmotic solutions, allowing for more leaching, were more inhibitory to color development than the same amount of distilled water. The ripening process of tomato fruit disks can thus be disturbed by such processes as washing, infiltration, or incubation with solutions.