桃果实细胞内糖酸分布对果实甜酸风味的影响

以成熟‘白凤’桃果实为实验材料,采用区室化分析方法计算细胞内液泡、细胞质和细胞间隙中各糖酸组分的含量,并用调查问卷的方式对成熟桃果实甜酸风味进行评价打分,研究果肉细胞内各糖酸组分含量及其分布对果实甜酸风味的影响。结果表明:(1)成熟桃果实中可溶性糖(蔗糖、葡萄糖、果糖和山梨醇)在液泡、细胞质和细胞间隙的含量分别为27.3、11.6和9.0mg·g-1,有机酸(苹果酸、柠檬酸、奎宁酸和莽草酸)含量分别为2.09、0.94和0.35mg·g-1;蔗糖和苹果酸含量分别占果实可溶性糖和有机酸含量的80.6%和77.0%,是成熟桃果实中糖和酸的主要储存形式。(2)果实细胞内各糖酸组分通过细胞膜的渗透速率明显高于液泡膜。(3)块状处理桃果实液泡、细胞质与细胞间隙中的糖含量比、酸含量比及糖酸比分别为3.0∶1.3∶1.0、6.0∶2.7∶1.0、13.9∶12.4∶23.1,而匀浆处理果实的细胞结构被破坏,其不同细胞器中的比例分别为1.0∶1.0∶1.0、1.0∶1.0∶1.0、14.0∶14.0∶14.0;块状果实风味评价得分(2.99)明显高于匀浆处理果实(1.98)。研究认为,桃果实细胞中液泡、细胞质和细胞间隙之间糖酸含量以及糖酸比的差异可能是导致果实甜度风味变化的重要原因。     

八个贵州地方桃品种果实甜酸风味品质分析

为了评价贵州地方桃品种果实的甜酸风味品质,以主栽桃品种‘燕红’作对照,采用高效液相色谱法测定了贵州8个地方桃品种的果肉糖酸组分及含量。结果表明:(1)8个地方桃品种果肉中糖主要由蔗糖、葡萄糖、果糖和山梨醇组成,其中蔗糖的平均含量最高(55.62 mg/g),约占总糖的71.30%,但变异系数仅为17.92%;8个地方桃品种中,‘米桃’的葡萄糖与果糖含量差异较大,其果糖/葡萄糖的比值为1.21,而其它7个品种的葡萄糖与果糖含量相近。(2)8个地方桃品种果肉中有机酸主要由苹果酸、柠檬酸、奎宁酸和莽草酸组成,其中苹果酸含量最高,约占总酸的60.61%,但在‘白花桃’果实中有机酸含量以奎宁酸为主。(3)对8个地方桃品种果实的糖酸组分进行主成分分析发现,苹果酸含量和山梨醇含量的载荷系数分别为0.910和0.897,说明它们是影响果实甜酸风味的主导因素,且对改善果实的甜酸风味品质具有重要作用。8个贵州地方桃果实的甜酸风味分别为:‘黄腊桃’为甜,‘血桃’、‘青桃’、‘镇远桃’、‘红枫桃’为酸甜,‘白花桃’、‘西桃’和‘米桃’为酸。     

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

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。     

番石榴果实蝇与桃实蝇的形态区别

介绍我国口岸截获频率较高的2种形态相似的实蝇---番石榴果实蝇Bactrocera (Bactrocera) correcta(Bezzi) 和桃实蝇Bactrocera zonata Saunders的鉴别特征。两者主要区别在于桃实蝇具1对卵圆形黑色颜斑,中胸背板红褐色。     

梨果实糖酸含量及比值对其综合品质的影响（简报）

对梨90个品种（品系）果实的糖和酸含量的测定结果表明,含酶量是影响梨综合品质的主要因子之一。当含酸量特别高时,几乎没有优质的果实;而很低时,优质果所占的比重则较大。一般20～60的糖酸比是优质果实所要求的。酸度适中时,糖酸比对品质影响的规律性不明显。怪味、石细胞多少等因素,可使某些品种偏离上述结论。     

套袋遮光对欧李果实糖酸和类黄酮含量的影响

【目的】考察不同光照时间及强度对欧李果实糖酸和类黄酮含量的影响,为后期深入探讨光照影响果实品质的分子机制提供参考依据。【方法】以欧李品种‘农大6号’和‘农大7号’为试验材料,采用3种不同遮光率（30%、55%和100%）的果袋分别在果实膨大期和转色期进行套袋处理,测定其果实单果质量、可滴定酸含量、可溶性固形物含量和类黄酮含量。【结果】（1）两品种单果质量和果实可溶性固形物含量均表现为果实膨大期处理低于果实转色期处理,且均随着果袋遮光率的升高而逐渐降低。（2）‘农大6号’可滴定酸含量在套袋处理下均明显降低,且果袋遮光率越高、套袋时间越长,降酸效果越明显,而‘农大7号’可滴定酸含量受影响较小。（3）套袋‘农大6号’类黄酮含量均高于对照,并随着果袋遮光率的增加先升后降,且膨大期处理高于转色期处理。套袋‘农大7号’类黄酮含量仅在果袋遮光率30%时显著高于对照,且膨大期处理显著低于转色期处理,其含量随着果袋遮光率增加在膨大期逐渐增加,在转色期先降后升。【结论】套袋能有效改善欧李果实糖酸和类黄酮含量,‘农大6号’以膨大期套袋为宜,‘农大7号’则以转色期套袋效果更好,而且均以55%遮光率果袋对两品种糖酸和类黄酮含量综合改善效果最佳。     

采前套袋微环境变化对桃果实品质的影响

为明确套袋微环境变化对桃果实品质的影响机制,筛选适合晚熟桃套袋的无纺布果袋,以晚熟桃品种‘夕空’为材料,以不套袋为对照,研究了采前白、黑、蓝、紫色无纺布袋内微环境(温度和湿度)的日变化特征及其对果实品质的影响。结果表明:温度与湿度日变化曲线呈相反的趋势。白天不同处理的温度变化呈先升高后降低的趋势,峰值出现在中午12:00之后;湿度变化则呈"V"型。套袋微环境中的平均温度和湿度均较对照升高。采前不同处理袋内微环境变化存在差异,对桃果实品质形成的影响各异。套袋果实的亮度值(L)均较对照显著提高,而果皮中花色素苷(Ant)含量显著降低,可溶性固形物含量(SSC)、带皮果实硬度和去皮果实硬度均与对照差异不显著。套黑色无纺布袋并在采前拆袋的果实红色饱和度(a)、色饱和度(C)、a/b比值(b为黄色饱和度)和果皮中Ant含量较对照显著降低,采前拆袋并未显著改善‘夕空’桃的外观品质。紫色无纺布套袋处理的果实a值和a/b比值、果皮中Ant含量、果肉中总糖含量及糖酸比都较低。白色与蓝色无纺布套袋处理的果实相比较,单果重、果皮中Ant含量、C值、果肉中总糖含量及糖酸比差异不显著,但具有较高的a值和a/b比值。研究结果表明,在长江中下游地区,白色无纺布果袋对晚熟桃套袋较为适合。     

膨大期果面喷施IAA对桃成熟期果实性状和相关基因表达的影响

为明确桃果实发育后期外源生长素对果实成熟的影响及更深入的认识生长素调控果实发育与成熟的机制,本研究以桃品种‘小白凤’为试材,采用不同浓度的外源IAA(200,10,0.1μmol/L)喷施第2次快速膨大期的桃果实,在处理后10,20,30 d分别取样,分析桃果实的硬度,糖组分(蔗糖、葡萄糖、果糖、山梨醇),果胶,纤维素含量以及乙烯释放量的变化,并对200μmol/LIAA处理后30 d及对照组的果实进行了转录组测序分析,深入认识生长素调控桃果实成熟的作用和机理。结果表明,(1)IAA处理后30 d时,200μmol/L处理组桃果实果肉硬度与对照组相比显著增加,成熟期平均延迟5 d,而10,0.1μmol/LIAA处理组与同期对照组间无显著差异。(2)果肉蔗糖含量在0.1,200μmol/LIAA处理后30 d显著低于同期对照组,在10μmol/LIAA处理后30 d时与对照组无显著差异;葡萄糖、果糖和山梨醇含量在各浓度IAA处理后30 d时多与对照组间无明显差异。(3)在处理30 d时,果肉中可溶性果胶含量在0.1μmol/L IAA处理组与对照组无显著差异,在10,200μmol/LIAA处理组均显著低于对照组,此时不同浓度IAA处理桃果肉中不可溶果胶和纤维素含量均与对照组之间无显著差异。(4)在IAA处理后10,20,30 d时,果实乙烯释放量均表现为0.1,10μmol/L处理与对照组无显著差异,200μmol/L处理组显著低于对照组。(5)转录组数据显示,200μmol/L IAA处理与对照组中共存在86个差异表达基因,KEGG分析发现其中有6个与果实发育成熟密切相关的代谢途径中多个基因的表达谱发生显著变化,且变化趋势与已测定的生理指标数据吻合。综合分析表明200μmol/L的外源IAA处理第2次快速膨大期的桃果实能够延缓果实成熟的进程。     

植物生长调节剂对‘火焰无核’葡萄果实着色及品质的影响

为了探究S-ABA、MeJA、COR 3种植物生长调节剂对‘火焰无核’葡萄果实着色及品质的影响,筛选出促进葡萄果实着色和品质提升的最佳处理,设置100 mg/L S-ABA、60 mg/L MeJA、2 000倍COR稀释液3个处理,于转色初期蘸穗,处理后至成熟期分7次采样,对果实粒重、纵横径以及可溶性固形物、总酸、花色苷、叶绿素、类胡萝卜素和酚类物质含量等进行连续测定分析。结果表明：(1)S-ABA、MeJA、COR处理均可以促进果实着色,显著提高果面色泽参数a^*、红色葡萄果实颜色指数(CIRG),并降低色泽参数L^*、b^*和色度角h;3个处理花色苷含量分别比对照显著提高169.09%、31.55%、142.27%。(2)S-ABA、MeJA、COR处理均可以提高果实品质,其可溶性固形物含量分别比对照显著提高9.17%、7.45%、9.74%,总酸含量分别降低6.81%、4.14%、9.25%,固酸比分别提高17.90%、12.16%、20.82%。(3)S-ABA、MeJA、COR处理的果实粒重、纵径、横径增大,类黄酮...     

热激处理对冷藏桃果实的生理效应(简报)

桃果实经适宜的热激处理后,其在贮藏期间的呼吸速度、细胞膜透性、丙二醛（MDA）的积累及多酚氧化酶（PPO）活性都减小。在一定程度上还可以保持果实的硬度,降低酸度,减少腐烂,增加耐藏性。以37℃处理2d的效果为佳。     

Arsenic Uptake and Accumulation in Rice (Oryza sativa L.) at Different Growth Stages following Soil Incorporation of Roxarsone and Arsanilic Acid

Experiments were conducted with rice (Oryza sativa L.) by adding 0, 10, 20, 30, 40, 50 mg kg^-1 of arsenic (As) to soil (with roxarsone and arsanilic acid, presented as As concentrations) at a field with an isolation chamber. The aims were to evaluate the effects of As- (roxarsone or arsanilic acid) contaminated soil on rice agronomic parameters and uptake of As in different plant parts of the rice plant. The results showed that As (roxarsone or arsanilic acid) could significantly reduce plant height, effective tiller number, straw weight and grain yield (P < 0.01). As concentrations in different parts of the plant varied with the growth stages, and behaved similarly. At the maturing stage, the level in different parts peaked in all treatments, with tissue As concentrations showing the pattern: root > leaf > stem > husk > grain. In addition, at the mature stage, the As concentrations in different parts of the rice plant increased with increasing concentrations of roxarsone and arsanilic acid. The highest concentration of As found in grain was 0.82 mg kg^-1, which did not exceed the statutory permissible limit for rice grain (1.0 mg As kg^-1), and in the leaf and stem it was approximately 6.0 mg kg^-1, which was significantly higher than that in the controls. The results showed that rice could accumulate As from contaminated soil (roxarsone or arsanilic acid), which may be transferred to human beings via the food chain.     

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.     

氮、磷、钾肥配施对'红叶'南天竹叶片色素和 可溶性糖含量的影响及相关性分析

以2年生'红叶'南天竹(Nandina domestica'Hongye')盆栽苗为实验材料,根据L16(45)正交实验设计进行3因素(包括氮、磷和钾肥)4水平(N单株施用量分别为0.0、18.4、36.8和55.2 mg,P2O5单株施用量分别为0.0、14.4、28.8和43.2 mg,K2 O单株施用量分别为0.0、0.8、1.6和2.4 mg)施肥实验,对2015年11月5日至2016年1月20日期间各组叶片的光合色素(包括叶绿素a、叶绿素b、总叶绿素和类胡萝卜素)、花色素苷和可溶性糖含量进行了比较;在此基础上,对叶片色素和可溶性糖含量及各肥料单株施用量进行了Pearson相关性分析.结果表明:总体来看,各组的光合色素和可溶性糖含量显著高于对照(N、P2O5和K2O单株施用量均为0.0 mg)组,而花色素苷含量则显著低于对照组.其中,T14(N、P2O5和K2O单株施用量分别为55.2、14.4和1.6 mg)、T15(N、P2O5和K2O单株施用量分别为55.2、28.8和0.8 mg)和T16(N、P2O5和K2O单株施用量分别为55.2、43.2和0.0 mg)组的光合色素含量均较高,T2(N、P2O5和K2O单株施用量分别为0.0、14.4和0.8 mg)、T3(N、P2O5和K2O单株施用量分别为0.0、28.8和1.6 mg)和T4(N、P2O5和K2O单株施用量分别为0.0、43.2和2.4 mg)组的花色素苷含量均较高,T3和T4组的可溶性糖含量均较低.极差分析结果表明:N单株施用量对光合色素含量的影响最大,K2 O单株施用量的影响最小;N单株施用量对花色素苷和可溶性糖含量的影响最大,P2 O5单株施用量的影响最小.相关性分析结果表明:N单株施用量与各光合色素含量呈极显著正相关,与可溶性糖含量呈显著正相关,与花色素苷含量呈极显著负相关;而P2O5和K2O单株施用量与上述指标的相关性均不显著.各光合色素含量间存在极显著正相关,并与可溶性糖含量呈显著正相关,与花色素苷含量呈极显著负相关.此外,花色素苷含量与可溶性糖含量呈显著负相关.研究结果显示:高氮能够延长'红叶'南天竹的绿叶期,低氮能够促进其叶片呈现红色,因此,在园林栽培过程中应根据实际需要施肥.     

Effects of inter- and extramuscular myofascial force transmission on adjacent synergistic muscles: assessment by experiments and finite-element modeling

The effects of inter- and extramuscular myofascial force transmission on muscle length force characteristics were studied in rat. Connective tissues at the bellies of the experimental synergistic muscles of the anterior crural compartment were left intact. Extensor digitorium longus (EDL) muscle was lengthened distally whereas tibialis anterior (TA) and extensor hallucis longus (EHL) were kept at constant muscle–tendon complex length. Substantial differences were found in EDL force measured at the proximal and distal tendons (maximally 46% of the proximal force). EDL with intact inter- as well as extramuscular connections had an increased length range between active slack and optimum length compared to EDL with extramuscular connections exclusively: optimum muscle length was shifted by more than 2 mm. Distal EDL lengthening caused the distal force exerted by TA+EHL complex to decrease (approximately 17% of the initial force). This indicates increased intermuscular myofascial force transmission from TA+EHL muscle complex to EDL muscle.

Finite-element modeling showed that: (1) Inter- and extramuscular myofascial force transmission leads to a substantial distribution of the lengths of the sarcomeres arranged in series within muscle fibers. Distribution of stress within the muscle fibers showed that the muscle fiber cannot be considered as a unit exerting equal forces at both ends. (2) Increased heterogeneity of mean fiber sarcomere lengths (i.e., a “parallel” distribution of length of sarcomeres among different muscle fibers) is found, particularly at high muscle lengths. This also explains the shift in muscle optimum length to higher lengths.

It is concluded that inter- and extramuscular myofascial force transmission has substantial effects on muscle length–force characteristics.     

Acetylcholinesterase in Cocultures of Rat Myotubes and Spinal Cord Neurons: Effects of Collagenase and cis-Hydroxyproline on Molecular Forms, Intra- and Extracellular Distribution, and Formation of Patches at Neuromuscular Contacts

Cultures of rat myotubes from 18-day-old embryos produce both globular (G) and asymmetric (A) forms of acetylcholinesterase (AChE; EC 3.1.1.7), mostly G1, G4, and A12 and a small proportion of A8. We show that all forms are partly intracellular and partly exposed to the extracellular medium; the A forms and their intra- and extracellular distribution are not modified when myotubes are grown in the presence of spinal cord neurons. In these cocultures, however, AChE patches may be detected immunohistochemically at sites of neuromuscular contacts. These patches represent a very minor proportion of AChE activity. We found that collagenase removes AChE patches but not the acetylcholine receptor clusters with which they coincide. This digestion specifically decreases the level of the A12 form. cis-Hydroxyproline, an inhibitor of collagen synthesis, reduces the level of G1 and blocks the synthesis of A forms.     

Effects of short chain fatty acid producing bacteria on epigenetic regulation of FFAR3 in type 2 diabetes and obesity

The human gut microbiota and microbial influences on lipid and glucose metabolism, satiety, and chronic low-grade inflammation are known to be involved in metabolic syndrome. Fermentation end products, especially short chain fatty acids, are believed to engage the epigenetic regulation of inflammatory reactions via FFARs (free fatty acid receptor) and other short chain fatty acid receptors.