热水处理对金柑果实采后腐烂及生理特性的影响

金柑是果皮和果肉同食的柑果类型,对采后处理要求极为严格。该研究以金柑(Fortunella crassifolia)为材料,研究了其经30、40和50℃热水浸泡后果实的腐烂率、失重率、可溶性固形物、硬度、有机酸、细胞渗透率以及抗氧化酶活性变化。结果表明:经30℃热水处理5 min的果实失重率高于对照,而经40℃和50℃处理的果实失重率低于对照或差异不显著。经热水处理的果实总酸含量略低于对照,可溶性固形物含量在18%上下波动且差异不显著。热水处理可提高果实硬度,降低贮藏前期果实细胞渗透率以及贮藏过程中果实过氧化物酶和超氧化物歧化酶活性,激发过氧化氢含量升高,可有效降低贮藏过程中金柑果实腐烂率,但不同采收期的金柑所需的热水处理温度和时间不同。对于1月初采收的果实,处理时间为5 min或10 min可降低果实腐烂率;2月初采收的果实,40℃或50℃热水处理10 min可有效降低果实腐烂率;3月初采收的果实,当处理温度达到50℃,处理时间达到10 min,才可有效降低果实腐烂率,且对果实品质没有明显的不利影响。     

O2和CO2配比对低温贮藏李品质及生理变化的影响

为了探索适宜‘黑宝石’李贮藏的气体参数,研究了不同气体成分(6.0%O2+5.0%CO2、6.0%O2+1.0%CO2、10.0%O2+5.0%CO2和10.0%O2+1.0%CO2)处理对贮藏及货架期‘黑宝石’李采后品质(硬度、总糖、可滴定酸和腐烂指数)、抗氧化酶(SOD、POD和CAT)活性及MDA含量的影响。结果显示:(1)在贮藏0~45 d期间,冷藏对照果实的腐烂指数在8%以下,其货架果实的硬度仍可下降;贮藏至75 d时,冷藏对照果实的腐烂指数达38%,而且其果实失去了软化能力。(2)气调处理可减缓低温贮藏李果实硬度的下降,降低果实的腐烂指数,维持货架果实的后熟能力,但6.0%O2+1.0%CO2处理对果实腐烂指数的影响不显著。(3)气调处理可提高低温贮藏李果实的SOD、POD和CAT活性,抑制这3种酶在货架模拟过程中的升高,且可降低低温贮藏及货架期果实的MDA含量。(4)气调贮藏中以6.0%O2+5.0%CO2处理的效果最佳,果实的贮藏期可达75 d。研究说明,常规冷藏(0~1.5℃)可满足‘黑宝石’李果实采后短期贮藏(<45 d)的需要,而适宜的气调贮藏可使其贮藏期限延长30 d左右。     

臭氧与海藻酸钠涂膜对葡萄的保鲜效果及其贮藏生理特性的影响

以采后"红地球"葡萄果实为试材,分别设置对照(CK)、250μL/L臭氧处理(O3)、0.3%海藻酸钠涂膜处理(M)、250μL/L臭氧+0.3%海藻酸钠涂膜处理(O3+M),在(0±0.5)℃条件下贮藏,通过测定贮藏过程中葡萄可溶性固形物含量、可滴定酸含量、呼吸强度、硬度、过氧化物酶(POD)、超氧化物歧化酶(SOD)、几丁质酶(CHI)、β-1,3-葡聚糖酶(GLU)的活性以及膜脂过氧化物质丙二醛(MDA)和总酚含量等的变化,统计果实失重率与腐烂率情况,观察各处理对葡萄保藏效果的影响。结果表明:与对照相比,250μL/L臭氧处理、0.3%海藻酸钠涂膜及250μL/L臭氧+0.3%海藻酸钠涂膜复合处理均能显著降低葡萄果实的失重率和腐烂率,抑制葡萄果实的呼吸上升,延缓硬度下降,提高果实抗性相关酶(POD、SOD、GLU、CHI)的活性,减少膜脂的过氧化程度,延缓果实总酚含量下降,有效改善葡萄的贮藏品质,并以250μL/L臭氧+0.3%海藻酸钠涂膜复合处理对葡萄果实保鲜效果最佳。     

纽荷尔脐橙留树和低温贮藏效果比较

以纽荷尔脐橙(citrus sinensis'Newhall')果实为试材,对50%留果量的留树贮藏和果实6℃低温贮藏过程中不同时期的果肉硬度、果皮总色差、O2产生速率、脯氨酸(Pro)含量、相对电导率、丙二醛(MDA)含量及脂氧合酶(LOX)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性进行测定.结果表明:两种贮藏方式下果肉硬度均下降,果皮总色差上升;LOX活性增加,SOD、CAT活性下降;O2、MDA、Pro积累,细胞膜受到伤害,导致胞内物质外流,细胞电导率增加.贮藏47d时,两种贮藏方式各指标基本上没有显著差异;贮藏47d至75d,留树贮藏的果实无论外观(果肉硬度、色泽)还是细胞膜的完整性都显著优于低温贮藏.     

壳聚糖涂膜对番荔枝冷藏期间某些生理生化指标的影响

经1％壳聚糖涂膜处理的番荔枝果实在冷藏（15℃）期间可溶性固形物（TSS）含量变化过程延缓,果实腐烂率显著降低,超氧化物歧化酶（SOD）和过氧化物酶（POD）活性提高,多酚氧化酶（PPO）活性和丙二醛（MDA）含量下降,过氧化氢酶（CAT）活性变化不明显。     

丁香精油对冷藏冬枣果实腐烂及诱导抗病相关酶活性的影响

对不同浓度丁香精油处理冬枣果实在0℃贮藏期间(60d)及藏后25℃货架期(5d)的果实腐烂率、诱导抗病相关酶活性和总酚含量的变化特征进行分析,以探索丁香精油抑制冬枣果实腐烂与抗病性诱导的关系。结果表明:丁香精油处理能有效抑制冬枣贮藏期果实腐烂的发生,提高其苯丙氨酸解氨酶、多酚氧化酶和过氧化物酶活性,诱导总酚含量的增加。经丁香精油处理冬枣果实在贮藏60d后25℃货架期5d时的腐烂指数得到明显下降,同时保持了较高的苯丙氨酸解氨酶、多酚氧化酶、过氧化物酶活性和总酚含量,并以0.50%丁香精油处理的效果最显著,其贮藏后货架期的果实腐烂指数较对照下降了45.5%。可见,丁香精油抑制贮藏冬枣果实的腐烂与抗病相关酶活性的升高密切相关,抗病性诱导是丁香精油处理抑制冬枣采后果实腐烂的重要原因之一。     

采后枸杞鲜果褐变与其活性氧代谢的关系

以采后'宁杞3号'枸杞鲜果为试材,研究其在(4±1)℃和(10±1)℃贮藏过程中果实褐变与活性氧代谢的关系.结果表明:枸杞果实褐变指数在两种贮藏温度下的贮藏初期(0～10 d)增加幅度均较小(分别为17.6%和5.1%),(10±1)℃下的果实从第15天显著增大(64.1%),而(4±1)℃下从第20天显著增大(67.9%).(4±1)℃贮藏果实的超氧歧化酶(SOD)活性和还原型抗坏血酸(AsA)含量在采后贮藏的前10 d增大,之后降低,贮藏后期又增大;超氧阴离子(O2-)产量在采后0～5 d降低,而后逐渐增大;过氧化氢(H2O2)和丙二醛(MDA)含量在采后0～5 d增大.之后前者降低又缓慢升高.与(10±1)℃贮藏果实相比,(4±1)℃下贮藏果实O2-产量显著降低,H2O2含量在贮藏第5天和第25天也显著降低,MDA含量在贮藏5～20 d显著降低;SOD活性在贮藏5～10 d显著提高.过氧化氢酶(cAT)活性和AsA含量明显提高;多酚氧化酶(PPO)活性在贮藏15～25 d显著下降,总酚含量在贮藏5～20 d显著增加.研究发现,枸杞果实褐变可能是细胞活性氧代谢失调,使PPO与酚类物质接触,导致酚类物质氧化的结果;(4±1)℃低温贮藏能通过调整鲜果活性氧代谢来有效延缓褐变进程.     

1-MCP对‘珍珠’番石榴采后生理和品质的影响

为探讨改善番石榴贮藏性能的方法,番石榴(Psidium guajava L. ‘Pearl’)果实用1-甲基环丙烯(1-MCP)结合冷藏(15℃)处理,研究其贮藏生理和品质的变化。结果表明：1 μL L-1 1-MCP处理能有效抑制番石榴果实软化和果皮退绿;1-MCP处理抑制了可溶性固形物(TSS)含量上升和维生素C含量的下降;同时,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性升高,多酚氧化酶(PPO)活性下降,延缓了果实中丙二醛(MDA)的积累。因此,1-MCP处理结合低温可有效改善珍珠番石榴的贮藏性能。 关键词：番石榴;1-MCP;贮藏生理;品质     

高O2或高CO2浓度气调贮藏对"那翁"甜樱桃采后生理和贮藏性的影响

研究了甜樱桃品种"那翁" ( Prunus avium L. cv. Napoleon)在1 ℃的高O2 浓度气调(CA-I: 70% O2+0% CO2)、高CO2 浓度气调 (CA-II: 5% O2+10% CO2)、自发气调 (modified atmosphere package, MAP) 和普通冷藏条件下果实生理、品质、耐藏性的变化.结果表明:与其他处理相比,高O2 浓度的气调可以抑制果实腐烂、减少果肉中乙醇含量,但果实的丙二醛(MDA)含量迅速上升、褐变严重.高CO2浓度的气调能有效抑制MDA含量上升的速率和多酚氧化酶(PPO)活性,保持果实硬度和维生素C含量,减少果实腐烂和褐变,延长贮藏寿命.不同处理对果实可溶性固形物含量的影响不大."那翁" 甜樱桃在5% O2+10% CO2气调中贮藏80 d能保持果实固有的风味品质.在MAP下, 70% O2+0% CO2和普通冷藏中的适宜贮藏期分别为40 d、20 d和30 d.     

1-甲基环丙烯对台湾青枣采后生理效应的影响

研究了台湾青枣(Ziziphus mauritiana Lam．cv．Liuxiang)在25℃下贮藏期间1-甲基环丙稀(1-MCP)处理对果实品质和一些生理指标的影响。结果表明：250μgL^-1的1-MCP有效抑制了果实腐烂和褐变。在25℃下贮藏12d,对照和处理的好果率分别为12．5％和92．5％。果实经1-MCP处理后,乙烯合成受到显著抑制,乙烯高峰出现延迟,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性提高,从而减缓了丙二醛(MDA)的积累和细胞膜透性的升高。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.