Contents of Sugars, Fruit Acids, Amino Acids and Phenolic Compounds of Apple Fruits i n Relation to their Susceptibility to Botryosphaeria ribis

Five apple cultivars showing different levels of susceptibility to Botryosphaeria ribis were used to study the relationship between susceptibility and contents of sugars, fruit acids, amino acids and phenolic compounds in the fruits at various stages of maturity. Immature fruits of all the cultivars tested were completely resistant until 10 July. The fungus grew better on the yellow-coloured cultivars than the red-coloured cultivars. The low amount of reducing sugars and also the high levels of fruit acids, amino acids and total phenols were found in immature apple fruits, irrespective of cultivar. No consistent differences between the cultivars were recognized with regard to the contents of soluble sugars, fruit acids and phenols in fruit flesh during the maturity of fruits. However, only the levels of total soluble amino acids in fruit flesh and of total phenols in fruit peel at late stage of maturity consistently varied between the cultivars. The dark red-coloured, resistant cultivars Miller spur and Starkrimson showed higher contents of amino acids and phenols in fruit tissues than did the yellow-coloured, susceptible cultivars.     

采后钙处理对梨果实钙的形态和果胶及相关代谢酶类影响的研究

研究了黄花梨经浸钙处理后,果实钙形态转变及果胶含量、多聚半乳糖醛酸酶（PG）和果胶甲酯酶（PME）活力的变化,以及果实硬度的变化。结果表明：浸钙处理的果实总钙含量显著提高,其硬度明显高于对照,且有利于细胞膜透性的保持;梨果实中的NaCl溶性钙最多,其次是水溶性钙,醋酸溶性钙和HCl溶性钙含量较少。在果实贮藏21d时,水溶性钙含量有一个上升的过程,而NaCl溶性钙则有一个下降的过程。浸钙处理后,除醋酸溶性钙外,果实中的水、NaCl和HCl溶性钙含量均有显著的提高。浸钙处理明显抑制了果胶的降解进程与PG的活力,但对PME抑制作用不明显。浸钙处理能提高果实硬度可能与浸钙处理抑制了PG活力有关。     

Diversity of Unavailable Polysaccharides and Dietary Fiber in Domesticated Nopalito and Cactus Pear Fruit (Opuntia spp.)

The aim of this study was to quantify mucilages, pectins, hemicelluloses, and cellulose of nopalitos (edible, as vegetable, young cladodes of flat-stemmed spiny cacti) of most consumed Mexican cultivars, and sweet and acid cactus pear fruits of Opuntia spp. The hypothesis is that, regardless of their unavailable polysaccharides diversity, nopalitos and cactus pear fruits are rich sources of soluble and insoluble dietary fiber. Twelve cultivars of Opuntia spp. were used. Nopalitos had a significant variation in structural polysaccharides among the cultivars: mucilages (from 3.8 to 8.6% dry matter (DM)) averaged near a half of pectins content (from 6.1 to 14.2% DM) and tightly bound hemicelluloses (from 2.2 to 4.7% DM), which were the less abundant polysaccharides, amounted 50% of the loosely bound hemicelluloses (from 4.3 to 10.7% DM). Acid fruits (or 'xoconostle') had significantly higher unavailable polysaccharides content than sweet fruit, and contain similar proportions than nopalitos. Unavailable polysaccharides represent a high proportion of dry tissues of nopalitos and cactus pear fruits, composition of both of these soluble and insoluble polysaccharides (total dietary fiber) widely vary among cultivars without an evident pattern. Nopalitos and cactus pear fruit can be considered an excellent source of dietary fiber.     

谷氨酸和TDZ对荔枝果皮着色及果实品质的影响

为提前或延迟果实的成熟,改善果实品质,以荔枝(Litchi chinensis Sonn.)早熟品种‘三月红’和‘水东’为试验材料,在盛花后50 d用谷氨酸(Glu)和TDZ(Thidiazuron)进行处理,研究Glu和TDZ对果皮着色和果实品质的影响。结果表明,Glu能促进果皮转红,500~1500 mg L-1范围内随浓度增加果皮红色面积加大,果皮的花青苷含量增加。1500 mg L-1Glu处理的‘三月红’‘、水东’果皮花青苷含量分别达到8.62 U g-1、11.53 U g-1,分别比对照高出1.33、1.25倍。同时,Glu处理能促进‘三月红’总糖的积累,但对两品种果实大小和质量的影响不大。TDZ显著迟滞果实着色,果实转红延后,果皮花青苷含量降低。5.0 mg L-1TDZ处理的‘三月红’‘、水东’果皮花青苷仅为1.23和3.4 U g-1,显著低于对照。TDZ处理两品种果实的可溶性固形物、总糖含量均下降,但果实大小和质量均增加。因此,Glu能促进荔枝果实转色成熟,TDZ则抑制果实转色。     

Comparative analysis of peach and pear fruit volatiles attractive to the oriental fruit moth,Cydia molesta

Cydia molesta is an important pest of peach and pear fruits late in growing season. We identified and quantified volatiles from immature and mature fruits of peach and pear using gas chromatography-mass spectrometry. Antennally, active compounds were identified by gas chromatography-electroantennogram detection and were further tested in the field. Consistent electroantennographic activity was obtained for nine compounds from headspace collections of the mature fruits of two peach and two pear varieties. Esters were the major components, but qualitative and quantitative differences were found among four odor profiles. Blends mimicking pear fruit volatiles were more attractive to both sexes than blends mimicking peach fruit volatiles in both orchards. Our finding indicated that mixtures mimicking peach and pear fruit volatiles attracted both females and males of C. molesta, and these host volatiles may also be involved in the host switch behavior from peach to pear in mid-late season.     

脐橙果实贮藏过程中主要有机物质含量的变化

对朋那脐橙、纽荷尔脐橙和红肉脐橙果实采后室温贮藏过程中主要有机物质含量进行分析,结果表明,贮藏期间,果实可溶性固形物含量10d前略有上升,10d后的变化各品种间有差异;可滴定酸含量显著下降;固酸比显著上升;维生素C含量变化趋势因品种而异;可溶性蛋白质含量在贮藏过程中呈上升趋势。上述各指标在贮藏各时期不同品种间有明显差异。     

Fruit Softening III. Requirement for Oxygen and pH Effects

The regulation of the softening of the cortical tissue of appleand pear fruits was investigated. Transfer of pear fruits toa nitrogen atmosphere arrested fruit softening and pectin degradationwithin 24 h. Anoxia also inhibited softening of discs cut fromripening pear fruits within 6 h, but polygalacturonase (EC 3.2.1.15 [EC] )activity was not substantially impaired and pectin degradationcontinued as in air. Discs of apple tissue softened more slowlythan pear but apple discs were firmer after 24 h under anoxiathan in air. Softening of pear tissue could be reversed by infiltration withpH 8.0 buffer or calcium chloride solution up to day 3 of ripeningat 18 °C. Buffer at pH 3.0 had no effect on fruit firmnessbut eliminated the effect of calcium in a combined treatment.A mixture of buffer at pH 80 and calcium chloride increasedfirmness more than either treatment alone. A similar reversalof softening could be achieved with apple fruit tissue afterstorage for 28 weeks.     

套袋对梨果实发育过程中糖组分及其相关酶活性的影响

以翠冠和黄金梨为试材,测定套袋和未套袋(对照)梨果实发育时期果实中蔗糖、葡萄糖、果糖和山梨醇含量以及蔗糖代谢相关酶酸性转化酶(AI)、中性转化酶(NI)、蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性,并对果实中糖组分积累与酶活性的关系进行了分析.结果表明:(1)两梨品种套袋果实在发育过程中蔗糖、葡萄糖、果糖、山梨醇和糖代谢相关酶活性变化趋势与对照基本一致,套袋果实糖含量均低于对照但差异不显著,而各相关酶活性在两类果实间差异表现各异.(2)在梨果实发育早期,果实中以分解酶类为主,糖分积累低;发育后期以合成酶类为主,糖分积累多.(3)两品种套袋和对照果实AI活性与葡萄糖含量均呈显著或极显著正相关,SS合成方向活性与蔗糖含量均为极显著正相关,且翠冠对照果SPS活性与蔗糖含量呈极显著正相关.可见,套袋通过提高果实发育早期转化酶(Inv)活性,降低果实后期蔗糖磷酸合成酶(SPS)、蔗糖合成酶(SS)的活性来影响糖分积累,从而影响梨果品质.     

果实种类及发育阶段对梨小食心虫幼虫钻蛀率和蛹重的影响

【目的】明确梨小食心虫Grapholitha molesta在寄主果实上的钻蛀率和蛹重与寄主种类和果实发育阶段的关系,为其田间预测预报和综合防控提供技术依据。【方法】在室内条件下测定了接卵后72 h梨小食心虫初孵幼虫在不同发育阶段的3个种共6个品种水果［苹果Malus pumila (嘎啦苹果), 桃Amygdalus persica (大久保毛桃、丰白毛桃和霞光油桃), 梨Pyrus bretschneideri (砀山酥梨和玉露香梨)］果实上的钻蛀率以及在不同果实状态的4个水果品种(大久保毛桃、丰白毛桃、砀山酥梨和玉露香梨)果实上72 h的钻蛀率;比较了接卵后24 h和72 h初孵幼虫在不同发育阶段的3个苹果品种(嘎啦苹果、富士苹果和金冠苹果)果实上的钻蛀率;并测定了不同发育阶段的金冠苹果、富士苹果、嘎啦苹果、砀山酥梨和丰白毛桃上的梨小食心虫蛹重。【结果】接卵后72 h梨小食心虫初孵幼虫在6个不同水果品种果实上的钻蛀率从高到低依次为：霞光油桃＞嘎啦苹果＞砀山酥梨＞玉露香梨＞大久保毛桃＞丰白毛桃;除霞光油桃外,其他5个水果品种果实的发育阶段显著影响初孵幼虫钻蛀率。对于嘎啦苹果,接卵后72 h初孵幼虫在其幼果上的钻蛀率最高(73.69%),在其着色期果实上钻蛀率最低(32.51%);在大久保毛桃、丰白毛桃、砀山酥梨和玉露香梨上,接卵后72 h初孵幼虫的钻蛀率均随果实生长发育而增加。初孵幼虫在3 个苹果品种着色期和成熟期果实上的钻蛀率随处理时间的增加而显著下降,而在其幼果上变化不显著。寄主种类及其发育阶段也显著影响梨小食心虫蛹重,成熟毛桃和梨饲养的雌、雄蛹重显著高于未成熟果实饲养的蛹重,着色期苹果不利于蛹重的增加。【结论】果实种类及发育阶段显著影响梨小食心虫初孵幼虫钻蛀率和蛹重,取食成熟期梨和桃的梨小食心虫初孵幼虫钻蛀率和蛹重显著高于取食未成熟果实的个体。     

5个番石榴品种果实食用品质和香气特征分析

为比较番石榴(Psidium guajava)不同品种果实的外观、营养价值和香气特征,采用国家标准方法,对5个番石榴品种(‘红宝石’、‘粉红蜜’、‘西瓜’、‘水蜜’、本地种)果实的外观和营养成分进行测定,采用顶空气质联用(HS-GC-MS)技术对5个品种果实的香气成分进行测定。结果表明,不同品种果实外观及营养成分差异明显。‘水蜜’的果形指数最低,果实扁圆形,种籽最少;大多数糖类物质(总糖、还原糖、蔗糖等)、糖酸比、总酚含量最高;果糖、VC和总黄酮含量位居第2;总酸、脂肪、粗纤维、灰分含量最低。主成分分析表明,‘水蜜’作为鲜食水果的食用品质最高。己醛和石竹烯是红肉型品种的特征风味物质,3-羟基-2-丁酮是白肉型品种的特征香气成分。     

Superoxide dismutase and catalase activities in apple fruit during ripening and post‐harvest and with special reference to ethylene

Oxidative stress is involved in many biological systems, among which are fruit ripening and senescence. Free radicals play an important role in senescence and ageing processes. Plants have evolved antioxidative strategies in which superoxide dismutase (SOD, EC 1.15.1.1) and catalase (CAT, EC 1.11.1.6) are the most efficient antioxidant enzymes, influencing patterns of fruit ripening. Variations in total SOD and CAT activities were determined at regular intervals during ripening and senescence in on‐tree and cold‐stored apple fruits of the cultivars Fuji and Golden Delicious. In all fruits, internal ethylene concentration was also measured. The results suggest that the onset of ripening, signalled by ethylene burst, is closely related to SOD and CAT activities. In on‐tree fruits the climacteric peak in ethylene was associated with the peaks of SOD and CAT activity in both cultivars. Quite different results were obtained in cold‐stored fruits: Ethylene concentration increased in both cultivars during the storage. CAT activity doubled in both cultivars. SOD activity decreased in Golden Delicious and peaked in Fuji.     

硬肉桃果实成熟前后钙含量和钙ATP酶活性的变化及其与果实硬度的关系

以硬肉桃新品种‘双久红’果实为试材,以常规优良品种‘川中岛白桃’为对照,分别研究了成熟前20d和成熟后20d内两品种果实中钙含量和Ca^2＋-ATP酶活性变化以及它们与果肉硬度关系的结果表明：‘双久红’果实的总钙和Ca^2＋含量从成熟前15d开始极显著高于同期‘川中岛白桃’的,两者与果实硬度变化呈极显著相关（P〈0．01）,随着果实的成熟两者均呈下降趋势,Ca^2＋-ATP酶的调控能力也逐渐减弱,但‘双久红’果实中的Ca^2＋-ATP酶活性比‘川中岛白桃’高一些。     

茄子体内α-茄碱的含量检测及分布特点

以不同品种的茄子（Solanum melomgena L.）为试材,采用超声波提取技术和高效液相色谱法对茄子不同器官、不同颜色、不同采收时期和不同成熟度的果实及果实不同部位中α-茄碱进行提取和测定,旨在明确茄子体内α-茄碱的含量及分布特点。结果表明,茄子不同器官中,果实中α-茄碱含量最高;紫茄品种α-茄碱含量显著高于绿茄;不同时期采收的果实中以门茄中α-茄碱含量最高;未成熟茄子果实中α-茄碱含量显著高于成熟的茄子果实;各茄子品种果肉中α-茄碱含量显著高于果皮和果蒂。     

水杨酸（SA）对果实成熟的影响

水杨酸是一种天然抑制剂,对植物有多种多样的作用,新近研究报道,它是乙烯生物合成的一种新的抑制剂。本文用水杨酸处理番茄、苹果、梨等果实,储藏在室温下,不时检查SA对果实贮存保鲜的影响。其结果表明SA处理的果实,PG活性比对照低,而硬度大,抗病力强。番茄,苹果和梨的无病好果率比对照果提高10％以上。上述结果证明,用SA处理绿熟番茄及梨和苹果,能有效保存果实新鲜,增强抗病力和延长货架的寿命。     

Role of phosphoenolpyruvate carboxylase in organic acid accumulation during peach fruit development

The synthesis of organic acids was studied during fruit development of two peach ( Prunus persica L. Batsch) cultivars, Fantasia and Jalousia, having fruits with high and low organic acid content, respectively. The malate content was higher in cv. Fantasia than in cv. Jalousia at the end of the first rapid growth stage (50 days after bloom [DAB]). Malate and citrate contents were higher in Fantasia than in Jalousia during the second rapid growth stage (from 100 DAB to maturity). The expression of phospho enol pyruvate carboxylase (PEPC, EC 4.1.1.31), which is involved in organic acid synthesis, was studied during peach fruit development. PEPC mRNA levels, and protein levels on a total soluble protein basis, peaked at 23 and 108 DAB in Fantasia. In Jalousia, they were very low at 23 DAB and reached levels similar to Fantasia at 108 DAB. For both cultivars, in vitro PEPC activity expressed on a dry weight basis was maximal at 24 DAB, decreased from 24 to 60 DAB, and then remained constant. The activity of peach fruit PEPC appeared extremely sensitive to malate (I_0.5 of 100 μ M for Fantasia and 65 μ M for Jalousia at pH 7.3) and low pH. PEPC may participate in the control of organic acid accumulation during fruit development in the normal-acid fruit of Fantasia. However, mechanisms other than organic acid synthesis might account for the differences in acidity between normal-acid and non-acid peach fruit.     

欧李果实发育期糖和酸组分及其含量的动态变化特性

以农大3号、农大4号、农大5号3个欧李品种为材料,测定果实发育过程中各组分糖、酸及总糖、总酸的含量,以明确欧李果实糖酸积累的动态变化特性.结果显示:(1)3个欧李品种果实成熟期糖含量、酸含量及糖酸比存在明显差异,其中农大3号品种的总糖含量最高,总酸含量最低,糖酸比值最高.(2)成熟期3品种各糖组分中均以果糖含量较高,葡萄糖和蔗糖含量较低,山梨醇含量微量;酸组分中均以苹果酸为主,柠檬酸少量.(3)3个品种果糖、蔗糖、葡萄糖、山梨醇含量在整个果实发育期均呈持续增加态势,并以果糖积累为主;农大3号果糖含量在8周后增幅明显高于另2个品种,且一直保持到果实成熟;3个品种蔗糖含量的变化趋势相近,在前期和中期增加缓慢,接近成熟的2～3周则迅速增加并占整个发育期积累量的70%以上.(4)3个品种酸含量的变化趋势较为相似,苹果酸和柠檬酸在果实发育的前期和中期含量均较低,在果实发育后期迅速增加,但接近果实成熟时又大幅下降.研究表明,果糖与苹果酸的含量及其动态变化是影响欧李果实糖酸比、决定果实风味的主要因素.     

桃果实不同发育时期细胞内糖酸分布对甜酸风味的影响

为了解桃果实发育过程中细胞内糖酸的分布、变化规律对果实甜酸风味的影响,采用区室分析方法研究了‘白凤’桃(Prunus persica‘Hakuho’)果实不同发育时期细胞内糖酸组分、含量及其分布对甜酸风味的影响。结果表明,成熟果实中(花后100 d)可溶性糖(蔗糖、葡萄糖、果糖和山梨醇)在液泡、细胞质和细胞间隙中的含量分别为27.3、11.6、9.0 mg/g,有机酸(苹果酸、柠檬酸、奎宁酸和莽草酸)含量为2.09、0.94、0.35 mg/g;未成熟果实中(花后60 d)可溶性糖在液泡、细胞质和细胞间隙中的含量分别为0.97、2.2、2.3 mg/g,有机酸含量为0.25、0.44、0.82 mg/g。‘白凤’桃果肉细胞内不同的糖酸分布对成熟果实的甜酸风味具有显著影响,而对未成熟果实影响较小。成熟果实中糖酸在液泡、细胞质和细胞间隙三者之间的分布差异可能是导致果实甜度变化的主要原因。     

Parthenocarpy of watermelon cultivars induced by γ-irradiation

We found that diploid seedless watermelon can be produced by pollination with partially functional pollen, which was irradiated with γ-rays at the doses of 600 and 800 Gy. The diploid seedless fruits were almost similar to normal fruits in development from pollination to maturity. The number of empty seeds in the diploid seedless fruits varied among the cultivars used. Seedless watermelon cultivars revealed a significant increase in total sugar and carotenoids (lycopene and gb-carotene) contents. The pollen tubes of the pollen subjected to γ-radiation penetrated normally into the synergid, and sperm cells were discharged. Subsequently, the egg nucleus and sperm nucleus became attached to each other in the egg cell and a globular embryo was formed. However, the embryo failed to differentiate the tissues and degenerated. It is suggested that seedless watermelon fruits induced by γ-rays are characterized by increasing yield and better quality due to higher carotenoid and total sugar contents and fruit weight. In some cultivars, there is a tendency in decreasing the thickness of rind.     

罗汉果果实生长发育与内含物变化的研究

罗汉果开花授粉后果实体积不断地增大。纵径在授粉后1至3天生长最快,以后逐渐减慢:横径以授粉后9至15天生长最快,30天果实体积停止增长。果实生长发育过程中,干物质含量由低到高变化,总糖含量由低到高不断增加,但还原糖与非还原糖含量的变化有所不同,维生素C含量在生长发育前期最高,随果实发育,其含量逐渐下降。