番茄绿熟期果实硬度与果皮结构及果胶含量的关系

比较硬果型番茄TS330 和软果型番茄A57 不同发育阶段的果实硬度变化,结果表明：绿熟期、转色期、红熟期TS330 果实硬度均显著高于A57,其中绿熟期果实硬度差异最大。绿熟期TS330 果皮细胞壁厚度、细胞致密度（单位厚度的细胞层数）和果胶含量显著高于A57。TS330、F₁（TS330×A57）、A57 绿熟期果实硬度依次为26.86、21.09、19.11 kg ·cm^-2。番茄果实硬度与果皮细胞致密度（相关系数0.96）、果胶含量（相关系数0.99）密切相关。TS330×A57 的F₂ 果实硬度 趋向正态分布,表明果实硬度受多位点控制。     

DEHP在冬瓜果皮和果肉的累积差异及与果皮蜡质组成的关系

通过气相色谱-质谱联用的方法研究了不同批次广东黑皮冬瓜邻苯二甲酸二(2-乙基己基)酯(DEHP)在果皮和果肉的含量差异,同时研究了累积DEHP最高和最低批次冬瓜果皮蜡质的组成.结果表明:不同批次冬瓜DEHP在果皮和果肉中的含量均达显著性差异(P＜0.01),在果皮中含量从( 12.603±0.7860)～(37.628±1.7326) mg/kg(鲜重),而果肉含量从(3.642±0.2010)～(6.474±0.1831)mg/kg(鲜重).保留时间短的蜡质在低累积DEHP批次冬瓜果皮中含量相对较多,保留时间长的蜡质在高累积DEHP批次冬瓜果皮中含量相对较多.说明蜡质的组成差异可能导致了不同批次冬瓜DEHP累积的差异.     

钙处理对‘南果梨’果皮微观结构、蜡质成分及香气释放的影响

为研究钙处理对‘南果梨’果实果皮微观结构、表皮蜡质组成和香气释放的影响,在‘南果梨’果实商熟期前15 d喷施0.04 kg·L^-1氯化钙,喷水作为对照,在商熟期和后熟5 d后用扫描电子显微镜和透射电子显微镜分别观察果皮微观结构、细胞排列,并用质谱测定表皮蜡质组成,用气相色谱—质谱法(GC–MS)测定挥发性香气物质含量。结果表明:钙处理果实果皮蜡质层较对照脱落更多,但果点比对照完整,果实表层细胞间隙大于对照。‘南果梨’果实表皮蜡质化学组分包括脂肪酸、脂肪醇、酯类、烷烃、烯烃、醛类和酚类,其中以脂肪酸、脂肪醇、烷烃、醛类为主,钙处理果实果皮蜡质中酯类、脂肪酸、醛类的相对含量显著高于对照(P <0.05)。钙处理果实挥发性香气物质总含量在商熟期和后熟5 d时总含量分别为3 959.75和6 676.80 ng·g^-1,比对照提高20.92%和24.16%。以上表明钙处理通过改变‘南果梨’果实果皮的微观结构和蜡质成分,增加了其香气的释放。     

叶片微形态结构特征与柑桔溃疡病抗性的关系

为了研究叶片微结构特征与柑桔溃疡病抗性的关系,选择对柑桔溃疡病具有高抗(罗浮金柑)、抗(新生系3号椪柑)、耐(纽荷尔脐橙)和高感(星路比葡萄柚)特性的4个品种为试材,在室内涂抹接种验证抗病性的基础上,采用扫描电镜及树脂包埋半薄切片等技术对成熟叶片的解剖结构及下表皮进行观测,并采用细菌分离法测检各品种健康叶片浸泡接种病菌侵入数量.结果表明:4个品种对柑桔溃疡病抗性差异明显;叶片浸泡接种病菌侵入数量与品种抗性密切相关,依次为星路比葡萄柚＞纽荷尔脐橙＞新生系3号椪柑＞罗浮金柑;不同品种的气孔密度、气孔大小、叶片厚度、栅栏组织厚度、海绵组织厚度和下皮层厚度存在差异,但是只有气孔密度与抗性之间能呈现出有规律的对应关系;气孔密度可作为柑桔植株抗柑桔溃疡病早期选择的辅助形态指标.     

薄皮甜瓜组织结构、纤维素及果胶含量与果实感官品质的关系

以玉美人、龙甜3号、高甜黄金道、日本甜宝和香沙蜜5个薄皮甜瓜品种为试材,鉴定了成熟期各品种感官品质,观察了石蜡切片,并测定了果实中纤维素和可溶性果胶含量。结果表明:薄皮甜瓜表皮细胞切面小,表面积大,薄壁细胞递增快,近圆形细胞较多,且大小均匀,则果实感官品质好。同时,成熟果实中纤维素含量在0.24%～0.28%之间,可溶性果胶含量低,利于感官品质的提高。薄皮甜瓜感官品质与成熟果实中组织结构、纤维素和果胶含量关系密切。     

Relationship between light,fruit and leaf mineral content with albinism incidence in strawberry (Fragaria x ananassa Duch.)

A study was conducted in strawberry to establish a relationship between shading, mineral nutrient of leaves and fruits with albinism incidence. Plants grown under shade produced albino fruits in higher proportion than those grown in open fields. Similarly, plants under shade produced smaller sized fruits and have lower fruit yield. Among cultivars, Etna had highest incidence of albinism (49.6%) and Sweet Charlie the lowest (14.4%). Dry matter content (%), concentration of five major nutrients, viz. N, P, K, Ca, Mg, S and N:Ca and K:Ca nutrient ratios did not differ significantly in the leaves of plants producing normal or albino fruits. However, in contrast, the concentration of K was notably higher (1.97 mg g⁻¹ fresh tissue weight) and that of Ca was lower (0.098 mg g⁻¹ fresh tissue weight) in albino fruits than normal ones. Consequently, the ratios of N:Ca (11.34) and K:Ca (20.08) were higher in albino fruits than normal ones. Cultivars also differed widely in respect to dry matter (%), mineral content and nutrient ratios. Thus, it appears that lower light intensity favours the development of albinism in strawberry, and it seems that calcium is not the basic cause of albinism, but increased vigour associated with overuse of N and K might be positively associated with it.     

Effect of GA3, Planofix (NAA) and Ethrel on granulation and fruit quality in ‘Kaula’ mandarin

The effect of GA₃ 15 mg l^?1, Planofix (NAA = 1-naphthalene acetic acid) 300 mg l^?1 and Ethrel 250 mg l^?1 on granulation and fruit quality in ‘Kaula’ mandarin (Citrus recticulata Blanco) was studied during 1975–1976. Three sprays of Planofix reduced the incidence of granulation to 30.7% from 62.7% in control. Three sprays of GA₃ were almost equally effective (31.3% granulation). These treatments also improved the fruit quality and gave the highest fruit weight, pulp percentage, juice, T.S.S., reducing and non-reducing sugars and ascorbic acid, and the lowest acidity, peel and rag. In both these treatments (3 sprays of GA₃ or Planofix) the T.S.S. was 9.3% (8.1% in control). The application of 3 sprays of Planofix 300 mg l^?1 or GA₃ 15 mg l^?1 is, therefore, considered to be successful in reducing the granulation in this cultivar of mandarin.     

The effect of conditions of storage on the respiration of apples. V. The relationship between temperature,rate of respiration,and composition of the internal atmosphere of the fruit

Change of rate of production of CO₂ leads to change in the composition of the internal atmosphere of apple fruits, and therefore the gross effect of temperature is a complex phenomenon which involves change in other parameters of the cellular environment.

An attempt has been made to determine the effect of temperature alone on the cellular rate of respiration, but it does not appear to be possible to do this for a bulky organ.

Over the range from 0° to 12 °C, the concentration of CO₂ in the intercellular spaces of an apple varied directly with the rate of production of CO₂, thus satisfying Fick’s law. Temperature appeared to have no effect on the porosity of the skin.     

Changes of physicochemical quality,phenolics and vitamin C content in hardy kiwifruit (Actinidia arguta and its hybrid) during storage

The effect of storage and the stage of maturity of hardy kiwifruits on the physicochemical quality, phenolics (TPC) and ascorbic acid content (AAC), as well as antioxidant activity (AA) were studied in this work. The phenolic compounds in hardy kiwifruits were separated and characterized by HPLC. The investigation was carried out on the two cultivars of Actinidia arguta – ‘Weiki’, ‘74-49’ and the hybrid of A. arguta and Actinidia purpurea (‘D14’). Fruit firmness rapidly decreased and the soluble solid content (SSC) increased for all cultivars during the first 14 days of storage at 1 °C. The AAC and TPC in vine ripe fruits were similar to the ones of the fruits of storage harvest maturity (8–10% SSC). AA content depended on the clone and either decreased during storage or remained almost unchanged. There was an increase in TPC after 7 days of keeping the fruits in a cold store chamber at the temperature 1 °C, but a longer period of storage caused a decrease in these compounds. AA (at harvest for storage purposes) was higher than that of vine ripe fruits and the ability to absorb free radicals slightly decreased during storage. There was a strong correlation between AAC, TPC and AA. That means that phenolics and vitamin C affect the antioxidant activity of hardy kiwifruits.     

Induction of lateral branches in tree fruit nursery stock with propyl 3-t-butylphenoxy acetate (MB 25, 105) and Promalin (GA4+7 + 6-benzyladenine)

Sprays with 250–2000 mg l^?1 propyl 3-t-butylphenoxy acetate (MB 25,105) and 250 and 500 mg l^?1 GA₄₊₇ + 6-benzyladenine (Promalin) were applied to scion growth of first nursery trees of ‘Bartlett’ pear (Pyrus communis L.), ‘Bing’ cherry (Prunus avium L.) and ‘Oregon Spur II Delicious’ apple (Malus domestica Borkh.) to stimulate lateral branching in the nursery. Most treatments significantly increased branching compared to untreated controls. Combination sprays of the two chemicals were usually better than either used alone. Chemical treatment usually produced greater branching and wider branch angles than mechanical heading. Both chemical and mechanical treatments reduced tree height and caliper, but the decrease was not always statistically significant.     

Role of 24-epibrassinolide in mitigating the adverse effects of salt stress on stomatal conductance,membrane permeability,and leaf water content,ionic composition in salt stressed strawberry (Fragaria × ananassa)

In order to study the effect of brassinosteroids on the amelioration of the inhibitory effect of salinity on strawberry plants, a short-term experiment was conducted in greenhouse to test different concentrations of 24-epibrassinolide (24-EBL) (0.0, 0.5, and 1 μM) by foliar application on some agro-physiological properties, such as shoot dry weight, and root dry weight, stomatal conductance (SC), leaf relative water content (LRWC), leaf chlorophyll reading values (LCRV) and membrane permeability (MP) of strawberry ‘Fern’ and ‘A6’ cultivars irrigated with salt water (35 mM NaCl). 24-EBL solutions were applied twice during late afternoon hours with 7 d intervals using a hand-held sprayer. Plant shoot dry weight, root dry weight, SC, LRWC and LCRV were reduced by 29–33%, 45–15%, 71–55%, 11–13%, and 12–13% for ‘A6’ and ‘Fern’ cultivars at 35 mM (without 24-EBL applied), respectively, as compared to the nonsaline treatment, but MP increased 40% and 12%. An exogenous supply of 24-EBL was found to be successful in alleviating of the inhibitory effects of salt stress on plant growth parameters and nutrient contents. 24-EBL (1 μM) application under saline condition significantly increased shoot and root dry matter, SC, LRWC and LCRV of plants, and alleviation effects of 1 μM 24-EBL application was 20%, 15%, 122%, 5.8%, and 10.9% for ‘A6’ and 47%, 8.0%, 83%, 33.3% and 6.0% for ‘Fern’ cultivars, respectively. Macro-micro element content of plant leaf and root increased with increase 24-EBL except for Na under salinity stress. These results support the view that supplementary 24-EBL application can overcome the effects of salinity stress on plant growth and growth parameter under saline conditions.     

Foliar fertilization of peach (Prunus persica (L.) Batsch) with different iron formulations: Effects on re-greening,iron concentration and mineral composition in treated and untreated leaf surfaces

A trial to assess the effects of applying several Fe-containing formulations on Fe-deficient (chlorotic) peach leaves was carried out under field conditions. Solutions consisting of an Fe-containing compound (FeSO₄·7H₂O, Fe(III)–citrate, Fe(III)–EDTA, Fe(III)–DTPA or Fe(III)–IDHA) and one of five different surfactant treatments (no surfactant, an organo-silicon, an ethoxylated oil, a non-ionic alkyl polyglucoside and a household detergent) were applied to one half of the leaf via dipping, first at the beginning of the trial and then after 4 weeks. The re-greening of treated and untreated leaf areas was estimated with a SPAD apparatus, on a weekly basis, during 8 weeks. At the end of the experimental period, leaves were detached, and tissue Fe, N, P, K, Ca, Mg, Mn, Zn and Cu concentrations were determined in Fe-treated and untreated leaf areas. Treatment with Fe-containing solutions always resulted in leaf chlorophyll (Chl) increases, which however significantly depended on the Fe-source, the surfactant-type and the combination between both formulation components. Untreated leaf zones experienced a Chl increase only in some cases, and this depended on the type of surfactant used. Iron application significantly increased the Fe concentration of treated and untreated leaf areas, especially with some formulations. Foliar treatment with Fe-containing solutions induced significant changes in the concentration of several nutrients as compared to those found in Fe-deficient peach leaves, with changes being similar in treated and untreated leaf areas, although in some elements the extent of the changes was of a different magnitude in both materials. This indicates that some leaf mineral composition changes typical of chlorotic leaves are dependent on leaf Fe concentration rather than on leaf Chl levels. Results obtained are relevant to help understand the factors involved in the penetration and bioavailability of leaf-applied Fe, and to assess the potential of foliar Fe fertilization to control Fe deficiency in fruit trees.