Evaluation of Physico-Chemical Properties and Bioactive Compounds of Some Iranian Pomegranate Cultivars

Persia is one of the main origin centers of pomegranate; hence, a diverse germplasm has evolved in the area over the past centuries. This study was conducted to evaluate the physico-chemical properties of fruits of ten Persian pomegranate cultivars. The plants used for this experiment had been collected from different parts of Iran and were established in a repository. Wide variations in the main properties of the ripe fruits of the cultivars were observed. The size, weight, skin thickness and weight, and juice content of the fruits were within the range of 55.14–71.76 mm, 98.55–199.40 g, 1.07–3.93 mm, 28.96–66.95 g, and 2.00–89.33 ml, respectively. Seed weight, Aril numbers, fresh and dry weight of 100 arils were 33.80–72.90 g, 170.70–570.30, 23.16–42.82 g, and 17.22–33.87%, respectively. The levels of total anthocyanin, total soluble solids (TSS), titrable acidity (TA), ascorbic acid, total phenolics, electrical conductivity, and TSS/TA ratio were ranged between 5.91–180.70 mg/100 g, 9.35–13.93 °Brix, 0.16–2.28%, 7.15–1061 mg/100 ml, 3578–5108 mg/100 g, 2.51–4.93 dS/m, and 4.09–80.34, respectively. The results emphasized on the role of plant genotype on fruit taste parameters, bioactive compounds, and yield. The variations in the fruits indicated differences in nutritive quality, which may satisfy diverse consumer acceptance in different areas. Moreover, it provides great opportunities for improving crop yield and quality.     

Variety-specific responses of lettuce grown under the different-coloured shade nets on phytochemical quality after postharvest storage

This study illustrates the effects of light quality as influenced by photo-selective shade nets (red, yellow, and pearl with 40% shade) and the widely used commercial black net (25% shade) on overall retail quality and phytochemical contents of three lettuce (Lactuca sativa L.) varieties (two green varieties, Ashbrook and Aquarell, and a red variety, Exbury) at after postharvest storage. Variety-specific responses were observed with respect to different coloured shade nets with regards to the accumulation of β-carotene, ascorbic acid, flavonoids (kaempferol, isorhamnetin, quercetin, myricetin, anthocyanin), and antioxidant activity at harvest. Growing var. Ashbrook under the pearl net improved the ascorbic acid and myricetin contents after postharvest storage. Var. Exbury (red) produced under the black net showed higher retention of ascorbic acid, and anthocyanin contents after postharvest storage. Also pearl net production improved the β-carotene content after postharvest storage in var. Aquarell. All lettuce types produced under the pearl nets showed less weight loss, and overall acceptance after postharvest storage. Spectral quality under the shade nets enabled us to improve the phytochemical content and antioxidant properties in light-sensitive varieties Ashbrook Aquarell and Exbury, during winter season.     

钾锌营养对水培生菜生长、产量和品质的影响

通过增施钾肥、锌肥和钾锌同增,研究钾锌肥对生菜生长、产量和品质的影响,以期为生菜优质、高效生产模式下的施肥管理提供理论支撑。结果表明,钾、锌肥对生菜生长均有促进作用,钾锌同增效果最显著,较对照株高显著增长23.71%;钾肥和锌肥均可提高生菜可溶性蛋白和可溶性糖含量,钾锌同增处理的可溶性蛋白和可溶性糖含量较对照分别增长23.82%、115.54%;但维生素C含量会因为钾水平过高而降低,对照较增施钾肥处理显著增长68.30%,锌肥对生菜维生素C含量有促进作用;钾、锌肥均可提高生菜硝酸还原酶活性,降低硝酸盐含量,且钾锌肥互作的协同效果更佳,较对照高42.78%;钾、锌肥通过影响生菜叶绿素的合成进而影响生菜产量,钾锌同增处理生菜产量最高,较对照高77.93%,其次是增钾处理,对照处理产量最低。     

不同施肥处理对乌塌菜产量和品质的影响

以乌塌菜为试材,通过田间小区试验研究不同的施肥处理对乌塌菜产量和品质的影响。结果表明:有机肥的施用和不施任何肥料的空白相比,产量增加125%,氮肥配施对乌塌菜生产有明显的增产效果;配施氮肥使乌塌菜硝酸盐含量明显增加,而维生素C含量明显降低;配施磷肥可以降低乌塌菜硝酸盐含量。     

Fruit quality in ‘Cripp's Pink’ apple,especially colour,as affected by preharvest sprays of aminoethoxyvinylglycine and ethephon

‘Cripp's Pink’ apple grown in Western Australia often develops poor colour at commercial harvest resulting in economic losses. To determine if fruit colour could be improved without advancing ripening, ‘Cripp's Pink’ apple fruit on trees were sprayed with aminoethoxyvinylglycine (AVG) alone, ethephon alone, or AVG followed by ethephon. The experiments were conducted at two different locations in Western Australia in 2002 and 2003. Fruit sprayed with AVG alone had retarded colour development at harvest. However, ethephon applied after AVG enhanced percent red blush, anthocyanin concentration and reduced chlorophyll concentration in the fruit skin in both locations. These fruit had similar colour to those treated with ethephon alone. Internal ethylene concentration and fruit firmness were unaffected by the different treatments in 2002. However, in 2003 AVG with or without ethephon reduced internal ethylene concentration and maintained firmness compared to ethephon alone. In conclusion, AVG treatment alone delayed colour development and ripening of ‘Cripp's Pink’, while AVG application 5 weeks before harvest followed by an ethephon application 2 weeks later enhanced red colour at commercial harvest. This is, therefore, an effective tool for improving colour of ‘Cripp's Pink’ apples at commercial harvest without adversely affecting other fruit quality attributes.     

外源水杨酸对韭菜硝酸盐累积及还原同化的影响

 针对韭菜生产中硝酸盐累积问题,研究了叶面喷施水杨酸(SA)对韭菜硝酸盐累积及还原同化的影响。在不同氮素水平下,叶面喷施3.0 mmol·L^-1SA后6～9 d可明显降低韭菜叶片硝酸盐含量15.9％～21.6％,而当SA水平达到10.0 mmol·L^-1时会加重硝酸盐的积累。叶面喷施3.0 mmol·L^-1SA后9 d,韭菜叶片硝酸还原酶(NR)和谷胺酰氨合成酶(GS)活性分别比对照增加了48.9%和40.3％、净光合速率(Pn)和可溶性蛋白含量分别提高了43.4%和21.3％;同时,韭菜叶片谷氨酸草酰乙酸转氨酶(GOT)活性和谷氨酸丙酮酸转氨酶(GPT)活性也均有增加。因此,叶面喷施的外源水杨酸显著提高了氮还原动力泵NR活性以及氮同化动力泵GS活性,同时调动光合作用和转氨作用的积极协同配合,促进了硝态氮转化为游离氨基酸和可溶性蛋白,减少了硝酸盐进入液泡贮积。     

酚类物质对东北山樱生长及呼吸关键酶的影响

 以东北山樱（Cerasus sachalinensis Kom.）幼苗为试验材料,研究了根施酚类物质对羟基苯甲酸和香豆素对其生长和呼吸关键酶的影响。结果表明,低浓度的香豆素显著促进东北山樱幼苗生长,提高幼苗光系统Ⅱ（PSⅡ）最大光化学效率、呼吸底物含量、中间产物丙酮酸含量和苹果酸脱氢酶（MDH）活性,不影响糖酵解途径（EMP）和磷酸戊糖途径（PPP）关键酶活性;高浓度香豆素抑制生长,降低PSⅡ最大光化学效率、淀粉含量、异柠檬酸脱氢酶（IDH）和磷酸果糖激酶（PFK）活性。对羟基苯甲酸及其与香豆素的混合溶液在3个作用浓度（0.1、1.0和10 mmol · L-1）下均不同程度地抑制幼苗生长,降低柠檬酸含量,促进PPP关键酶活性提高。低浓度对羟基苯甲酸对幼苗PSⅡ最大光化学效率和呼吸底物含量无影响,但提高丙酮酸含量、己糖激酶（HK）、丙酮酸激酶（PK）和琥珀酸脱氢酶（SDH）活性,降低IDH、MDH活性;高浓度对羟基苯甲酸使幼苗PSⅡ最大光化学效率、呼吸底物和中间产物含量、PFK、PK、IDH、MDH活性下降,HK活性提高。     

一氧化氮处理对韭菜维生素C含量的影响

以地产农家新鲜韭菜为试材,研究了常温、常压下用硝普钠溶液处理对韭菜贮藏保鲜效果的影响。结果表明:选择不同浓度的硝普纳(SNP)溶液,处理韭菜时间的长短对其保鲜效果的影响各不相同,1.0μmol/L SNP、浸泡1.5h对延缓维生素C含量下降的作用最大。说明适宜浓度外源NO处理能够降低延缓芹菜氧化衰老进程,对采后芹菜有显著的保鲜效果。     

成熟期土壤含水量对‘北玫’葡萄果实中酚类物质积累的影响

以‘北玫’葡萄为试材,采用HPLC法测定葡萄果实中单体酚类物质的含量,研究了成熟期不同土壤含水量处理对果实品质和酚类物质含量的影响,以期为贺兰山东麓酿酒葡萄产区酿酒葡萄品质的提高提供参考依据。结果表明:降低土壤含水量处理可以提高果实中可溶性总糖含量,降低可滴定酸含量。50%~60%相对土壤含水量处理极显著提高了采收期果实中甲基花青素、花翠素葡萄糖苷的含量,显著提高了二甲花翠素的含量;总花色苷和单宁含量极显著高于CK,总酚含量也显著高于CK。对采收期果实中酚类物质指标进行主成分分析,50%~60%相对土壤含水量处理综合得分最高。     

Expression of PPO and POD genes and contents of polyphenolic compounds in harvested mango fruits in relation to Benzothiadiazole-induced defense against anthracnose

Mango is susceptible to decay caused by pathogen infection during storage and transport. Chemical fungicides have been the major weapons against postharvest fungal diseases, but they have caused increasing public resistance. BTH does not have anti-microbial properties, but it induces systemic acquired resistance in plants. Here the relationship between BTH-induced disease resistance in harvested mango fruits and expression of PPO and POD genes, together with contents of total phenolic compounds (TPC), were investigated. BTH treatment reduced disease indices and lesion diameter. Compared with the control, BTH increased TPC, up-regulated gene expression and enhanced enzymes activities of PPO and POD during the latter period of storage life, suggesting that enhanced gene expression of PPO and POD played an important role in BTH-activated defense response of mango fruits and that the up-regulation of the two genes were related to the accumulation of TPC. This study also showed that BTH-induced resistance in harvested mango fruits could differ with varieties.     

黄瓜叶面喷施硅肥对果实糖分和维生素C积累及相关酶的影响

研究了黄瓜叶面喷施硅肥对其生长、产量、果实糖分、维生素C及相关酶活性和基因表达量的影响。结果表明：叶面喷施硅肥显著促进了黄瓜生长,增加了单株产量,提高了果实中碱性转化酶（NI）、蔗糖磷酸合成酶（SPS）、蔗糖合成酶（SS）及半乳糖内脂脱氢酶（GaILDH）活性,提高了果实果糖、葡萄糖和维生素C含量。其中,1.420 g · L^-1单硅酸处理效应最显著,其果糖、葡萄糖和维生素C含量分别较对照高13.79%、18.08%和75.11%。实时荧光定量PCR分析表明,叶面喷施单硅酸的黄瓜果实碱性转化酶–3（NI-3）、蔗糖磷酸合成酶（SPS）和半乳糖内脂脱氢酶（GaILDH）基因表达量显著提高。     

叶面喷施氯化钙对海南高温季节水培生菜生长生理的影响

为了探索高温水培环境下叶面喷施氯化钙对生菜生长生理的影响,以辛普森精英散叶生菜为材料,在35℃/25℃(昼/夜)下设置4个氯化钙浓度1、3、5、7 mmol·L-1处理,以清水为对照.结果表明,与对照相比,5 mmol·L-1氯化钙处理生菜最大叶宽、地上部鲜质量、地下部鲜质量和抗氧化酶活性均显著提高,丙二醛含量和叶片相...     

亚硫酸氢钠对白菜叶片硝酸盐还原及光合能力的影响

 对日光温室内栽培的五叶一心白菜分别叶面喷施2、5、10 和15 mmol · L^-1 亚硫酸氢钠（NaHSO3）,以喷施清水为对照,分别在处理后0、4、8、12 和16 d 测定植株生物量、叶片的硝酸盐含量（NO₃^-）和硝酸还原酶（Nitrate reductase,NR）活性,同时测定叶片的光合参数和叶绿素荧光参数。结果表明,10 mmol · L^-1 NaHSO₃ 处理后12 d 时的效应最为显著,与对照相比,叶片NO₃^-含量降低44.85%,NR 活性提高51.26%,且株高和地上部干质量均明显增加;同时显著提高其净光合速率（P_n）、羧化效率（CE）、最大羧化速率（V_cmax）、PSⅡ的原初量子效率（Q）和最大电子传递速率（ETR_max）。由此说明,对白菜叶面喷施NaHSO3,一方面能够在一定程度上提高NR 活性,拉动氮素的还原同化,降低NO3-的累积;另一方面能够通过提高PSⅡ电子传递能力和羧化反应速率,促进光合碳同化效率,可在碳骨架和能量供应上拉动氮代谢的还原同化。     

套袋对桃果实成熟过程中酚酸类和类黄酮类物质积累的影响

 以‘晚蜜’桃为试材, 果实于盛花后75 d套袋、盛花后144 d除袋, 以未套袋果作对照, 应用HPLC - MS技术对果皮中酚酸类和类黄酮类物质进行了定性定量分析。在成熟果中分离、检测到了3种酚酸类物质, 8种黄酮醇类物质, 5种黄烷- 3 - 醇类物质和2种花色苷类物质。伴随果实成熟, 酚酸类和黄烷- 3 - 醇类物质的含量逐渐下降; 黄酮醇类物质在果实发育早期含量较高, 而后逐渐降低, 果实着色初期其含量骤然上升, 到成熟后期又急剧下降; 未套袋果在盛花后144 d已有花色苷积累, 套袋果除袋后果皮迅速合成花色苷。成熟期套袋果和未套袋果中的酚酸和黄烷- 3 - 醇类物质的含量没有差异, 但套袋果中花色苷类和黄酮醇类物质的含量显著高于未套袋果, 其中套袋果的花色苷含量为未套袋果的1174倍。试验表明, 酚酸类和黄烷- 3 - 醇类物质对光较敏感, 套袋显著抑制了这两类物质的合成, 但未影响成熟果中的含量, 套袋处理增加了成熟果中花色苷和黄酮醇的积累。桃果皮中的花色苷类物质代谢在果实发育早期向花色苷以外的各分支代谢方向进行, 果实着色初期同时积累黄酮醇和花色苷, 到成熟后期主要为花色苷的合成。     

Effects of cerium on the antioxidant defence system in the petals and the contents of pigments in the calyces of Rosa chinensis Jacq. cut flower

To study the role of cerium (Ce) in regulating the vase life of Rosa chinensis Jacq. cut flowers, the effects of cerium nitrate (Ce(NO₃)₃) on the activities of antioxidant enzymes, the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in the petals, and the contents of chlorophyll a, chlorophyll b and carotenoids in the calyces were investigated. The results showed that Ce(NO₃)₃ evidently enhanced the activities of peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST) and glutathione peroxidase (GPX), and evidently decreased the contents of MDA and H₂O₂ in the petals, compared with the control. Moreover, Ce(NO₃)₃ evidently increased the contents of chlorophyll a, chlorophyll b and carotenoids in the calyces. The results also showed that Ce(NO₃)₃ evidently increased the numbers of open flowers and decreased the numbers of wilted flowers. Our results suggest that Ce(NO₃)₃ extended the vase life of R. chinensis Jacq. cut flower by improving the antioxidant defence system in the petals and the contents of pigments in the calyces.     

不同微波渗糖工艺对低糖果脯维生素C保存的影响

研究了预处理方式、微波渗糖和干燥工艺等不同加工工艺对低糖果脯维生素C保存的影响,通过追踪测定各个工艺环节中维生素C保存的变化来寻求最佳微波渗糖工艺条件。结果表明,3种预处理方式在维生素C含量保存上以食盐预处理最好,微波预处理次之,热水漂烫预处理最差,质量分数2%的食盐溶液中浸泡30 min时果坯维生素C含量为1.083 0 mg.g-1,效果较好;微波渗糖时采用30%的微波火力渗糖20 min,后期干燥时选用60℃干燥6 h,与其他处理差异显著,果脯口感纯正,可以使多维营养得到最大程度的保存。     

Effect of organic and inorganic fertilizers applied during successive crop seasons on growth and nitrate accumulation in lettuce

A romaine-type lettuce (Lactuca sativa L.) cv. Corsica was cultivated during three successive crop seasons (late-spring, late-autumn and late-winter) in the same soil of an experimental greenhouse in S.W. Peloponnese, Greece. Seven long-term fertilization treatments were tested for their effect on plant growth and nitrate concentration in the external lettuce leaves. Treatments included: three different doses of organic fertilization (composted sheep manure) applied at the start of each crop season, three different doses of inorganic N fertilization applied via fertigation during each crop season, and a control treatment in which no fertilizer was applied. A drip irrigation system was used to water all plants. The highest nitrate levels were observed in the medium and maximum inorganic fertilization treatments (572–664 mg kg⁻¹) in all crop seasons. They were significantly higher compared to the respective organic fertilization treatments (253–435 mg kg⁻¹) and all other fertilization treatments (148–435 mg kg⁻¹). Crop season affected lettuce growth more than nitrate accumulation in the lettuce leaves: lettuce biomass production was the smallest and most uniform in the late-autumn season and did not respond to the fertilization treatments tested (ranging from 409 to 439 g plant⁻¹), while in the late-spring season biomass production was the highest and most variable (561–841 g plant⁻¹), it correlated with nitrate concentration in the leaves and in the medium and maximum inorganic fertilizer doses it significantly exceeded production from all other fertilization treatments (827–841 g plant⁻¹). Following the three crop seasons the residual availability of N, P and K was clearly enhanced in the soil receiving the organic compared to the inorganic fertilization. Nitrate concentration in lettuce leaves was far below the upper limits set by the European Commission in all fertilization treatments throughout the three crop seasons, a result attributed mainly to the sufficient level of light intensity and duration throughout the year in Southern Greece.     

不同贮藏方式对白萝卜中维生素C含量的影响

采用2,6-二氯靛酚滴定法测定不同贮藏方式下白萝卜中维生素C含量的变化,探讨不同贮藏方式对白萝卜中维生素C含量的影响.结果表明:白萝卜中维生素C在不同条件下随储藏时间的增加均呈下降趋势,维生素C在低温贮藏方式中损失最为缓慢.     

Effects of foliar application of some macro- and micro-nutrients on tomato plants in aquaponic and hydroponic systems

An aquaponic system was designed to investigate effects of foliar applications of some micro- and macro-nutrients on tomato growth and yield in comparison with a hydroponic system. Common carp, grass carp and silver carp were stocked in the rearing tanks at 15, 20 and 15 fish m⁻³, respectively. The fish were fed three times daily with a pellet diet containing 46% protein. Fourteen days old tomatoes seedlings were transplanted on to growth bed units of aquaponic and hydroponic systems after stocking of carp fish for 2.5 months in the rearing tanks. Foliar nutrients application began 30 days after transplantation. Eight treatments were used, untreated control, foliar application at the rate of 250 mL plant⁻¹ with 0.5 g L⁻¹ K₂SO₄, MgSO₄·7H₂O, Fe-EDDHA, MnSO₄·H₂O, H₃BO₃, ZnCl₂, and CuSO₄·5H₂O. Plants were sprayed twice a month. The results showed that biomass gains of tomatoes were higher in hydroponics as compared to aquaponics. Foliar application of K, Mg, Fe, Mn, and B increased vegetative growth of plants in the aquaponics. In the hydroponics, only Fe and B had positive effects on plant growth. Cluster number per plant in aquaponics was lower than in hydroponics treatments, but it increased with foliar application of elements. There was no difference in fruit number and yield between aquaponics and hydroponics grown plants in the control treatments. Except Cu, foliar spray of all elements significantly increased plant fruit number and yield in the aquaponics in order of: K > Fe > Mn > Zn > Mg > B. In the hydroponics, foliar application of K, Mg and Zn increased fruit number and yield of plants compared to control. These results indicated that foliar application of some elements can effectively alleviate nutrient deficiencies in tomatoes grown on aquaponics.     

Effects of ammonium sulphate and urea on NO3− and NO2− accumulation,nutrient contents and yield criteria in spinach

In this study, effects of ammonium sulphate (AS) and urea fertilizers on NO₃⁻ and NO₂⁻ accumulation, N, P, K, Ca, Mg, Fe, Cu, Zn, Mn contents and some yield criteria in spinach were investigated. Increments in nitrogen doses of AS and urea from 0 (control) to 150 kg N level ha⁻¹ increased NO₃⁻, NO₂⁻, total N contents and yield of spinach significantly, but usually decreased P, Zn and Mn contents. NO₃⁻ contents of spinach in 120 and 150 kg N ha⁻¹ of urea applications were higher than that of AS applications, while the NO₃⁻ contents of spinach in the lower application doses of AS were higher than that of urea applications. Increasing phosphorus availability in the higher doses of AS applications due to possibility of decreasing soil pH might be decrease NO₃⁻ accumulation in spinach by assimilating NO₃⁻ in protein form. NO₃⁻ and NO₂⁻ contents also gave the significant negative relationships with yield and P content in spinach. Decreasing micronutrient contents in spinach at the higher nitrogen doses might be due to dilution effect by increasing the plant biomass.