部分中国原产甜柿种质果实脱涩类型的鉴定

 以部分中国原产甜柿为试材, 通过对可溶性单宁含量测定和单宁细胞切片观察发现, 在果实接近成熟时, ‘罗田甜柿’、‘宝盖甜柿’、‘秋焰甜柿’ (鄂柿1号) 果肉中单宁细胞较小, 所占比例较低,可溶性单宁含量低于0.2%。因此确认供试中国甜柿种质属于完全甜柿。     

Phenolics concentration and antioxidant capacity of different fruit tissues of astringent versus non-astringent persimmons

Astringent and non-astringent persimmon fruits were compared for phenolic compounds, and their antioxidant capacity was studied in both peel and pulp. Fruits that were astringent generally had significantly higher concentrations of phenolics and greater capacities in either tissue. Pulp from astringent persimmons had more phenolics and higher capacity whereas the same was true for peels from non-astringent fruits. Among the methods tested for determining antioxidant capacity (ABTS, DPPH, FRAP, TBARS, SRSA, and HRSA), ABTS showed the best correlation with phenolics concentration while HRSA assays were not sufficiently sensitive to distinguish among genotypes or between fruit tissues. Therefore, we suggest that, for monitoring antioxidant capacity in persimmon, the ABTS method is most suitable.     

Strawberry Yellows in the Variety Auchincruive Climax

Summary

Fresh ‘Mavra Markopoulou’ fig fruits, harvested close to a fully ripe state in October, were stored at ?1?C in either air or 2% O₂ (balance N₂) for 29.d. During storage in air the rates of O₂ uptake and ethylene production declined substantially and fruit weight loss increased up to 2.1%. Storage in 2% O₂ resulted in further reduction of O₂ uptake and ethylene production rates. The effects of storage conditions on ripening indices at 20?C in air were also investigated. Fruit stored in air showed decreased firmness, ethylene production rate and flesh colour lightness, but no significant or consistent changes in respiratory quotient, O₂ uptake and CO₂ production rates, soluble solids content, titratable acidity and other colour changes in peel or flesh were observed. In contrast, storage in 2% O₂ resulted in decreased respiratory quotient (although values remained above 1), O₂ uptake and CO₂ production rates and prevented fruit softening, loss of green peel colour and decrease in flesh lightness during post-storage at 20?C. All fruit were stored successfully under the above conditions, but 2% O₂ is recommended for better firmness retention during storage for longer than 8.d.     

A modified chemiluminescence method for hydrogen peroxide determination in apple fruit tissues

Hydrogen peroxide (H₂O₂) is one of the important by-products produced by plant and fruit tissues during normal metabolism as well as under stress conditions. Evidence suggests that it is actively involved in many physiological activities in plants, including ripening, senescence and the development of disorders. Quantitative measurement of H₂O₂ in fruit has been a challenge due to variations in methodologies, and their sensitivities and interferences present in plant samples. Among the currently used methodologies, chemiluminescence (CL) is one of the most promising, due to its high specificity and sensitivity. However, direct application of CL methods developed for leaf analysis is not suitable for fruit, especially fruit peel tissues, possibly due to interfering compounds in fruit tissues. In this study, evaluation of the efficiency of removal of interfering compounds by PVP, PVPP and activated charcoal revealed that the PVPP is the most effective compound to remove the interference. This modified protocol can measure H₂O₂ content in apple peel and flesh tissues. ‘Red Delicious’ apple peel and flesh tissues were measured with amount of 1.48 and 1.03 μmol/g FW, respectively. The established protocol can also be used for a wide variety of tissues in addition to apple fruit, including strawberry tissues (fruit, calyx and leaves) and spinach leaves. This protocol was applied to determine the H₂O₂ concentration in 1-MCP and DPA treated apples after 5 months of storage, but no significant difference in H₂O₂ in those samples was found. Direct comparison of CL with a commercial hydrogen peroxide measurement OXIS kit was also made. The challenges to accurately assay H₂O₂ in fruit/plant tissue were discussed.     

气调贮藏对富士苹果采后生理 及果肉褐变的影响

气调对比试验结果表明气调贮藏可显著抑制富士苹果果实硬度的下降,减少内源乙烯含量,贮藏寿命达8个月,并可保持其品质;富士苹果果肉褐变的主要原因是CO     

Manganese nutrition of pepper (Capsicum annuum L.): Growth,Mn uptake and fruit disorder incidence

This research included two independent yet build up objectives: (i) to examine the effects of Mn concentration in the irrigation water on the yield and fruit quality of greenhouse-grown bell pepper exposed to heat stress; and (ii) to investigate in a laboratory experiment the role of Mn addition on oxidative and anti-oxidative components of fruit apoplast. The field experiment included four concentrations of Mn in the irrigation water (0, 0.2, 0.6 and 1.0 mg L⁻¹). The effect of Mn application rate on vegetative growth and total fruit yield was insignificant and despite low Mn concentrations in zero-Mn-fed plants, no visible foliar Mn symptoms were observed. A quadratic regression was obtained between high-quality fruit yield and Mn concentration in fruit. Based on the quadratic equation, maximum high-quality yield was obtained when fruit-Mn concentration approached 44 mg kg⁻¹ DW. The correlation also indicates that variations in high-quality yield could be explained by differences in fruit-Mn concentration. The combination of low-Mn nutrition and high air temperature which prevailed during the experiment (summer season) induced severe pale spots and blemished fruits; approximately 50% of fruits were infected in zero-Mn-fed plants. In a laboratory experiment with detached-fruit under high temperature the H₂O₂ concentration increased whereas ascorbic acid concentration decreased in the apoplast. In Mn-fed fruit the H₂O₂ concentration was attenuated and the activity of ascorbate oxidase was suppressed, with the result that apoplastic ascorbic acid concentration increased. In light of the known crucial role of Mn in enzyme activities and in detoxification of oxygen free-radicals, the pale spots might be related to Mn effect on oxidative stress-related apoplastic activities. The relationships between incidence of pale spots and plant-Mn concentration may support this hypothesis, but further research is needed to validate it.     

中国甜柿及其在世界甜柿基因库中的地位

 柿（Diospyros kaki Thunb.）原产中国,但绝大多数为完全涩柿,中国原产完全甜柿（简称中国甜柿）仅在湖北、河南和安徽三省交界的大别山区有分布。主要介绍中国甜柿的栽培历史、地理分布及其变异类型,并重点对其生物学特性、自然脱涩特点及遗传规律等进行总结;此外,还对中国甜柿在世界甜柿的起源与进化、自然脱涩机理和遗传改良研究中的价值进行了阐述。     

Physico-chemical changes during growth of persimmon fruits in the East Mediterranean climate region

Physico-chemical changes were monitored during growth of pollination variant non-astringent ‘Harbiye’ persimmon fruits (Diospyros kaki L.) grown at low or high altitude of the East Mediterranean Region of Turkey for two growing seasons (2001–2002 and 2002–2003). Fruit growth in diameter followed a typical double sigmoid curve, consisting of two rapid growth stages, stage I and stage III, separated by a period of slow growth (stage II) at both altitudes. The durations of stages I, II and III were 105–119, 21–35 and 21–42 days, respectively, at low and high altitude. ‘Harbiye’ persimmons showed significant decreases in soluble tannin concentration and total carotenoid content during stage I. At the end of stage I, ‘Harbiye’ persimmons became non-astringent. Stage II was characterized with slow growth, the beginning of acid degradation and a significant increase in total sugars, especially in the sucrose component. At end of stage II, the fruit began to turn yellow-orange, indicating the occurrence of colour break. The greatest increase in total soluble solids (TSS) content occurred in the final month before harvest during stage III when pronounced changes in skin colour and softening of fruits were observed. The 175 and 168 days after full bloom (DAFB) at low and high altitudes, respectively, are appropriate timing for harvest of the ‘Harbiye’ persimmon fruits in the East Mediterranean region. At these stages, ‘Harbiye’ persimmon fruits reached the best quality for consumers.     

Dynamische Absenkung des Sauerstoffgehaltes bei der Lagerung von Äpfeln

The influence of dynamic controlled atmosphere (DCA) with stepwise oxygen reduction in comparison to conventional ultra-low oxygen (ULO) storage (1.4% O₂) was examined with apples belonging to the cultivars ‘Elstar’, ‘Holsteiner Cox’ and ‘Boskoop’. In order to avoid fruit-damaging fermentation processes, regular analyses of fruit samples for fermentation products were carried out by headspace gas chromatography. The effect of storage methods on fruit quality was quantified after fruits had been removed from DCA or ULO conditions, and again after incubation in different post-storage conditions. The results showed significant improvements in fruit flesh firmness in ‘Holsteiner Cox’ and ‘Boskoop’ after removal from DCA storage and also after post-storage for three weeks under cold storage condition, as compared to ULO storage. The occurrence of skin spots on ‘Elstar’ apples was also significantly reduced by DCA storage.     

Apoplastic anti-oxidants in pepper (Capsicum annuum L.) fruit and their relationship to blossom-end rot

Summary

The aim of the present research was to study changes in the major anti-oxidative enzyme activities known to be associated with the apoplast, during the induction of blossom-end rot (BER) in bell pepper (Capsicum annuum L.) fruits grown under saline conditions. Pepper plants of the BER-sensitive cv. ‘Mazurka’ and less-sensitive cv. ‘Selica’ were grown under control, low- and high-salinity irrigation regimes. Fruits were harvested continuously and, after approx. 7 months under these conditions, BER symptoms started to appear (in the Spring season) and fruits were sampled for biochemical measurements. The intercellular washing fluid (IWF; apoplast fraction) of the fruit pericarp was prepared and enzyme activities in that fraction were determined. The results showed that production of reactive oxygen species (ROS) in the fruit apoplast was higher in ‘Mazurka’ than in ‘Selica’. Apoplastic peroxidase and superoxide dismutase (SOD) activities, and the concentration of ascorbic acid, increased during ‘Selica’ fruit development, whereas the concentration of H₂O₂ decreased. During the stage of rapid growth, when fruits are most susceptible to BER, apoplastic peroxidase activity was greatly enhanced in the healthy pericarp of BER-affected fruits compared to healthy fruits. Under saline conditions, apoplastic peroxidase and SOD activities, as well as ascorbic acid and H₂O₂ levels, increased in healthy fruits of the resistant cultivar ‘Selica’; whereas, in healthy fruit of the BER-sensitive cultivar ‘Mazurka’, apoplastic peroxidase activity decreased while the level of ascorbic acid increased, but to a much lesser extent than in ‘Selica’. SOD activity and H₂O₂ levels increased similarly in both cultivars with increasing levels of salinity. It is proposed that apoplast-associated peroxidase activity and ascorbic acid concentration are increased coordinately in response to salt stress and may be part of a protective anti-oxidation mechanism that determines cultivar sensitivity to BER.     

Varietal differences in phenolic content and astringency in skin and flesh of hardy kiwifruit resources in Japan

Varietal differences in the total phenolic content and astringency in the skin and flesh were determined among the cultivars and local collections of hardy kiwifruit with a ploidy variance found in Japan. The average values of the total phenolic content in the skin and flesh were 2.66 and 0.18 g 100 g⁻¹ FW, respectively. There were large varietal differences in the total phenolic content in the skin in the range of 1.3–5.0 g 100 g⁻¹ FW. Kochi (tetraploid), while Gassan and ‘Mitsuko’ (hexaploid) contained a larger amount of total phenolics. High astringency was found in Gassan, ‘Mitsuko’ and ‘Hoko’ (hexaploids) and Kochi. HPLC analysis showed that the major components of phenolics in the flesh were (+)-catechin, chlorogenic acid, rutin, (−)-epicatechin and quercetin.     

Physiological responses and quality attributes of Japanese pear ‘Kosui’ fruit kept in low oxygen atmospheres

Summary

Japanese pear ‘Kosui’ fruits were stored under a continuous flow of 0%, 1%, 3%, 5% and 10% O₂ (balance N₂) or air for 7 d at 20°C to study the effects of low O₂ on their physiological responses and quality attributes. Low O₂ treatments did not significantly influence changes in skin colour and soluble solids content. However, weak off-flavours were detected in the fruits stored at 0% O₂ on day 3, and the intensity of these off-flavours increased as storage progressed. The concentrations of acetaldehyde in fruit increased throughout the storage period. The ethanol concentration was greatly increased in fruits stored at 0% O₂. Moreover, ethanol concentrations were much higher than those of acetaldehyde and remained very low during storage in air, but their concentration were just slightly increased in fruits exposed to 1%, 3%, 5% and 10% O₂. Pyruvate decarboxylase activity was greatly increased in fruits exposed to 1% and 3% O₂, while its activity in fruits exposed to 5% and 10% O₂ were only slightly higher than that of the control and at 0% O₂ at the same level as the control. Alcohol dehydrogenase (ADH) activity greatly increased in fruit exposed to 0%, 1%, 3% and 5% O₂, while at 10% O₂, ADH was only slightly higher than the control. Changes in ADH isozymes correlated well with changes in ADH activity. The homogenate pH of fruits exposed to 1%, 3%, 5% and 10% O₂ and air remained constant, while in fruit stored at 0% O₂ their pH increased. The potential for using low O₂ atmospheres to help in maintaining the quality of Japanese pear ‘Kosui’ is discussed.     

A Comparison Investigation on Antioxidant Activities,Physicochemical Properties and Phytochemical Contents of Kiwifruit Genotypes and Cultivars

The present work was conducted to find the physicochemical properties, chemical components and antioxidant capacity of kiwifruit hydroalcoholic extracts (B-31, HO-1-14, J-242, Bruno, Greenlight, Hayward, Monty, Topstar) grown Yalova, Turkey. Phytochemical tests were performed to determine total phenolic, flavonoid and ascorbic acid. Moreover, the kiwifruit extracts were subjected to evaluate their antioxidant potential using different in vitro assays such as total antioxidant, inhibition of lipid peroxidation, reducing power, metal chelating, free radical, H₂O₂ and superoxide anion scavenging activities at 50–500 μg mL^?1, and also found EC₅₀ and IC₅₀ values. The soluble solid content (SSC), titratable acidity (TA) and pH were analyzed in all the genotypes and cultivars. The highest total phenolic, flavonoid and ascorbic acid content were found in J-242 (89.53 mg GAE/100 g), J-242 (109.13 mg QE/100 g) and HO-1-14 (64.15 mg/100 g), respectively. The linoleic, palmitic, stearic and oleic acid methyl esters were detected in all kiwifruit extracts by GC/MS. Significant differences were found between genotypes and cultivars in the antioxidant tests. The extracts showed high inhibition of lipid peroxidation and compared to standards, significantly (p < 0.05). The GC/MS analyses confirmed quantitative variability in the antioxidant profiles. The SSC, TA and pH of kiwifruit genotypes and cultivars showed a moderate level. The key parameters for the most active kiwifruit included the following: total antioxidant activity for B-31, H₂O₂ scavenging activity for J-242 and metal chelating activity for Topstar. In conclusion, this study exhibited the important role played by the genotypes and cultivars background on the chemical content and antioxidant profiles.     

Effects of CPPU on fruit set and fruit growth in Japanese persimmon

The effects of hand-pollination and spraying with N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) on fruit set and fruit growth of ‘Matsumoto-Wase-Fuyu’, which is a member of the pollination-constant, non-astringent group of persimmons (PCNA) were investigated. Staminate flowers of pollinizers in the orchard were eliminated before anthesis. Hand-pollination was carried out at full bloom (FB). Without prior hand-pollination, CPPU at 5 or 10 mg 1⁻¹ was sprayed 11 days after FB. Hand-pollination and spraying with CPPU increased fruit set before thinning of fruits by hand. The number of fruits after thinning did not differ among treatments. The yield of marketable fruits after hand-pollination was similar to that after treatment at 5 mg 1⁻¹, but was higher than that for untreated trees. Formation of a sunken fruit apex, which was observed in about 30% of fruits from untreated trees, was suppressed by application of CPPU. CPPU also delayed coloration of fruit. There were no differences among treatments in firmness or soluble solids concentrations of marketable fruits.     

Effects of cultivar and rootstock on the antioxidant content and physical characters of clingstone peaches

A study was conducted to investigate the variability in the fruit antioxidant content and physical characters of six clingstone cultivars and three breeding selections of peach grafted on three rootstocks. The parameters measured were fruit weight, fruit and stone dimensions, flesh color using CIELAB color variables, total antioxidant activity using the radical DPPH, total phenolics, ascorbic acid, soluble solids and total acid content. Fruit from cultivar PI-E45 had the highest total antioxidant activity (10.7 mg g⁻¹ DW) and total phenolic (6.9 mg g⁻¹ DW) content, which were up to 6.3- and 5.3-fold greater, respectively, compared with the rest studied cultivars. The highest ascorbic acid content was found in Fortuna (7.3 mg 100 g⁻¹ FW) and was up to 1.4-fold greater compared with the rest studied cultivars. A high correlation between AEAC and the phenolic content was found, but not between AEAC and the ascorbic acid content. The largest fruit was harvested in cultivar Andross followed with a descending order by PI-E45, PI-IB42, PI-A37 (seedlings of Andross), Fortuna and Loadel ? Everts and Catherina ? Romea. Changes in the fruit weight were usually according to changes in stone width. The fruit and stone shape differed among the cultivars but not among the rootstocks studied. Effects of rootstock on the fruit antioxidant contents were not pronounced. Nevertheless rootstocks altered the fruit weight since in all cultivars, apart from Romea and Catherina, when grafted on GF 677 produced the largest fruit (mean 186 g) followed by PR204 (mean 176 g) and even smaller by KID1 (mean 161 g). Results from correlation analyses showed that flesh brightness (measured in frozen fruit) may suggest for more nutritional flesh and small sized fruit may contain a redder and less bright colored flesh.     

完全雄性柿种质‘雄株8号’作为中国甜柿育种亲本的可能性研究

‘雄株8号’是中国中部大别山区分布的完全雄性柿种质,可能源自中国原产完全甜柿(中国甜柿)的杂交后代或是其自然变异,其作为完全甜柿专用授粉品种的可能性已有研究报道,但其作为完全甜柿育种亲本的应用潜力尚不明确。以‘华柿1号’(不完全涩柿)ב雄株8号’的杂交后代单株为试材,以常见中国甜柿、日本甜柿和非完全甜柿为对照,对其果实进行可溶性和不溶性单宁含量、单宁细胞大小等指标测定,确认杂交后代单株H8-2为具中国甜柿自然脱涩特点的完全甜柿类型。现有完全甜柿自然脱涩性状遗传特点的研究结果认为,只有日本甜柿相互杂交,或者是亲本之一为中国甜柿时,F_1才可能出现完全甜柿单株。该研究结果首次证明中国原产完全雄性柿种质‘雄株8号’带有控制自然脱涩性状的显性基因,因此其在完全甜柿遗传改良中具有作为育种亲本的应用潜力。     

Influence of a pre-harvest reflective orchard mulching film on lipid peroxidation and anti-oxidant activity in apple fruit during post-harvest storage

Summary

Studies have shown that applying a reflective film to the floor of an orchard enhances fruit colouration. Here we assessed whether this practice also prolonged the post-harvest storage life of apple (Malus domestica Borkh cv. Fuji and Malus prunifolia [Willd.]) fruit. Strips of reflective mulching film (RMF) were placed beneath the apple trees and RMF-treated fruit were compared with those from untreated control (CK) trees. Enzymes involved in reducing lipid peroxidation such as superoxide dismutase (SOD) and catalase (CAT) are associated with delaying fruit senescence. Their activities, as well as malondialdehyde (MDA) concentrations, were quantified as indicators of physiological changes related to lipid peroxidation and membrane damage in the peel and flesh of RMF-treated or control apple fruit during 50 d of post-harvest storage at 4ºC. SOD activities increased in the peel and flesh from RMF-treated fruit during the first 40 d post-harvest, but declined significantly during the final 10 d of storage. RMF treatment resulted in increases in CAT activities of 5 – 14% and 16 – 29% in the peel and flesh of RMF-treated apples, respectively, compared with untreated CK fruit. Conversely, MDA concentrations were 7 – 23% and 14 – 30% lower in the peel and flesh, respectively, of RMF-treated fruit than in CK fruit over the 50 d storage period. Similarly, RMF treatment resulted in reductions of 7 – 20% and 3 – 10% in saturated fatty acid (SFA) concentrations in the peel and flesh, respectively, compared to CK fruit, while the corresponding polyunsaturated fatty acid (PUFA) concentrations increased by 2 – 10% and 3 – 7%. In conclusion, the use of RMF in apple orchards appears to be an effective technique to delay post-harvest senescence in apple fruit.     

柿树乙醇脱氢酶活性与可溶性单宁含量的关系

研究了4种不同脱涩类型柿(Diospyros kaki Thunb)果实和叶片中的可溶性单宁含量、乙醇脱氢酶（alcohol dehydrogenase, ADH）活性和ADH最适反应温度,以了解ADH在脱涩过程中的作用。结果表明：不完全甜柿和完全甜柿果实发育前期,可溶性单宁含量逐渐降低,ADH活性逐渐增高,到果实基本完成脱涩后,ADH活性又开始降低,在不完全甜柿中变化较大;涩柿和不完全涩柿在果实近熟期,可溶性单宁含量有所下降,但不能完成脱涩,且ADH活性较低。叶片发育过程中,可溶性单宁含量的变化与ADH没有相关性。乙醇脱氢酶的最适反应温度在25℃左右。ADH与柿果实脱涩有一定关系。     

Effect of hail nets on the microclimate,irrigation requirements,tree growth,and fruit yield of peach orchards in Catalonia (Spain)

Summary

Hail nets protect orchards from storm damage, but also offer potential water savings for fruit trees grown in arid areas. We investigated the effects of black nets on water use, growth, yield, and fruit quality in peach trees growing in Catalonia, Spain, over 2 years (2006 and 2007). Water savings were quantified by irrigating the netted trees to a similar midday stem water potential (Ψ_stem) as the control trees. This method was only partially successful in 2006, with the netted trees being over-watered early in the season (i.e., higher Ψ_stem than the controls), and under-watered (i.e., lower Ψ_stem than the controls) later in the season. A combination of water stress and a hail net resulted in lower yields because of a smaller fruit size. Skin colour was more enhanced in control fruit. In 2007, Ψ_stem values were similar between treatments. Any difference in tree performance was therefore due to the hail net per se. Fruit size was similar between treatments, and the lower yields of netted trees were due to decreased fruit number. There were no treatment differences in fruit skin colour or flesh firmness. Soluble solids concentrations were higher in nonnetted fruit. In both years, water savings amounted to approx. 25%, if irrigation replaced the potential evapotranspiration that was measured. Hail nets are therefore recommended for their effects on water saving in arid areas, despite lower fruit yields.     

ABA、GA3 处理对冬枣采后果肉活性氧代谢的影响

 研究了100 mg·L ^{- 1}脱落酸(ABA) 和100μg·L ^{- 1}赤霉素(GA₃ ) 处理对冬枣冷藏期间果肉超氧阴离子自由基生成速率, 丙二醛、过氧化氢含量及相关酶活性变化的影响。结果表明: 低温( 0 ±2) ℃贮藏条件下, ABA处理促进了冬枣果肉丙二醛和过氧化氢的积累, 增大了超氧阴离子生成速率, 促进了过氧化氢酶(CAT) 和过氧化物酶( POD) 活性高峰提前出现, 多酚氧化酶( PPO) 活性的峰高增加,抗坏血酸氧化酶(AAO) 活性上升和酚类物质的快速下降, 说明果实后熟衰老被ABA处理提前, 而GA₃具有延缓作用, ABA和GA₃处理对活性氧代谢具有拮抗作用。