Addition of salicylic acid to nutrient solution combined with postharvest treatments (hot water,salicylic acid,and calcium dipping) improved postharvest fruit quality of strawberry

This experiment was conducted to study the effect of salicylic acid addition to nutrient solution and different postharvest treatments on fruit quality of strawberry cv. Camarosa after 7 days at 2 °C. Plants were irrigated with two complete nutrient solutions, with salicylic acid (0.03 mM) or without salicylic acid as the control. Fruits were then treated with eight different postharvest treatments (25 °C water, 45 °C water, 25 °C or 45 °C water containing CaCl₂ (1%), 25 °C or 45 °C water containing salicylic acid (2 mM) and 25 °C or 45 °C water containing both CaCl₂ (1%) and salicylic acid (2 mM)). Fruits which received SA in their nutrient solution had less weight loss and decay and higher firmness. All of the postharvest treatments improved fruit quality characteristics. Fruits dipped in salicylic acid solution had less weight loss, decay and a* (redness) and higher firmness and hue angle than control. Heat treated fruits had less decay and a* and higher hue angle than control. Fruits dipped in CaCl₂ solution had less weight loss, decay and a* and higher firmness than control. Combination of the three postharvest treatments improved firmness, decay, weight loss and vitamin C.     

Effect of postharvest application of calcium on ripening rates of pears and bananas

Dipping unripe pears (cv Williams Bon Chretien) in a solution of calcium chloride under reduced pressure (125-375 mm Hg) and subsequent storage at 20°C delayed ripening by up to 40% of the time taken for control fruit to ripen. The Ca-treated fruit ripened normally and a taste panel found that it was of good eating quality. However, dipping unripe bananas (cv Cavendish) in CaCl₂ solution, whether under ambient or reduced pressure, accelerated ripening.     

Copper distribution and ionic form effects for postharvest treatments of cut Acacia holosericea stems

A short postharvest life is the major constraint associated with cut Acacia flowers and foliage. Treatment with CuSO₄ (Cu²⁺) has previously been shown to improve the longevity of cut Acacia holosericea stems. Towards refining the treatments, a range of Cu²⁺ and Cu⁺ salts were assessed for relative efficacy in improving vase life and water relations of A. holosericea. Five hour pulses with the Cu²⁺ salts CuSO₄, CuCl₂, (CH₃COO)₂Cu and Cu(NO₃)₂ at 2.2 mM gave equally longer vase lives by ∼2.5-fold over deionised water (DIW) and standard tap water (STW) controls. The same Cu²⁺ salts at 0.5 mM in the vase solution also gave significantly (P < 0.05) improved vase life, relative fresh weight and water uptake compared to the DIW control. For Cu²⁺ versus Cu⁺, optimum concentrations with Cu²⁺ could not be directly compared due to the low solubility of the Cu⁺ salt CuCl. However, Cu⁺ from CuCl at 0.415 mM also had positive effects on vase life compared to the DIW control. Thus, both Cu²⁺ and Cu⁺ treatments can enhance vase life parameters for cut A. holosericea foliage. The benefits were irrespective of the counter ion and, thus, Cu²⁺ and Cu⁺per se were responsible. The most effective Cu²⁺ pulse treatment decreased stomatal conductance of phyllodes initially, but did not cause sustained stomatal closure. Cu accumulated to greater levels in basal stem and phyllode tissues than in upper stem and phyllode tissues of cut A. holosericea stems. Possible mechanisms of Cu²⁺/Cu⁺ action are discussed.     

采后1-MCP和热处理对红富士苹果生理变化和贮藏品质的影响

采用1-MCP(浓度为1μL/L,18h)、热空气(HA)38℃-96h及2者结合对富士苹果进行处理,处理后的果实置于(0±0.5)℃条件冷藏4个月,然后置于20℃条件下7d(模拟货架期)。试验发现在整个贮藏过程中所有处理组均能抑制果实的乙烯释放速率和呼吸强度,减缓果实硬度的降低。热处理组对固酸比的上升有显著作用,保持了较高的非水溶性果胶含量和较低的水溶性果胶含量。热处理在贮藏过程中对于果实硬度的保持与对照组相比起到一定的作用,但加速了果皮中叶绿素含量的降解。1-MCP处理组能够较好地抑制果实果皮的褪绿,保持果皮中较高的叶绿素含量,初期抑制细胞膜透性的上升,延缓果实的后熟衰老。结合处理组较好地保持果实膜的完整性,减缓了由热处理所引起的果皮叶绿素的降解,并保持较高的含酸量,保持了较好的风味品质。     

不同热水处理对杧果主要采后病害控制及贮藏期的影响

以海南3个主栽杧果品种,5种类型果实为试材,研究了3种不同的热水处理方式对主要采后病害的控制效果及其对果皮伤害和贮藏期的影响。结果表明,51℃、15min热水处理对供试果实炭疽病和蒂腐病2种病害的控制效果最好;供试果实对热的敏感性存在差异;热水处理加速果实的后熟速度,但适宜的热水处理可大大提高好果率,且病害发生严重时,因能有效控制病害发生从而延长贮藏时间。综合分析后推荐小贵妃、大贵妃、大台农、小金煌使用51℃、15min热水处理为最适宜的热处理方式。小台农使用47℃、20min热水处理作为最适宜热处理方式。     

Gibberellic acid soak treatments for fully-cooled tulips

In attempts to reduce the glasshouse period of fully-cooled 5°C-forced tulips, ‘Apeldoorn’ bulbs were soaked before planting in aerated and non-aerated gibberellic acid (GA₃) solutions for 2–48 h. A 48-h treatment with 250–500 mg l^?1 GA₃ was the most effective, giving a glasshouse period 7–11 days shorter than for untreated bulbs. Soaks for 24 and 48 h caused root emergence, and 48-h soaks caused perianth segment splitting in one experiment. Aerated or non-aerated GA₃ solutions gave similar results. Soaking in water alone gave a smaller increase in earliness. In general, a shortened glasshouse period was associated with shorter whole stem and last internode lengths. In GA₃ treatments, flower losses were lower than for distilled water treated and untreated bulbs. A practical treatment would be a non-aerated soak for 24 h with between 250 and 500 mg l^?1 GA₃.     

Shelf-life and quality of ber (Ziziphus mauritiana Lamk) fruits after postharvest water dipping treatments and storage

Summary

An experiment was conducted to study the effect of postharvest water dipping treatments and storage conditions on shelf life and quality of ber (Ziziphus mauritianaLamk). Fresh fruits of ber ‘Umran ’ were dipped in either cold (128C) or hot (50?C) water for 5 min and packed under different storage containers i.e. corrugated fibre board boxes, sealed polythene bags and perforated polythene bags. Control fruits were packed without dipping treatment. Result showed that postharvest water dipping at 508C for 5 min significantly increased the shelf life and maintained the quality of ber fruits, particularly late in the storage period. Fruits packed in sealed polythene bags significantly lowered the loss in fruit weight, spoilage and ripening with consequent increase in acidity and organoleptic score. Interactive results showed that hot-water treated fruits stored in modified atmospheric bags (sealed polythene bags) were qualitatively better than control fruits in terms of colour, taste and appearance. The organoleptic score reveals the acceptability of these fruits even after day 8 of storage. The control fruits were not found acceptable after day 4 of storage. It is suggested that postharvest fruit dipping in hot water (508C) forfive minutes followed by packaging in sealed polythene bags can enhance the shelf life and quality of ber fruits.     

乙酰水杨酸采前处理诱导哈密瓜果实的采后抗病性

【目的】探究果实发育期喷洒乙酰水杨酸(ASA)对哈密瓜果实采后抗病性的诱导效果以及对苯丙烷代谢和抗氧化酶活性的影响。【方法】以‘西洲蜜17号’哈密瓜为试材,分别在果实幼果期(花后14 d)、膨大期(花后21 d)、网纹形成期(花后28 d)和成熟期(采前2 d)4个时期采用1.0 mmol·L-1ASA进行喷洒,并对采后果实损伤接种粉红单端孢(Trichothecium roseum),观察处理对病斑直径及常温贮藏期间自然发病率的影响,测定果实采收及贮藏期间苯丙烷代谢关键酶活性和代谢产物含量,以及过氧化物酶和多酚氧化酶的活性。【结果】采前处理有效抑制了采后粉红单端孢损伤接种果实的病斑直径扩展,显著降低了果实常温贮藏期间的自然发病率,贮藏28 d时处理果实的自然发病率仅为对照的一半。处理显著提高了果实采收时肉桂酸-4-羟化酶的活性,以及类黄酮和木质素的含量。处理果实贮藏期间的苯丙氨酸解氨酶、肉桂酸-4-羟化酶和4-香豆酰辅酶A连接酶活性,以及总酚、类黄酮和木质素含量显著高于对照。此外,处理还显著诱导了果实采收时的过氧化物酶活性,提高了果实贮藏期间的过氧化物酶和多酚氧化酶活性。【结论】果实发育期采用ASA多次喷洒可有效诱导采后哈密瓜的抗病性,该诱抗作用与处理激活果实的苯丙烷代谢途径、增强过氧化物酶和多酚氧化酶活性密切相关。     

Responses of day-neutral,June-bearing and everbearing strawberry cultiv ars to gibberellic acid and phthalimide treatments

Field grown day-neutral, June-bearing and everbearing strawberry cultivars responded similarly to GA₃ in most cases. GA₃ stimulated daughter-plant production in ‘Hecker’ (DN) and suppressed it in ‘Guardian’ (June). Fifty mg l^?1 GA₃ increased initial runner production of all cultivars, while both 50 and 100 mg l^?1 GA₃ increased fruit yield the year following treatment. In greenhouse studies, GA₃ initially increased leaf number, petiole length and runner production, but the effects diminished with time. Phthalimide at 1000 mg l^?1 was most effective in increasing leaf number.     

Effect of pre- and postharvest salicylic acid treatment on physio-chemical attributes in relation to the vase life of cut rose flowers

With the aim of extending the vase life of cut rose flowers, we investigated whether the application of salicylic acid (SA), pre- and postharvest, could improve this. For this purpose, two individual trials were conducted, using a completely randomised design, with three replications. In the first trial, aqueous solutions of 0, 0.5, 1.0 and 1.5 mM SA were sprayed on roses grown in a controlled greenhouse once the flower buds had appeared, and the second stage was performed two weeks before harvest. The preharvest SA application at 1.5 mM concentration prolonged the vase life of cut roses by improving membrane stability, and decreasing the lipid peroxidation properties. In the second trial, continuous exposure to (0, 0.5, 1.0 and 1.5 mM), and pulses of (0, 5, 10 and 15 mM), SA significantly extended the vase life. Flowers treated with 1.5 (continuous exposure) and 15 mM (pulse) SA showed a significant decrease in weight loss, and antioxidant activity increased, compared to the control solution, but the flowers in the control solution indicated an increase in weight loss. The results show that pre- and postharvest SA application prolonged the vase life of cut roses through improving CAT and POD activity, and decreasing lipid peroxidation.     

Response of gladiolus (Gladiolus spp) plants after exposure corms to chitosan and hot water treatments

The state of Morelos, Mexico has gradually become an important producer of gladiolus. Some preconditioning treatments of corms are empirically done causing uneven emergence and low quality of flowers. In this investigation, before planting, gladiolus corms var. ‘Blanca Borrego’ were dipped in chitosan (chitosan reagent and commercial chitosan Biorend^®), in hot water at various temperatures and in treatments combined with Biorend^® at 1.5% and hot water. Results indicated that the most influenced variables were corm germination, number of flowers per spike, number of cormlets and vase life. Overall, the commercial product Biorend^® at 1.5% accelerated corm emergence in approximately 4 days, the number of flowers increased by 2–7 and the vase life extended for 3 days. The number of cormlets was also duplicated. Corms dipped in the commercial chitosan Biorend^® at 1.5% at different intervals of time were not greatly affected except for the emergence and number of cormlets. However, for this experiment there were significant effects on the number of leaves and flowers because of the interactions between chitosan and the immersion time. The temperature of 55 °C affected plant development because emergence was delayed by 6 days; and there were less number of leaves, flowers and cormlets. On the other hand, the incidence of Fusarium oxysporum in naturally infected corms was 0% at temperatures of 55 °C and 50 °C. Immersion times (0, 10, 15 and 20 min) in hot water at 50 °C did not show significant effects on plant development and vase life. Corms dipped in Biorend^® at 1.5% and hot water at 50 °C accelerated their emergence for about 1–7 days, the number of flowers increased by two, extended the storage life for 1–3 days and increased the number of cormlets. The integration of these two treatments -Biorend^® and hot water- might be a good option for increasing the gladiolus plant quality and vase life.     

Salicylic acid and jasmonic acid treatments for potentially extending the longevity of cut Acacia holosericea foliage

Acacia holosericea is a novel cut foliage line with a short vase life. Postharvest application of salicylic acid (SA) can extend the vase life of cut flower. SA is a host defence inducer, as is jasmonic acid (JA). SA and JA were compared as vase solution additives for A. holosericea. Three experiments were conducted that also compared these two chemicals with H⁺ and Cu²⁺ as known vase life extending additives. Vase solutions containing SA at 0.5, 1.5, and 2.5 mM gave ~1.3- to 1.5-fold vase life extensions as compared with the distilled water (DW; control). Provision of Cu²⁺ and JA at 0.5 mM in vase solutions also prolonged vase life by ~1.3-fold as compared with DW. The positive effect of SA tended to be greater than that of JA, but was inferior to that of Cu²⁺ at the same concentration. However, trend differences among these treatments were not statistically significant. Cut A. holosericea foliage stems treated with SA and JA exhibited higher relative fresh weight (RFW) and vase solution uptake rates as compared with DW. Overall, SA and JA evidently extended the vase life of cut A. holosericea foliage by inhibiting water loss and maintaining RFW during the vase period.     

Physicochemical analysis of mountain bananas from the French West Indies

The physicochemical characteristics of bananas grown at two different altitudes (L: 50 m and H: 300 m) in Martinique, French West Indies (FWI) were compared at four harvest stages with the aim of potentially promoting mountain bananas – which differ from current standard bananas – or export to the European market. At an equivalent harvest stage, highland (H) bananas were significantly thicker in diameter (grade), denser and firmer than lowland (L) bananas. After ripening, H bananas were significantly firmer and their peel was harder as compared to L bananas. Their dry matter and dry soluble extract contents and citrate concentrations were significantly higher than noted in L bananas. P contents were significantly higher in L bananas whereas Zn contents were higher in H bananas. A principle component analysis differentiated H and L bananas on the basis of their physicochemical characteristics. It was found that the “altitude” factor had a more marked effect than the “harvest stage” factor on the physicochemical characteristics of ripe fruit.     

Use of nitric oxide to reduce postharvest water loss from horticultural produce

Summary

Eleven types of fruit and vegetables and five types of flowers were held in an atmosphere containing a range of concentrations of nitric oxide (NO) gas in nitrogen for 2 h then stored for 24 h in air at 20°C and 60% r.h. Each type of produce was weighed before treatment, and after 24 h, and the rate of water loss calculated. Treatment with NO was found to result in 20% less water loss than in produce stored in air.     

Low-oxygen treatment for inhibition of decay and ripening in organic bananas

Summary

Application of a low-O₂ atmosphere for several days prior to storing organic banana clusters was effective in preventing decay development on the crown cuts, and in delaying ripening. Preclimacteric banana clusters (Musa spp. AAA group cultivar Ziv) were treated with a low-oxygen atmosphere (2%) at 208C for 24, 48 and 72.h immediately after harvest. After removal from low-O₂ stress, the bananas were stored at 128C for 21.d, and were then treated with ethylene at 188C for 24.h and transferred to shelf life at 208C for an additional 4.d. The low-O₂ treatments were compared with the commercial treatment of dipping the crown cuts in 0.2% thiabendazole (TBZ). The low-O₂ stress for 48 or 72.h was effective in preventing decay after shelf life, but less so than the TBZ treatment. Low-O₂ for 24.h was not effective enough, and the 72.h treatment markedly impaired colour development after ripening with ethylene. The 48.h low-O₂ treatment which resulted in the best decay prevention also retarded ripening processes (colour, ®rmness, respiration and ethylene production) and reduced chilling injury symptoms, without impairing the taste. The level of reducing sugars in the 48.h-treated fruit was similar to that in the control fruit after ripening and shelf life. The endogenous levels of acetaldehyde (AA) and ethanol produced by the treated fruit were lower than those in the control fruit during shelf life. It seems that there is a high potential for this physical treatment of low-O₂ stress to replace chemical treatments, as means of maintaining the quality of organic bananas.     

基于FCM测定的香蕉种质倍性分析

【目的】基于流式细胞术(FCM)分析结果,从细胞学层面上准确揭示不同基因组类型香蕉种质的倍性差异,为香蕉遗传多样性研究及选择育种提供基础支撑。【方法】以二倍体(AA)‘陵水野生蕉’(Musa AA acuminate‘Lingshui Yesheng Jiao’)为内参,利用FCM技术,对11份香蕉种质资源进行了倍性鉴定分析。【结果】依据(FCM)结果分析,参与分析样品的倍性可分为4大类:第I类有‘红河矮’蕉(M.AAA Cavendish‘Honghe Ai’)和‘陵水野生蕉’,属于2 N;第II类有‘始兴BB’(M.balbisiana‘Shixing BB’)、‘东莞中把大蕉’(M.ABB Cavendish‘Dongguan Zhongba Dajiao’)、‘Pisang Ceylan’和‘FHIA-18’4个种质,属于3 N;第III类有‘Cachaco’‘FHIA-17’‘FHIA-03’和‘TMB×5259-1’4个种质,均属于4 N;第IV类‘红香蕉’(‘Red banana’),在FCM分析中,此种质出现了2个峰值,第一个峰值为52.79,第二个峰值为103.24,测定时2个峰同时出现,且重复性好,可能是二倍体与四倍体混倍形成。【结论】较之传统方法,FCM准确揭示了DNA含量与倍性的关系,能更好地反映香蕉种质资源之间的遗传特征。     

Flowering and fruiting in ‘Patterson’ apricot (Prunus armeniaca) in response to postharvest application of gibberellic acid

In July or August of 1988 and 1989 which was approximately 2 or 6 weeks, respectively, after fruit harvest, cultivar ‘Patterson’ apricot (Prunus armeniaca) trees were sprayed with a single spray of either 10, 50 or 100 p.p.m. gibberellic acid (gibberellin A₃, GA). GA sprays of 100 p.p.m. applied in early July reduced flower number per centimeter of limb length in the year following treatment. Flower number per centimeter of limb circumference was reduced by sprays of 50 and 100 p.p.m. GA applied in July. Fruit set was not affected by GA sprays. The yield and fruit number of hand thinned trees was equivalent to that found on trees treated with 50 and 100 p.p.m. GA sprays in July. Individual fruit weight (size) was increased by GA sprays of 50 and 100 p.p.m. in July compared to hand thinned trees. Fruit maturity was advanced when yields were reduced by GA sprays. In July, GA sprays of 10 p.p.m. resulted in increased individual fruit weight without reduced total yields per tree compared to non-thinned control trees. Results showed that the use of GA sprays the year before flowering (July) decreased flower numbers, eliminating the need for chemical or hand fruit thinning of ‘Patterson’ apricot.     

利用拮抗酵母防治水果采后病害的研究进展

随着人们安全意识的提高,化学杀菌剂由于安全性差、且具致癌性等问题逐渐被淘汰,新型绿色、环保的生物防治逐渐成为当下研究的热点。拮抗酵母以其来源广泛、对营养条件要求低、生长迅速、安全性高等特点,在水果采后病害防治方面应用广泛。笔者在对拮抗酵母防治水果采后病害的来源途径、可能的拮抗机制以及增效途径进行综述的基础上,针对限制拮抗酵母商业化应用的原因进行了分析,即目前对拮抗酵母拮抗机制的研究还有待深入,同时工业上大规模生产的拮抗酵母制剂很难实现在实验室规模下发酵所具有的性质。通过组学等新的技术进一步揭示拮抗酵母防治采后病害的作用机制,进一步探讨拮抗酵母的分离干燥方式、佐剂以及剂型的选择,逐步完善适合拮抗酵母特性的商业化生产、销售方法和技术。     

部分香蕉品种SSR指纹图谱的构建

采用SSR标记技术构建香蕉品种的分子指纹图谱,为香蕉品种鉴定提供依据。以56份香蕉种质为材料,从199对引物中筛选出5对多态性及稳定性较高的SSR引物进行PCR扩增。5对引物在56个品种中扩增出的多态性带数在11～16个,平均为13.8条;引物的多态信息含量(PIC)在0.8490～0.9022,平均0.8727。依据香蕉SSR带型特征,对每个引物生成的不同带型直接编号,简化香蕉SSR带型记录方法,并利用每个品种的带型编号,建立其DNA分子指纹图谱,5对引物可将56份供试香蕉材料完全区分开。表明SSR标记技术可用以鉴定香蕉种质。     

Effect of hot acetic acid solutions on postharvest decay caused by Penicillium expansum on Red Delicious apples

The objective of this research was improvement of apple hot water treatment efficiency by using acetic acid. The apples (cultivar Red Delicious) were treated using hot acetic acid solutions (1, 2 and 3%) at 50 °C for 1, 2 and 3 min. The results of in vitro study showed that treatment with acetic acid at 50 °C can significantly reduce the growth of Penicillium expansum spores. The treatment of apples with 50 °C acetic acid solutions, in particular 2% acetic acid solution for 3 min or 3% acetic acid solution for 2 min, had significant impacts in reducing the extent of decay of the fruit during the short time storage experiment, while this effect was not significant in the long-time storage.