Improving disease resistance in peach fruit during storage using benzo-(1,2,3)-thiodiazole-7-carbothioic acid S-methyl ester (BTH)

Summary

The compound benzo-(1, 2, 3)-thiodiazole-7-carbothioic acid S-methyl ester (BTH) effectively induces a systemic acquired resistance (SAR) response in plants and increases plant resistance to disease. To learn how BTH may affect post-harvest quality and disease resistance in peach, (Prunus persica L. cv. ‘Jiubao’) peach fruit were treated with 200 mg l^–1 BTH for 5 min immediately after harvest, then incubated for 60 h at 20°C, 85–95% RH. Sixty h after treatment, fruit were inoculated with spore suspensions of Penicillium expansum at 1.2 10⁴ CFU ml^–1. The incidence of disease and lesion areas on peach fruit were significantly reduced by BTH-treatment (P < 0.05). In addition, chitinase and -1,3-glucanase activities in peach fruit were significantly enhanced by BTH-treatment (P < 0.05). Moreover, the total levels of phenolic compounds and chlorogenic acid, and the lignin content of BTH-treated fruit were significant higher than in control fruit (P < 0.05). The effects of BTH on fruit quality were also analysed. Soluble solids content, soluble pectin, titratable acidity and ascorbic acid levels in peach fruit were not significantly affected by treatment with BTH. Our results suggest that the application of BTH may control post-harvest diseases in peach fruit during commercial production.     

Benzothiadiazole- or methyl jasmonate-induced resistance to Colletotrichum musae in harvested banana fruit is related to elevated defense enzyme activities

Summary

The ability of benzothiadiazole (BTH) or methyl jasmonate (MeJA) to induce disease resistance in harvested banana fruits was investigated in relation to the activities of several defense-related enzymes. Harvested banana fruit were sprayed with BTH or MeJA solution before being stored at 22°C. Disease development and the activities of six defense-related enzymes were monitored during storage. Compared with untreated fruits, BTH or MeJA treatment significantly reduced the severity of disease in non-inoculated bananas, and lesion diameters and the incidence of disease in bananas inoculated with Colletotrichum musae. The activities of the defense-related enzymes peroxidase (POD), catalase (CAT), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), β1,3-glucanase, and chitinase were all enhanced in BTH- and in MeJA-treated banana fruit whether inoculated with the pathogen or not. The results suggest that post-harvest decay in bananas can be controlled by BTH or MeJA, and involves activation of the disease defense system. In non-inoculated bananas, MeJA and BTH had similar effects on the three defense enzymes (CAT, PPO and PAL), but different effects on the three PR proteins (POD, β1,3-glucanase and chitinase). In inoculated bananas, MeJA and BTH had similar effects on all six enzymes.     

BTH处理对不同生育期甜瓜抗白粉病的诱导效应

以幼苗期、伸蔓期和幼果期的黄河蜜甜瓜为试材,研究了苯并噻二唑(BTH)处理对3个生育期甜瓜植株抗白粉病的诱导效应。结果显示:0.25mmol·mL-1BTH对幼苗期和伸蔓期甜瓜植株的诱导效果显著高于幼果期甜瓜植株,而伸蔓期和幼苗期植株之间病情指数差异不显著;0.25mmol·mL-1BTH处理后,幼苗期甜瓜植株叶片中β-1,3-葡聚糖酶(GLU)活性在接种白粉菌后增幅最大,伸蔓期次之,幼果期最小;无论是诱导+接种的植株,还是只接种的植株,叶片中的苯丙氨酸解氨酶(PAL)活性高峰都随着苗龄增大呈现出不断推迟的现象。     

A single application of Milsana® followed by Bion® assists in the control of powdery mildew in cucumber and helps overcome yield losses

Summary

The efficacy of candidate activators of systemic acquired resistance (SAR), Bion^® (Syngenta, Basel, Switzerland), Rezist^® (Stoller Enterprises, Houston, Texas, USA), and Milsana^® (P. J. Margo Pvt. Ltd., Bangalore, India), was evaluated for the control of powdery mildew (Podosphaera xanthii) on cucumber and zucchini. Each candidate activator significantly reduced the incidence of disease on both crops in a glasshouse, where spore inoculum was applied to treated leaves. Both Bion^® and Rezist^® induced increased chitinase activity in plants, confirming their action as activators of SAR. However, Milsana^® did not have this effect, suggesting that its mode of action was as a direct inhibitor of infection by spores. In the field, two or three applications of Bion^®, at 14-day intervals, gave consistently better results in protecting cucumber plants from powdery mildew. Several applications of Milsana^® alone were less effective than a single application of Bion^® alone. However, several applications of Bion^® adversely affected plant growth, resulting in lower yields. The application of Milsana^® before or after Bion^® provided effective control of powdery mildew and minimised the adverse effects of Bion^® on yield. Application of all three candidate activators alone, on field-grown zucchini did not control powdery mildew, although a systemic increase in chitinase activity occurred in response to Bion^® or Rezist^®. A greater understanding of the mode of action of Milsana^®, and of the interaction between disease load and the timing of activator application(s) may improve the control of powdery mildew.     

诱抗剂处理对甜瓜叶部病害和果实品质的影响

以抗病品种银帝和感病品种卡拉克赛为材料,在露地条件下研究了几种植物提取液和苯并噻二唑(BTH)处理对甜瓜主要叶部病害及果实大小和品质的影响。结果表明,BTH、中草药提取液和侧柏提取液对甜瓜叶部各种主要病害的发生都有明显的抑制效果,尤其对白粉病的抑制效果最好,平均防效达75%。4种诱导剂中,BTH对各种病害的防效都较稳定,平均达51.44%,且在幼果期和伸蔓期+幼果期的预防效果均较植物提取液好。采前诱抗处理能明显提高两品种甜瓜果实品质及抗病品种(银帝)的产量,但对感病品种卡拉克赛产量影响不显著;初花期BTH处理可增加果肉厚度、提高可溶性固形物含量,并能改善果实经济性状。     

Effects of post-harvest calcium chloride or salicylic acid treatments on the shelf-life and quality of apricot fruit

Summary

The purpose of this work was to estimate the effects of post-harvest calcium chloride or salicylic acid treatments on the physicochemical characteristics and shelf-life of apricot (Prunus armeniaca L.) ‘Asgar-Abad’ fruit stored at 1ºC in a normal atmosphere for 21 d after harvest. Fruit were dipped in deionised water (control), or in 40, 60, or 80 mM CaCl₂, or in 1.0, 2.0, or 3.0 mM salicylic acid (SA) for 10 min.Total soluble solids (TSS) contents, titratable acidity (TA), ascorbic acid contents, total phenolics contents, and total anti-oxidant activity were determined 7, 14, or 21 d after each treatment. Fresh weight (FW) loss, titratable acidity, and TSS contents were improved by all treatments. Fruit treated with 3 mM SA exhibited the highest phenolics content during the storage period. At the end of the storage period, the highest values of TSS were observed in the 2.0 mM and 3.0 mM SA treatments. This experiment revealed that post-harvest treatment with SA or CaCl₂ prolonged the storage-life and preserved the valuable marketing characteristics of apricot fruit, presumably because of their inhibitory effects on fruit softening, ripening, and senescence. Over 21 d in cold storage, 2.0 mM SA was found to be the best treatment to maintain fruit quality in terms of FW loss, while 60 mM CaCl₂ was optimal for achieving high ascorbic acid concentrations and enhancing the anti-oxidant capacity of fruit.     

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.     

类球红细菌对草莓生长及抗病性的影响

为探究类球红细菌对草莓的抗病、促生作用效果,分别在草莓苗期、初花期、果实膨大期施用助友宝S O D微生物菌剂100倍液,研究其对草莓株高等生长指标、果实产量的影响及对草莓白粉病的防治效果.结果表明:助友宝S O D微生物菌剂可使株高提高2.3％,茎粗提高9％,展开叶片数提高20.7％,开花数量增加19％,草莓单果质量增...     

BTH和水杨酸(SA)对甜瓜抗白粉病的诱导作用

研究了BTH和水杨酸(SA)作为诱导剂在不同浓度,不同时期对甜瓜抗白粉病的诱导作用。采用盆栽甜瓜植株,喷施诱导剂,然后接种甜瓜白粉菌的方法测定这2种诱导剂对甜瓜的诱导效果。结果表明2种诱导剂均对甜瓜有明显的诱导作用。BTH最佳诱导浓度为50μg／mL,SA为25μg/mL,平均诱导效果分别为86,6％和83．7％。在最佳诱导浓度下,2种诱导剂诱抗的持效期至少可达17 d。在2—8叶期,BTH和SA处理均有良好的诱导效果,且差异不显著。诱导剂本身对甜瓜白粉病菌分生孢子萌发及菌丝生长无明显影响。     

BTH处理网纹甜瓜对两种真菌潜伏侵染率的影响

分别于网纹甜瓜开花前7 d、幼果期（花后14 d）、果实迅速膨大期（花后21 d）和网纹形成期（花后28 d）用100 mg·L^-1 BTH对植株进行1、2、3、4次喷洒,分析BTH处理后幼果期、膨大期、网纹形成期和成熟期果实内链格孢（Alternaria alternata）和镰刀菌（Fusarium sp.）潜伏侵染率的变化。结果表明：采前BTH处理可有效控制甜瓜果实内两种真菌的潜伏侵染。1、2、3、4次处理均降低了两种真菌的潜伏侵染率,2、3、4次处理的效果较好,在成熟期总潜伏侵染率均为对照的23.53 %。网纹形成期是两种真菌潜伏侵染的关键时期。采前BTH处理对潜伏于果实内的两种优势病原菌链格孢和镰刀菌的控制效果存在差异,且对果实顶部、中部的控制效果优于底部。     

中国南瓜新品种皖蜜品种比较试验初报

皖蜜为中国生态型南瓜杂交一代品种。植株生长势旺,易坐果,全生育期约105d,从雌花开放到果实成熟约28d。单果重4.0～5.0kg,果实美观,棒槌形,果面有蜡质光泽;果肉厚、橙红色,含糖量高,口感风味佳;嫩果黄绿色,成熟果深黄,嫩老果均可食用。667m2产量2500～3000kg。抗病毒病、白粉病。     

甜瓜不同生育期BTH处理对其主要叶部病害抗性的诱导作用

以甜瓜品种银帝和卡拉克赛为试材,在伸蔓期、初花期和幼果期进行苯并噻二唑（BTH）处理,研究BTH对甜瓜霜霉病、白粉病和炭疽病的防控效果。结果表明：与对照相比,BTH处理后显著降低了银帝和卡拉克赛的病株率和病情指数,各处理的防病效果品种间存在差异;对霜霉病,幼果期BTH处理效果较好,采前7 d时,伸蔓期+幼果期BTH处理诱导防病效果较好,两品种分别达到40.00 %和49.62 %;对白粉病,各处理对银帝的防病效果在采前7 d时高达75 %,银帝病株率和病情指数都低于卡拉克赛,且发病较卡拉克赛晚;幼果期BTH处理后显著降低了银帝和卡拉克赛发病初期炭疽病的病株率和病情指数,采前7 d时对银帝的诱导防病效果是幼果期BTH处理较好,为72.79 %,对卡拉克赛则以伸蔓期+幼果期BTH处理的诱导防病效果较好。     

南瓜新品种兴蔬红蜜的选育

兴蔬红蜜南瓜是由两个自交系M2和M3配制成的一代杂种,抗白粉病,生长势强,第1雌花节位22节左右,主侧蔓均可结瓜,果实长葫芦形,成熟果桔黄色带白条纹,果面有棱沟,商品瓜长44 cm左右,单瓜质量3.5～5.0 kg.果实可溶性固形物含量7.2%左右,口感粉、甜.老熟瓜开花后35 d采收,一般1 hm2产48 000 kg左右,适合华中、华南露地栽培.     

厚皮甜瓜新品种红星的选育

红星是以自交系0801为母本,以金20-1为父本配制而成的中早熟厚皮甜瓜一代杂种,全生育期75～90 d（天）,果实发育期33～35 d（天）,植株长势中等,抗逆性强,田间表现高抗霜霉病,中抗蔓枯病,抗白粉病。果实高圆形,果皮光滑、亮黄色;果肉红色,肉厚4.0～4.5 cm,肉质脆甜,可溶性固形物含量15.5 %以上,平均单果质量2.0 kg,保护地适宜栽培密度为2 000株·（667 m²）^-1,每667 m²产量4 000 kg左右。适宜在华北及条件适宜的保护地栽培。     

Slowing the deterioration of mango fruit during cold storage by pre-storage application of oxalic acid

Summary

The effects of pre-storage application of oxalic acid (OA) on the incidence of decay and ripening in mango fruit, and its physiological effects on the peel and flesh of mango were investigated after mango fruit (Mangifera indica L. cv. Zill) were dipped in 5 mM OA for 10 min at 25ºC then stored at 14º ± 1ºC for 5 weeks. In addition, spore germination and mycelium growth of Colletotrichum gloeosporioides Penz. on potato dextrose agar (PDA) media containing different concentrations of OA were measured. Application of OA decreased the incidence of decay and delayed the ripening process in mango fruit during cold storage. However, there was no reduction in fruit quality, as judged by the soluble solids content (SSC) and titratable acidity (TA) of fruit ripened at 25ºC for 3 d, following 3 weeks of cold storage. Oxalic acid-treatment resulted in decreased lipoxygenase (LOX) activity and increased superoxide dismutase (SOD) activity in the peel, and increased ascorbate peroxidase (APX) activity in both the peel and the flesh, coincident with a decrease in reactive oxygen species (ROS).At or above 5 mM, OA with unaltered (natural) pH or after neutralisation, also inhibited C. gloeosporioides development in vitro. It is suggested that the physiological effects of OA, in decreasing LOX activity and enhancing defense against oxidation damage, contributed to delaying the ripening process in mango fruit during cold storage. Thus, pre-storage application of OA could be a promising method to suppress post-harvest deterioration and extend the shelf-life of refrigerated mango fruit, possibly due to a combination of its physiological effect in delaying the ripening process, coupled with an inhibition of the development of pathogens such as C. gloeosporioides.     

早熟南瓜新品种兴蔬蜜宝的选育

兴蔬蜜宝是由自交系M2和15-3配制而成的南瓜一代杂种，抗白粉病，生长势中等，第1雌花节位为第11节 左右，主蔓结瓜为主，果实长葫芦形，成熟果橘黄色覆白条纹，果面有棱沟，商品瓜长34 cm左右,单果质量3.5 kg。可溶性固形物含量77.5 g·kg^-1，口感粉面、甜。开花后40 d（天）采收成熟瓜，每667 m²产量2 200 kg左 右，适于长江流域保护地栽培。已在湖南、四川推广种植500 hm²。     

The effects of glass cloche and coloured polyethylene tunnels on microclimate,growth, yield and disease severity of strawberry plants

Marked differences in the microclimate and the performance of strawberry plants were observed under glass cloches and clear polyethylene tunnels as compared with coloured polyethylene tunnels. Under glass and clear film the average air and soil temperatures were higher and fluctuated more, and the vapour pressure deficit was greater during the day, than under coloured film. The plants under glass and clear film made more vigorous early growth and cropped earlier than those under the other tunnels, but the heaviest yields were picked from plants under red and pink covers. Flowering and fruiting were delayed under green and blue covers by at least one month, and yields were comparatively small owing to poor pollination and fruit set.

Both strawberry mildew (Sphaerotheca macularis (Wallr. ex Fr.) Lind.) and Botrytis fruit rot were more severe on plants under the coloured films than under glass or clear film.     

Effects of post-harvest salicylic acid treatment on fruit quality and anti-oxidant metabolism in pineapple during cold storage

Summary

Pineapple (Ananas comosus L. ‘Comte de Paris’) fruit at commercial maturity (180 fruit per treatment, three replicates) were immersed in 0, 1.0, 3.0, or 5.0 mM salicylic acid (SA) for 15 min, then stored at 10ºC and 90% relative humidity (RH) for 20 d. After 20 d in cold storage, they were moved to 20ºC for 2 d to simulate shelf-life. Physiological and biochemical responses were studied. The results showed that the 3.0 or 5.0 mM SA treatments lowered the internal browning (IB) index, while the 5.0 mM SA treatment decreased the soluble solids content (SSC), titratable acidity (TA), and soluble sugar content, but increased ascorbic acid (AsA) levels at the end of shelf-life. Furthermore, during cold storage, all SA treatments significantly decreased the rate of tissue respiration in pineapple fruit. SA at 5.0 mM significantly decreased the activities of peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL), but increased the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) compared with the non-SA treated (untreated) controls. Overall, these results indicate that post-harvest treatment with 5.0 mM SA delayed the occurrence of IB in pineapple, extended its shelf-life, and maintained fruit quality during cold storage.     

优质厚、薄皮甜瓜中间型新品种开甜2号的选育

开甜2号是以自交系M90为父本、M89为母本组配的厚薄皮甜瓜早熟杂交一代品种。全生育期85d左右,果实发育期28d左右。优质、高产。田间表现抗枯萎病、霜霉病,兼抗白粉病。果实圆形,果皮果肉均为白色,肉厚3.8cm,中心可溶性固形物含量15%～18%。单果质量500g以上,667m2产量3500kg左右。全国大部分地区保护地、露地条件下均可栽培。     

Harvest parameters to improve the storability of high quality ‘Reinette du Canada’ apple

Summary

‘Reinette du Canada’ apple (Malus domestica Borkh.), which has been declared a Protected Designation of Origin (PDO) product throughout the European Community, is severely affected by bitter pit during storage, but increasing demand for organic produce requires chemical post-harvest treatments to be replaced with organic practices. The objective of this work was to determine the optimum stage of fruit maturity to improve the storability of high quality ‘Reinette du Canada’ apple during storage without applying post-harvest treatments. Seasonal conditions influenced fruit quality and the occurrence of storage disorders in ‘Reinette du Canada’. Harvest maturity also influenced the quality of ‘Reinette du Canada’ apple during storage, with later harvests reducing the development of bitter pit and increasing the soluble solids content:titratable acidity (SSC:TA) ratio. This study suggests that the SSC:TA ratio was a useful parameter for determining the optimum harvest maturity for high acidity, ‘Reinette du Canada’ apple. High quality fruit were obtained after long-term storage when the SSC:TA ratio exceeded 11.0, and fruit firmness at harvest exceeded 90 N. If these thresholds were not achieved, the quality of harvested ‘Reinette du Canada’ apples may not be sufficient to market fruit with the PDO designation. The results of our study also suggested that skin hue angle (hº) measurements may provide a quick and useful index that could replace fruit firmness measurements in the future.