To investigate how benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) may affect disease resistance of peach fruit (Prunus persica L. cv. Jiubao), harvested fruit were treated with 200 mg/L BTH solution for 5 min immediately after harvest, incubated at 22 ?C and 85-95% RH for 60 h, and then inoculated with Penicillium expansum at a concentration of 1.2×104 conidia per mL. The lesion area and disease-incidence of the BTH-treated fruit were 64.1 and 49.5%, respectively, lower than that of the fruit without BTH-treatment on the 7th day after the inoculation. In the inoculated fruit, the BTH-treatment enhanced the activities of phenylalanine ammonialyase (PAL), polyphenoloxidase (PPO) and peroxidase (POD) as well as the levels of total phenolic compounds and hydrogen peroxide (H2O2), which are considered to play important roles in plant disease resistance. Superoxide dismutase (SOD) activity and ascorbic acid (Vc) level in the inoculated fruit were also enhanced by the BTH treatment during the middle and later periods of the inoculation. The results showed that BTH treatment could significantly enhance the disease resistance of peach fruit after harvest and suggest that postharvest treatment with BTH holds promise as a new technology, substituting for chemical fungicide control of postharvest diseases in fruit.

Among three Hami melon (Cucumis melo L. var. inodorus Jacq.) cultivars (Kalakusai, 8601 and New Queen), there were clear differences in sensitivity to chilling injury (CI) during storage at 22 and 1℃. After 10 weeks storage and 1 week shelf life at 1℃, CI was high in Kalakusai fruit. At 3℃, 8601 fruit developed CI after 7 weeks storage and 1 week shelf life. At 5℃, CI was observed in New Queen fruit after 3 weeks storage and 1 week shelf life. Storage for 10 weeks at 3℃, 7 weeks at 5℃, and 3 weeks at 7℃ resulted in the lowest incidence of decay and the highest percentage of marketable fruit for Kalakusai, 8601 and New Queen melons, respectively. Principal fungi isolated from decayed fruit were Fusarium spp., Alternaria spp., Rhizopus spp., Mucor mucedo and Trichothecium roseum. The fruit held at lower temperature had better appearance, less browning and were firmer.

Induced resistance was studied in muskmelons (cv. Yindi) inoculated Trichothecium roseurn with postharvest 1,2,3-benzothiadiazole-7-carbothioica cid S-methyl ester (ASM) (100 mg L-1) or harpin (50 mg L-1) treatment. Both ASM and harpin significantly reduced lesion diameter in inoculated fruit. Lesion diameter was limited in the treated and untreated halves of the same fruit, indicating that the local and systemic resistance was induced. Inhibiting efficacy of elicitors lasted 7 and 5 days in the treated and untreated halves. The resistance increased by the chemicals was associated with the activation of peroxidase (POD) and chitinase (CHT). The elicitors induced a significantly and progressively increasing activity of POD and CHT in the treated and untreated halves, and the activation lasted at least 5 days. The activities of POD isoenzymes increased in the treated fruit. However, no new enzyme band was found in the treated and untreated halves.

Postharvest application of harpin to induce resistance was studied in two cultivars of Hami melon (Cucumis melo L. var. inodorus Jacq.) inoculated with Trichothecium roseum. Harpin significantly reduced lesion diameter in inoculated fruit. A greater level of decay control was observed in long-term storage cultivars (cv. 8601). The treatment at 90 mg/L was the most effective concentration and higher concentrations over 90 mg/L failed to promote resistance and did not cause phytotoxicity to melons. Harpin did not demonstrate any fungicide effect in vitro, but suppressed lesion diameter in treated and untreated halves of the same fruit, suggesting induction of local and systemic resistance. Efficacy of suppression lasted 8 and 6 days for '8601' and 5 and 3 days for 'New Queen' cultivars in harpin-treated and untreated halves, respectively. The protection by harpin was associated with the activation of peroxidase (POD) and chitinase (CHT).

The effect of sodium silicate (Si) for control of decay was tested in Hami melons (Cucumis melo L. var. inodorus Jacq.). Si significantly inhibited mycelial growth of Alternaria alternata, Fusarium semitectum, and Trichothecium roseum in vitro. Si at 100 mM was more effective than Si at 25 or 50 mM at controlling the diseases caused by the three pathogens, whereas Si at 200 mM was phytotoxic. Si treatments applied at 100 mM pre-inoculation with T. roseum had lower decay incidence and severity than treatments applied post-inoculation. The protection of Si was correlated with the activation of two families of defense-related enzymes, peroxidase and chitinase. Accumulation of both enzymes was induced in fruit treated with Si and challenged by T. roseum 24 h later, and was sustained for at least 9 days in 'New Queen' and 10 days in '8601' at room temperature. It appeared that induced resistance was an important mechanism of disease control in Hami melons treated with Si.

Silicon oxide and sodium silicate were investigated as potential agents for the control of postharvest pink rot in Chinese cantaloupe (cultivar Yujingxing) caused by Trichothecium roseum. In vitro tests showed that sodium silicate, when added to potato dextrose agar, was effective in suppressing the radial growth of the pathogen on the medium, whereas silicon oxide was ineffective. The effectiveness of sodium silicate increased with concentration, and the growth of the fungus was completely inhibited at 100 mm. When melons were dipped in the solutions, both silicon oxide and sodium silicate significantly (P < 0.01) reduced the severity of pink rot of the cantaloupe with lesion diameters reduced by up to fivefold when compared with the controls. Scanning electron microscopy-energy dispersive X-ray analysis showed that silicon (Si)-treated melons had a smoother surface feature and higher Si levels in the epidermis, especially at the stomata and along the junction between the exocarp and mesocarp. Enhanced peroxidase and phenylalanine ammonia lyase activities were observed in sodium-silicate-treated melons but not in those treated with silicon oxide. The results indicate that different mechanisms might be involved in sodium silicate and silicon-oxide-initiated reduction of postharvest pink rot in Chinese cantaloupe.

研究了枯草芽孢杆菌B1（Bacillas subtilis）结合苯丙塞重氮(BTH)处理或它们单独使用对甜瓜采后主要病害的生物防治效果。结果表明：所有处理都降低了Alternaria alternata、Rhizopus stolonifer、Fusarium semitectum的发病率。对于Thrichothecium roseum，B1 结合BTH 和B1 单独处理明显降低了病斑直径；对于A.alternata，BTH 单独处理和结合使用的效果较好；对于R.stolonifer，B1 结合BTH 和B1 单独处理的效果较好；对F.semitectum， 结合使用的效果较好。研究结果还显示，B T H、B 1及结合处理均能诱导甜瓜的过氧化物酶(POD)活性和几丁质酶 （CHT）活性的升高，并且可以持续8d。

研究了采后苹果醛浸泡处理对梨果实损伤接种扩展青霉（Penicillium epansum）的抑制以及活性氧代谢和抗氧保护体系的影响。结果表明：离体条件下，50、100、200mmol/L苹果醛处理对P.expansum菌落的生长均有明显的抑制作用，抑苗牢达到59%-64%，但3个处理浓度之间无显著差异。同样，上述3个浓度处理也明显抑制了处理后果实损伤接种P.expansum的病斑直径扩展，表明苹果醛处理诱导了果实体内的抗病陛。苹果醛处理对果实抗病陛的诱导与其影响细胞膜脂过氧化和活性氧代谢有关，处理果实丙二醛(MDA)含量、过氧化氢(H2O2)、超氧阴离子(O2-)和羟基自由基(.OH)水平被明显抑制。同时，过氧化物酶(POD)和超氧化物歧化酶(SOD)活性被明显诱导，谷胱甘肽(GSH)含量也显著上升。P.expansum损伤接种可进一步提高处理果实的H2O2O-2和OH水平，增强SOD和POD活性，降低NDA含量。

黄河蜜甜瓜在从开花至成熟的整个生长发育过程中，均可受到链格孢（Altemaria altemata）和镰刀菌（Fusarium spp.）的侵染，并且随着果实体积的膨大，这2种病原菌的带菌率明显提高。在花期花瓣的潜伏侵染率最高，在发育期、网纹形成期潜伏侵染率明显升高，并且A.altemata的侵染率明显高于Fusarium spp.的侵染率，在成熟期Fusarium spp.的潜伏侵染率略有下降。

膨大期、采收期、采后100d的苹果梨果皮的乙醇（甲醇）—二氯甲烷粗提取液经TLC分离，以链格孢为指示菌进行 生物活性分析均有不同比移值的抑菌带出现，采用气-质联用法（GC/MS）对其成分进一步分析表明，三个时期抑菌带成分存在差异。其中棕榈酸甲酯、油酸甲酯、亚油酸甲酯、鱼鲨烯（三十碳六烯）在膨大期含量最高，随着成熟和衰老的进行，含量逐渐降低，至采后100d，其含量分别为膨大期的1.8%、7.3%、19%和26.6%。推测它们是生长期间苹果梨果皮中存在的主要抗菌物质。邻苯二甲酸酯类是采收期和采后100d果皮中含量相对较高的抗菌物质，其中采后100d检出了4 种邻苯二甲酸酯，相对含量高达60%。它们可能为采后果皮中主要的抗菌物质。