Abstract Ethychlozate (ethyl 5-chloro-1H-3-indazolylacetate, Figaron) was applied to 12-year-old ‘Jiefangzhong’ (a high-acid cultivar) loquat (Eriobotrya japonica) trees at 0 (control), 75, 150 and 250 mg L−1 on March 19th, 90 days after flowering. To determine pulp titratable acidity (TA), organic acid concentration and acid-metabolizing enzyme activity, fruits were collected at 0, 13, 25, 42 and 49 days after treatments (DAT), when fruits were ripe. Malate was the major organic acid determining loquat pulp acidity. Ethychlozate was very effective in reducing pulp malate concentration, thus decreasing pulp acidity. The best result for reducing acidity (malate) was obtained when ethychlozate was applied at 250 mg L−1. The ethychlozate-treated pulp showed lower phosphoenolpyruvate carboxylase (PEPC) and NAD-malate dehydrogenase (NAD-MDH) activities through the experimental period, but higher or similar NADP-malic enzyme (NADP-ME) from 25 to 49 DAT compared to non-sprayed control. The reduction in malate concentration in the ethychlozate-treated pulp was probably caused by decreased malate biosynthesis and increased malate degradation.

中文翻译：

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乙基氯酸盐降低枇杷（Eriobotrya japonica）果实的酸度

摘要 在 0（对照）、75、150 和3 月 19 日，开花后 90 天，250 mg L−1。为了测定果肉可滴定酸度 (TA)、有机酸浓度和酸代谢酶活性，在处理后 0、13、25、42 和 49 天 (DAT) 果实成熟时收集果实。苹果酸是决定枇杷果肉酸度的主要有机酸。乙基氯酸盐在降低果肉苹果酸浓度方面非常有效，从而降低果肉酸度。当使用 250 mg L-1 的乙基氯酸盐时，降低酸度（苹果酸盐）的效果最好。在整个实验期间，乙基氯酸盐处理过的纸浆显示出较低的磷酸烯醇式丙酮酸羧化酶 (PEPC) 和 NAD-苹果酸脱氢酶 (NAD-MDH) 活性，但与非-喷洒控制。乙基氯酸盐处理过的纸浆中苹果酸浓度的降低可能是由于苹果酸生物合成减少和苹果酸降解增加所致。