To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conduct...To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conducted at 0,1,3,and 5 days before harvest.The appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of storage.The results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli color.Furthermore,during the growth stage,total sugar accumulation was higher in the 5-ARG group.In addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest broccoli.In conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of broccoli.Therefore,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.展开更多
利用CMA-MESO和SWC-WARMS高分辨率模式2023年5—9月小时降水预报产品,四川自动站小时降水资料及CLDAS(CMA Land Data Assimilation System)三源融合小时降水资料,采用“点对点”和“点对面”检验方法,对两家高分辨率模式小时降水产品在...利用CMA-MESO和SWC-WARMS高分辨率模式2023年5—9月小时降水预报产品,四川自动站小时降水资料及CLDAS(CMA Land Data Assimilation System)三源融合小时降水资料,采用“点对点”和“点对面”检验方法,对两家高分辨率模式小时降水产品在四川地区的预报性能进行评估。主要结论如下:①小时降水10 mm以下和50 mm以上的极端降水,CMA-MESO的预报参考性显著优于SWC-WARMS;小时降水10~30 mm,5—6月以SWC-WARMS表现更优,7—9月则以CMA-MESO表现更佳。②空间偏差特征分析表明,两家模式的小时降水平均绝对误差空间分布整体较为一致,在盆周山区、川西高原及凉山州北部误差较大,模式误差和实况降水强度、海拔高度呈一定正相关,且SWC-WARMS的空间误差更大。③时间偏差特征分析表明,CMA-MESO的短时强降水站点频次峰值时间偏差为1~2 h,而SWC-WARMS达3~4 h。④为优化TS评分,针对CMA-MESO和SWC-WARMS模式,在空间上,预报时可分别考虑邻域半径9 km和12 km内出现对应量级降水的可能性;在时间上,对于5~30 mm小时降水,预报时可考虑预报时刻前后1 h和2 h发生的可能性,其他量级可考虑前后1 h。展开更多
文摘To determine the effects of preharvest arginine spraying on the nutritional level of broccoli and the mechanism of action of arginine in improving the storage quality of broccoli,arginine spraying(5 mmol/L)was conducted at 0,1,3,and 5 days before harvest.The appearance,respiration rate,mass-loss rate,electrolyte leakage,glucosinolate,ascorbic acid,total phenol,total flavonoid,total sugar and sucrose contents,and sucrose phosphate synthase(SPS),invertase(INV),sucrose synthase synthesis(SSS)and cleavage(SSC)activities of broccoli samples were observed after 0,2,4,6,8,and 10 days of storage.The results showed that spraying arginine at 5 days preharvest(5-ARG)helped to inhibit broccoli respiration during storage,delay electrolyte leakage,and maintain broccoli color.Furthermore,during the growth stage,total sugar accumulation was higher in the 5-ARG group.In addition,during the storage period,sucrose synthesis was accelerated,while sucrose cleavage was inhibited,resulting in more sucrose retention in postharvest broccoli.In conclusion,5-ARG resulted in the accumulation of more nutrients during the growth process and effectively delayed the quality decline during storage,thereby prolonging the shelf life of broccoli.Therefore,this study provides a theoretical basis for improving postharvest storage characteristics of broccoli through preharvest treatments.
