库尔勒香梨采后果实不同部位的呼吸多途径差异研究

摘要

Respiration rates of multiple respiratory pathways of different parts from postharvest fruit of Korla fragrant pear (Pyrus sinkiangensis Yu)were measured,in an attempt to confirm the relationship be-tween fruit climacteric postharvest and the respiratory main paths to exploring the theoretical basis for reg-ulation on climacteric and senescence of fruit postharvest.Total respiration rate and the rates of pathways including EMP (Embden-Meyerhof-Parnas ),TCAC (Tricarboxyficacid cycle ), PPP (Phosphopentose pathway),CP (Cytochrome pathway)and AP (Alternative pathway)were measured by oxygen electrode, in which postharvest fruits of Korla fragrant pear were sampled and were sliced into pulps,cores and peels for the measurements every 20 days in 120 days storage at 5℃.Remarkable result showed that peel had the highest respiration rates in 3 fruit parts of Korla fragrant pear postharvest,respiration rates of peel inclu-ding total respiration and multiple respiratory pathways were 7.84 to 23.97 times higher in average than the respiration rates of pulp,and were 2.79 to 13.43 times higher in average than the respiration rates of core. Fruit postharvest climacteric of Korla fragrant pear is the accumulation effect of multiple pathways respira-tory peaks from peel.Pulp had the lowest respiration rates in 3 fruit parts and neither had no signs of sig-nificant changes nor any respiratory peaks postharvest.EMP was the same respiratory main path either in peel or in core,but the obvious respiratory main path could not be found in pulp.Moreover,peel is a suit-able target site of metabolic regulation on climacteric and senescence for fruit postharvest.%以库尔勒香梨(Pyrus sinkiangensis Yu)为材料，测定果实采后不同部位的多途径呼吸速率，分析部位间不同途径的呼吸强度差异，以确定果实采后呼吸跃变与各部位呼吸代谢路径的关系。采收生理成熟香梨果实贮藏于5℃、相对湿度为95%的环境中，每隔20 d选取样果，使用液相氧电极法测定果肉、果心和果皮的总呼吸、糖酵解途径、三羧酸循环途径、磷酸戊糖途径、细胞色素途径和交替途径的呼吸速率。结果表明，库尔勒香梨果实采后果皮的呼吸速率相对最高，总呼吸与多个途径的呼吸速率比果肉平均高7.84倍~23.97倍，比果心平均高2.79倍~13.43倍；果实采后呼吸跃变是果皮多个途径呼吸峰叠加的表现。果肉是果实采后呼吸速率最低的部位，各个途径的呼吸速率未见明显变化和峰值出现。果皮和果心的呼吸主路径为糖酵解，果肉未现明显的呼吸主路径。适宜将果皮作为库尔勒香梨果实采后跃变衰老代谢调控的靶位。