Physiological study on the cellwall during maturation and ripening in pear fruit.

1.用3年的时间测定了“法兰西”梨果果肉中的聚脲和淀粉含量。在开花后107 ~ 139天，聚脲和淀粉浓度保持较高水平，随后迅速下降至165天左右（“La”France的商业采收期），但绝对水平随年份而变化。当基于DAFB的商业采收时，果实在随后成熟过程中的软化程度随采收年份而不同。从这些结果来看，110-120 DAFB下果肉中淀粉和脲醛的浓度和组成可以作为预测果实收获后软化的有用指标。本研究在107-177 DAFB和119 DAFB中观察到14-C光同化物在不溶性果肉固体中的掺入。结果表明，随着成熟，果肉中高聚物的合成逐渐减少。梨果肉中含有石细胞。用间苯三酚染色法观察到梨果实中多核细胞的分布。绝大多数石细胞在核心外被检测到。石细胞的主要成分是木脂素，它是所有维管植物中含量最丰富的天然芳香有机聚合物，由松柏基、对香豆基、新树醇等酚类物质组成，在不同植物种类中比例不同。对木质素含量的分析进行了硫酸提取法和羟胺法测定。为提取梨果肉中的酚类物质，对几种酸、碱和有机溶剂的浓度进行了测试，结果表明，乙酰溴、氯酸、硫酸和高氯酸是较有效的溶解酚类物质的试剂。在梨幼果中，乙酰溴、高氯酸和氢氧化钠可溶性酚类物质含量随着果实的生长而增加，但随着果实的生长而减少，而硫酸和氯酸可溶性酚类物质含量随着果实的生长而增加。结果表明，果肉细胞壁中的酚类物质在果实生长和成熟过程中可能发生变化，并且（或）果肉细胞壁中含有多种酚类化合物。少

1.Polyuronide and starch content in the flesh of 'La France' pear fruit were measured during 3 years. In all years, polyuronide and starch concentration was kept high during the period 107-139 days after full bloom (DAFB) and then decreased rapidly till about 165 DAFB (the commercial harvest date of 'La' France), though the absolute level was varying with rear. When fruit was harvested at the commercial harvest based on DAFB,softenibg during the subsequent ripening differed with harvest years. From these results, concentrations and compositions of starch and plyuronide in flesh at 110-120 DAFB could be an useful index for predicting softening of fruit after harvest.2.Incorporation of 14-C photoassimilates into insoluble solid of flesh was observed in 107 and 119 DAFB during the experimantal period in this sudy (107-177 DAFB). This results shows that vigorous sinthesis of polymers in flesh decreased in maturing period.3.Pear fruits include stone cells in the flesh. Distribution of stone … More cells in pear fruits was observed by staining with phloroglucinol reagent. Most of the stone cells was detected ouitside of the core.4.Major component of stone cell is liglin, which is the most abundant natural aromatic organic polymers found in all vascular plants, and composed of phenolic substances such as coniferyl, p-coumaryl and sinapyl alcohols in varying ratios in different plant species. For the analysis of lignin content sulfuric acid extraction and determination method with hydroxylamine were tested.5.For the extraction of phenolic substances in pear flesh, concentraion of several kinds of acids, alkalis and organic solvent were tested, and acetylbromide, chloric acid, sulfuric acid, and perchloric acid were comparetively effective reagents to dissolve phenolic substances.6.In young pear fruit, contents of acetyl bromide, perchloric acid and sodium hydroxide soluble phenolic substances were greater and those decreased with fruit growth, while sulfuric andChloric acid soluble ones were increased with fruit growth.7.Results obtained in this study indicates that phenolic substances in flesh cell wall may change during fruits growth and maturation, and/or several kind of phenolic compounds were includes in flesh cell wall. Less