油松种子萌发初始阶段物质代谢的研究

Material metabolism of Pinus tabulaeformis seeds during initial germinating stage

将油松种子置于(25±1)℃培养箱中培养,通过分析种子含水量、呼吸速率和胚乳内含物的变化,探讨油松种子萌发初始阶段的代谢规律。结果表明:油松种子中含水量和呼吸速率在萌发初始阶段的变化趋势完全一致,呈"S"型曲线,并可分为3个阶段,即快速升高阶段、滞缓阶段和重新迅速升高阶段。胚乳中的内含物质在培养最初27h降解不明显。可溶性糖在培养45h后含量大幅度降低,并于培养63h降为最低值1.23%;淀粉含量经36～45h短暂回升后迅速降低,培养72h降为最低值17.98%;蛋白质和粗脂肪比淀粉及可溶性糖动员稍快,在培养27h后含量就大幅度下降,是油松种子首先利用的贮藏物质,蛋白质和粗脂肪分别于培养54和72h时降为最低值15.84mg/g和47.44%。油松种子萌发初始阶段胚乳贮藏物质的降解主要在置床27h后,但贮藏物质代谢的启动时间略有差异。胚乳内含物在降解的同时相互转化,是一个复杂的代谢过程。

Metabolic mechanism of Pinus tabulaeformis seeds was studied during its initial germinating stage.Seeds were cultivated at（25 ± 1）℃ and associated changes of moisture content,respiration rate and stored materials were measured.The results revealed that the changes of moisture content and respiration rate followed the same＂S＂trend,which can be characterized into the following three stages：rapid increasing stage,retardation stage and renewed rapid increasing stage.The endosperm did not show significant metabolism during the first 27 hours.The soluble sugar of the endosperm had a large decrease after seeds being incubated for 45 hours and reached the minimum level at 63 hours（1.23% ）.The starch transitorily increased from 36 to 45 hours and then decreased afterwards to the lowest level at 72 hours（17.98% ）.Protein and crude fat mobilized faster than starch and soluble sugar.They both decreased rapidly after 27 hours and reached the lowest level at 54 and 72 hours（15.84 mg/g and 47.44% ）,respectively.Majority of the endosperm storage was metabolized after seeds being cultivated for 27 hours,but the metabolism starting points of different substances were slightly different.The metabolism of endosperm is a complex process.