粗榧种子休眠特性及萌发生理研究

发布时间：2019-05-03 20:57

【摘要】：粗榧属于第三纪孑遗植物,是我国特有树种,且用途广泛。但粗榧种子存在深度休眠现象,在自然条件下,种子成熟落地后2-3年才能萌发。本研究以粗榧种子为研究材料,探究种子休眠原因,并用不同浓度赤霉素和低温层积相结合的方法打破种子休眠,研究种子萌发进程与贮藏物质含量、相关酶活性变化及内源激素变化之间的关系,揭示粗榧种子的萌发机理。主要研究结果如下:(1)粗榧种子生活力达到90%以上,发芽潜力较大,但在无菌条件下培养30d,仍无发芽现象,说明粗榧种子存在深度休眠。(2)粗榧种子种皮不存在吸水障碍,不是种子休眠的原因;粗榧种子种皮及胚乳中均含有萌发抑制物质,且一直强度为种皮胚乳,说明内源抑制物的存在是种子休眠的主要原因。(3)层积过程中淀粉、蛋白质、粗脂肪等贮藏物质含量逐渐下降,可溶性糖、游离氨基酸等含量持续上升,淀粉酶、脂肪酶活性升高,说明淀粉、蛋白质等贮藏物质在相关酶的作用下,降解为可溶性糖、游离氨基酸等可溶性小分子物质,为种子萌发提供物质与能量。(4)层积过程中,萌发抑制物质ABA含量持续下降,萌发促进物质GA、IAA含量呈上升趋势,ZR含量呈现先下降后上升的趋势,说明萌发抑制物质含量减少,促进物质含量增多是粗榧种子破除休眠,促进萌发的关键;GA/ABA、IAA/ABA及ZR/ABA均呈现增大趋势,说明种子休眠的破除还与激素之间的比值有很大关系,内源激素之间相互协调,共同作用于种子萌发过程中。(5)层积过程中四种不同处理的种子发芽率分别为12.7%、29.2%、21.7%和18.4%,说明层积处理能打破种子休眠,促进萌发;200mg·L-1 GA3与层积相结合的处理对种子萌发的促进效果最好,该方法可用于生产实践中。
[Abstract]:Torreya grandis belongs to Tertiary relict plants, is a endemic tree species in China, and widely used. However, there was deep dormancy in the seed of Torreya grandis. Under the natural conditions, the seed germinated 2 years after the seed matured to the ground. In this study, the seed dormancy of Torreya grandis was studied, and the seed dormancy was broken by the combination of gibberellic acid and low temperature stratification, and the germination process and the content of storage substances were studied, and the seed dormancy was broken by different concentration of gibberellin. The relationship between the changes of enzyme activity and endogenous hormones revealed the germination mechanism of Torreya grandis seeds. The main results are as follows: (1) the seed viability of Torreya grandis is more than 90%, and the germination potential is great, but under aseptic condition for 30 days, there is still no germination phenomenon. (2) there is no water absorption obstacle in seed coat of Torreya grandis, which is not the reason of seed dormancy; Both seed coat and endosperm of Torreya grandis contain germination inhibitor, and the endosperm intensity is the seed coat endosperm, which indicates that endogenous inhibitor is the main reason of seed dormancy. (3) starch and protein in the process of stratification. Crude fat and other storage substances gradually decreased, soluble sugar, free amino acids and other contents continued to increase, amylase, lipase activities increased, indicating that starch, protein and other storage substances in the role of related enzymes, degradation into soluble sugar, Soluble small molecular substances, such as free amino acids, provide material and energy for seed germination. (4) during the process of stratification, the content of ABA, the inhibitor of germination, continues to decrease, and the content of GA,IAA, which promotes germination, tends to increase. The content of ZR decreased first and then increased, indicating that it was the key to break dormancy and promote germination of Torreya grandis seed to decrease the content of inhibiting substance and promote the increase of substance content. Both GA/ABA,IAA/ABA and ZR/ABA showed an increasing trend, indicating that the breaking of seed dormancy was also related to the ratio of hormones, and endogenous hormones coordinated with each other. (5) the germination rates of the four different treatments were 12.7%, 29.2%, 21.7% and 18.4%, respectively, which indicated that the stratification treatment could break the dormancy of seeds and promote the germination of seeds, and the seed germination rate of the four different treatments was 12.7%, 29.2%, 21.7% and 18.4%, respectively. The combination of 200mg 路L-1 GA3 and stratification has the best effect on seed germination, and this method can be used in production practice.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S791

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