有机溶剂浸种对乌桕种子萌发的影响毕业论文

 2021-04-23 10:04

摘 要

本研究以采自徐州新沂的乌桕种子为试验材料,采用甲醇、乙醇、丙酮、石油醚4种不同有机溶剂对种子进行不同时间的浸种处理。通过比较不同处理后种子的生活力和发芽率变化情况,以探究有机溶剂浸种对解除乌桕种子休眠的影响,探索解除种子休眠的最佳浸种溶剂、浸种时间,为今后该种子的播种育苗生产提供理论依据。研究结果表明:不同有机溶剂浸种处理后乌桕种子的生活力具有显著差异,其中甲醇、乙醇、丙酮浸种处理显著降低了乌桕种子的生活力,浸种18h后种子的生活力分别为0%、28.9%、0%;而石油醚处理对乌桕种子生活力的影响不大,石油醚浸种5d后种子的生活力仍有93.3%。不同有机溶剂浸种处理后乌桕种子发芽率之间的差异也是显著的,甲醇、乙醇、丙酮浸种显著降低了乌桕种子的发芽率,处理后种子发芽率基本为0%;而在石油醚的浸种处理中,浸种18h和24h的种子其发芽率较对照组有显著提高,均从对照组的75.3%提高到了86.0%;浸种3d和5d的种子其发芽率明显低于对照组,其他处理与对照差异不显著。然而石油醚浸种24h乌桕种子生活力(92.2%)较浸种18h的种子生活力(100%)显著降低。综上,在本研究中采用石油醚浸种18h是打破乌桕种子休眠、促进种子发芽的最佳方法。

关键词:乌桕;有机溶剂;内源抑制物;种子萌发;休眠

Effects of organic solvents on the germination of Sapium sebiferum seed

ABSTRACT

Experiments were carried out on Chinese tallow tree (Sapium sebiferum (Linn.)Roxb.) seeds from Xinyi in Jiangsu province. Four kinds of organic solvents, methanol, ethanol, acetone, and petroleum ether, were used to seed soaking in different periods of S. sebiferum seed. The seed vitality and germination rate of S. Sebiferum seeds under different treatments were compared, in order to explore the effect of organic solvent soaking on breaking dormancy of S. Sebiferum seeds, and provide theoretical basis for the planting seeding production and application of the seed in the future. The results showed that: the effects of different organic solvent soaking on the seed viability of S. Sebiferum seeds showed significant difference. The treatments of methanol, ethanol, and acetone soaking significantly reduced the seed viability of S. Sebiferum seeds, with seed viability soaking after 18h were 0%, 28.9%, 0%,respectively. However, petroleum ether treatment had little effect on the seed viability, and seed viability of petroleum ether treatment soaking after 5d was 93.3%. Different treatments of organic solvent soaking also showed significant differences on the germination rate of S. sebiferum seeds. The germination of S. sebiferum seeds were significantly reduced by the treatments of soaking seeds in methanol, ethanol and acetone, and the seed germination rate were all close to 0%. However, for the treatment of petroleum ether, seed germination rate soaking after 18h and 24h were significantly higher than the control, both increased from 75.3% to 86.0%, seed germination rate of the treatments soaking after 3d and 5d were significantly lower than the control, while other treatments had no significant difference compared with the control. Besides, the seed viability of petroleum ether treatment soaking after 24h (92.2%) was significantly lower than that of 18h (100%). In summary, the treatment of petroleum ether soaking after 18h was the best way to break the seed dormancy and improve the germination rate of S. sebiferum seeds.

Keywords: Sapium sebiferum; organic solvent; endogenous inhibitor; seed germination; seed dormancy

目 录

1 文献综述

1.1 选题依据

1.2 国内外同类研究概况

1.2.1 种子休眠的研究进展

1.2.2 有机溶剂浸种与解除休眠的研究进展

1.3 研究内容、目的及意义

2 材料与方法

2.1 试验材料

2.2 试验方法

2.2.1 有机溶剂浸种处理

2.2.2 种子生活力测定

2.2.3 低温层积处理

2.2.4 种子发芽率测定

2.3 数据分析

3 结果与分析

3.1 不同浸种处理对乌桕种子生活力的影响

3.2 有机溶剂浸种对乌桕种子发芽率的影响

4 讨论

4.1 化学药剂处理对种子活力的影响

4.2 有机溶剂浸种对种子萌发的影响

4.2.1 促进种子萌发的化学方法的研究

4.2.2 有机溶剂浸种促进种子萌发的可能原因

5 结论

致 谢

参考文献

1 文献综述

1.1 选题依据

乌桕(Sapium sebiferum (Linn) Roxb.)别名蜡子树、木油树,为大戟科落叶乔木。产于我国秦岭、淮河流域以南,主要栽培区在长江流域以南浙江、湖北、四川、贵州、安徽、云南、江西、福建等省,在我国分布范围甚广。乌桕是一种色叶树种,集观形、观叶、观果于一体,具有极高的观赏价值已成为长江流域主要的秋景树种[1]。乌桕种子黑色、圆球形,含油,是重要的工业木本油料树种;同时,乌桕种皮表面白色的蜡层可以榨取固体的油脂叫桕脂或皮油;黑色种皮内的种仁,可以榨取液体油叫桕油或梓油[2];除此之外,乌桕还有广泛的药用价值,是我国特有的重要经济树种。

生产上乌桕以播种繁殖为主,然而该种子具有明显的休眠特性,这给其播种繁殖带来了很多不便。以往有研究发现,乌桕种子休眠主要是由于种皮和胚乳中含有内源抑制物[3]。本研究旨在通过采用有机溶剂进行浸种处理,以探讨有机溶剂浸种对乌桕种子萌发的影响,并进一步探究有机溶剂浸种对其内源抑制物去除效果的差异,为该种子在生产中的广泛应用提供一定的实践基础。

1.2 国内外同类研究概况

1.2.1 种子休眠的研究进展

种子休眠是指具有生活力的种子,在适宜的环境条件下仍不能萌发的生理现象[4],是植物在长期的发育过程中获得的一种抵御不良环境的适应性,然而这种休眠却给农林业生产带来诸多不便,使生产不能顺利进行。因此,对种子休眠解除开展研究具有十分重要的意义。

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