胡萝卜种子萌发过程中激素的测定和分析
毕业论文关键词：胡萝卜；休眠萌发；赤霉素；生长素；脱落酸
Determination and Analysis of Plant Hormones during Carrot seedsDormancy and GerminationAbstract: In this experiment, we studied the effect of different concentrations of GA3 on the carrot seedgermination. We also studied the effects of plant endogenous hormones gibberellin(GA3 and GA4),auxin(IAA), abscisic acid (ABA) and the interaction between hormones on the dormancy and germinationof carrot seeds by using the non-model plant "Kurodagosun" carrot seeds as the research object. Thecontents of endogenous gibberellin, auxin and abscisic acid were measured at 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, 7 dand 8 d after seed germination. Dynamic changes of endogenous plant hormones were measured duringgerminating. The results indicated that the effect of different concentration of GA3 on the carrot seedgermination is remarkable and the GA3 of 200 mg/L was prefer for increasing the germination rate. Thecontent of endogenous ABA showed a decreasing trend, which reached the lowest value at the 8 d aftergermination. The content of endogenous IAA increased during the process of germination. The content ofendogenous GA3 fluctuated greatly. And the content of endogenous GA4 showed a bimodal change. Thecontent of plant endogenous hormones GA3, GA4, IAA and ABA changed during the process of carrot seedgermination. And IAA and GAS played a synergistic role in promoting seed germination. ABA played anantagonistic role with IAA and GAS, which inhibited seed germination and promoted seed dormancy.
Key words:Daucus carota; Dormancy and germination;Gibberellin; Auxin; Abscisic acid
目录
摘要.2
关键词.2
Abstract2
Keywords2
引言.2
1材料与方法.4
1.1试验材料.4
1.2试验方法.4
1.2.1胡萝卜种子的处理条件.4
1.2.1.1胡萝卜种子预处理.4
1.2.1.2种子播种方法.4
1.2.1.3种子培养.4
1.2.2激素含量的测定.5
2结果与分析.5
2.1不同浓度赤霉素溶液处理对胡萝卜种子萌发率的影响.5
2.2胡萝卜种子萌发过程中激素含量的变化.5
2.2.1胡萝卜种子休眠萌发过程中生长素的含量变化.5
2.2.2胡萝卜种子休眠萌发过程中赤霉素的含量变化.6
2.2.3胡萝卜种子休眠萌发过程中脱落酸的含量变化.7
2.2.4胡萝卜种子休眠萌发过程中ABA/GA、ABA/IAA、IAA/GA的变化.7
3讨论.8
致谢.10
参考文献.11
引言：胡萝卜（Daucus carota）是伞形科的蔬菜作物，二年生草本。胡萝卜的种子小，其外皮革质化且含挥发油，透水性差，发芽十分缓慢且不整齐，发芽率较低，一般只有 70%左右，给生产带来了不利的影响。前人对胡萝卜的贮藏[1]、栽培[2]、杂交新品种[3]以及营养功能[4]研究较多，而对胡萝卜种子萌发过程中生理生化机制的研究较少。‘黑田五寸’胡萝卜是从日本引进的，是目前国内胡萝卜的主要栽培种之一。生产实践表明，‘黑田五寸’胡萝卜亩产可达 4000 公斤，较普通品种增产 20%，可溶性固形物和胡萝卜素含量高，已经成为国内外菜用和加工用胡萝卜的主导品种。因此，国内每年对 ‘黑田五寸’ 胡萝卜种子的需求量巨大， 利用中国丰富的土地资源以及劳动力进行 ‘黑田五寸’胡萝卜种子的繁育，以代替进口种子，可以降低生产成本，促进农业快速发展。但是因为繁种者本身缺乏质量意识或没有掌握科学的繁种技术而给农户和加工企业造成经济损失，为生产和育种带来了极大的不便[5]。种子是种子植物特有的延存器官， 种子休眠与萌发是植物体重要的生命活动之一[6]。种子休眠与萌发是一个复杂的生理生化过程， 由内部因素和外界环境因素的共同调控[7]。种子休眠是指一个完整可育的种子在适宜的条件下仍不能够萌发的现象[8]。种子的休眠通常被分为原发性休眠和二次休眠[9]。新鲜收获的具有透水性的成熟种子具有原发性休眠，由种子在母本植物上成熟的过程中所积累的 ABA 引起。与原发性休眠相反，没有进行深度生理休眠的种子可以诱导二次休眠，并且与种子库每年休眠周期相关[10]。