摘要甘薯大田繁殖为茎蔓扦插繁殖,往往在干旱盐碱等逆境条件下会因为不能及时形成不定根而导致幼苗存活率降低。为研究影响甘薯不定根形成及发育的因素，本实验以徐薯28为实验材料，采用水培的方法，研究了胞外核苷这一重要胞外信号转导分子对甘薯幼苗不定根发生效率及根伸长的影响。结果表明0.1 mM的ATP处理组对不定根的伸长有明显的促进作用，但是对不定根发生效率并没有显著影响。当ATP浓度达到5 mM时，对根的长度便表现出显著的抑制作用，而且根部还受到了一定程度的伤害。整体来看ATP对甘薯苗生根效率有一定的抑制作用；ADP的几个实验组均表现出了根系伸长抑制性，1 mM和5 mM的处理组根系数目在前几日稍有增多，后几日显现出抑制性；100 μM的PPADS（嘌呤受体抑制剂）处理组对不定根伸长和发生都有显著的抑制作用，50 μM的PPADS处理组对不定根的伸长有一定的促进作用。以上实验结果说明胞外核苷信号参与了甘薯不定根的形成和根发育，但是具体机制仍有待进一步研究。71691

该论文有图6幅，照片18张，参考文献20篇

毕业论文关键词：不定根  甘薯  胞外核苷  ATP   ADP 

Effect of Extracellular Nucleotides on Adventitious Root Formation and Elongation in Sweet Potato seedlings 

Abstract Sweet potato stems are usually used in the field for reproducing and sometimes the survival rate of sweet potato seedlings is decreased under drought or salinity conditions because of the inefficiency of rooting. To investigate the factors affect the rooting ability in sweet potato cuttings, we explore the roles of extracellular nucleosides, which is important signaling molecules involved in multiple physiological processes, in sweet potato adventitious root formation and elongation. Our results showed that 0.1 mM ATP treatment group had obvious promoting effect on the root elongation, when the concentration of 5 mM, the root length showed significant inhibition, and the roots exhibited damaged condition. ADP treatment inhibited root elongation at all tested concentrations. 100 μM PPADS, which is an inhibitor of purinoceptors in animals, significantly inhibited the formation and elongation of sweet potato adventitious roots. However, 50 μM PPADS slightly promoting the elongation of adventitious roots. Based on our results, we concluded that extracellular ATP or ADP play important roles in regulating sweet potato adventitious roots formation and elongation but the detailed mechanisms still need further investigation. 

Key words:  adventitious roots  sweet potatoes  extracellular nucleosides   ATP   ADP 

目录

摘要 I

Abstract II

目录 III

图清单 IV

引言 5

1材料与方法 6

    1.1实验材料 6

    1.2 试验方法 6

2实验结果与分析 8

    2.1不同浓度ATP对甘薯幼苗不定根的影响 8

    2.2不同浓度ADP对甘薯幼苗不定根的影响 10

    2.3不同浓度PPADS对甘薯幼苗不定根的影响 12

3讨论