【作者】 张琴；

【导师】 王际睿；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2016， 硕士

【摘要】 种子休眠解除与萌发牵涉到许多生理生化过程,如信号转导与传递、酶的启动、基因的转录与翻译、激素调节、蛋白质的分解与合成、糖类代谢、储藏物质动员、细胞再生等。植物内源激素是植物体内自身合成,低浓度即可对植物的生长发育起着调节作用的有机化合物,主要有ABA、GAs、IAA等。在种子发育、休眠与萌发过程中,内源激素能通过多种信号途径影响种子内的各种生理生化变化,调节一系列酶的代谢,从而控制种子的发育、休眠与萌发。本研究利用20份小麦材料(10份易发芽材料和10份抗穗发芽材料),分析小麦种子吸胀的0到48小时内源激素(主要是内源GA3)的动态变化趋势,研究具有不同穗发芽抗性的小麦种子在吸水后48小时内内源GA3动态变化与种子萌发水平的关系。主要结果如下：(1)比较和评价了4种种子内源激素提取和纯化方法,通过对所得的峰型和回收率进行比较,建立了一种适合小麦种子内源激素提取的体系以及利用高效液相色谱法检测其含量的标准化方法。通过对提取与检测方法的评价、比较,最后确定了以Agilent C18 XBD反相色谱柱(250 mm × 4.5μm)为检测柱,柱温35℃,波长254nm,流动相V甲醇：V水(0.6%冰醋酸)=50%：50%,流速1ml/min,进样量20μL为检测条件的小麦内源激素的检测方法。(2)对小麦遗传材料进行穗发芽抗性鉴定,从中筛选出20份表型稳定的材料(10份抗穗发芽和10份易发芽),不同年度间同一种植点的发芽率相关度达0.986,但是由于环境差异造成同一年份不同种植点之间发芽率相对差异较大。(3)按照优化后的提取、纯化检测方法对筛选出的20份蜡熟期收获小麦萌发种子进行5个时间梯度(0h、6h、12h、24h和48h)的内源激素分析。结果显示,利用优化后的方法,可稳定检测到供试材料的内源GA3,且其变化趋势差异明显,但是仅从部分材料中检测到IAA和ABA。2014、2015年种植的抗穗发芽材料,内源GA3含量存在差异,但是它们随萌发时间而出现的变化趋势基本一致。在抗穗发芽材料中,除了AS661764和AS661712在2014和2015年间内源GA3变化趋势的相关性分别是0.571和0.527外,其它8份抗穗发芽材料的内源GA3的相关度都达到0.7以上；萌发开始的48小时内源GA3的变化趋势平缓略下降。在易穗发芽材料中,除了AS661335和AS661119在2014年和2015年内源GA3变化趋势的相关度较低外,其它8份易穗发芽材料的相关系数都达到0.9以上,且内源GA3的含量整体比抗穗发芽材料高,其中川农16、AS661619、AS661804、AS661145和AS661311内源GA3的变化呈下降趋势；AS661873、良麦4号、AS661030、AS661335和AS661119内源GA3含量在24小时后显著增加。通过对两年内源GA3含量的比较看出,在抗穗发芽材料中,萌发开始的48小时内源GA3的变化趋势平缓略下降；在易穗发芽材料中,内源GA3的含量整体比抗穗发芽材料高,部分材料在24小时后GA3含量显著增加。更多还原

【Abstract】 Seed dormancy breaking and germination process involve many biochemical and physiological process, such as signal transduction and transfer, activation of enzyme, expression of genes, hormonal regulation, synthesis and decomposition of protein, carbohydrate metabolism, mobilization of reserve substance, rapid cell regeneration. Plant endogenous hormones are compound in plant itself, and can regulate plant growth and development in low concentration, such as ABA, GAs and IAA. In the process of development, dormancy and germination of seeds, the endogenous hormones can through a variety of signaling pathways make corresponding response within the seeds on a variety of physiological and biochemical changes and adjust a series of metabolic enzyme, regulating the development, dormancy and germination of the seeds.The object of the research was to analysis the dynamic changes of endogenous hormones (mainly endogenous GA3) from 0 to 48h after water absorption using 20 Chinese wheat landraces (10 resistance to PHS wheat and 10 susceptibility to PHS wheat), in order to study the relationship of wheat between dormancy and the dynamic changes of endogenous GA3 during 48h after water absorption, providing the basis for wheat pre-harvest sprouting.The results are as follows:(1) By exploring the different detection methods of endogenous hormones and comparing the peak and recovery of 4 detection methods, establish a HPLC to be fit for testing wheat endogenous hormones. Comparing and evaluating the testing method, confirm the detection procedure. The detection procedure was as follows: select Agilent C18 XBD reversed-phase column(250 mm×4.5μm) as the detection column; Column temperature was 35℃;Wavelength was 254 nm; Proportion of mobile phase was Ⅴ (methyl alcohol): Ⅴ water(0.6% acetic acid)=50%:50%; Flow velocity was 1ml/min; Sample load was 20μL.(2) Identifying PHS of Chinese wheat landraces, screen out 20 Chinese wheat landraces (10 resistance to PHS wheat and 10 susceptibility to PHS wheat) which have stable phenotype. Correlation of germination rate in two years and the same area was up to 0.986; the germination rates had large difference in different planting area during the same years.(3) Analysis endogenous hormone for five time gradient using the methods which is optimized. As the results showed, the endogenous GA3 was detected in all wheat materials, but only some materials could detect IAA and ABA. In the dormant wheat, the dynamic change of endogenous GA3 made a big difference. In the wheat resisting to PHS, although content of the endogenous GA3 had very great difference, the variation tendency of endogenous GA3 was consistent. Planting in 2014 and 2015, except AS661712’s and AS661764’s correlation coefficients of variation tendencies of endogenous GA3 were 0.571 and 0.525 respectively, the other wheat resisting to PHS correlation coefficients of endogenous GA3 were over than 0.7. The variation tendencies of endogenous GA3 declined, and the content of endogenous GA3 was lowest in 48h. In the material susceptible PHS, except AS661335’s and AS661119’s correlation coefficients of variation tendencies of endogenous GA3 were 0.587 and 0.314 respectively, the other 8 materials correlations were over than 0.9 and the content of endogenous GA3 is higher than the content in the material resistance to PHS. The variation tendencies of CN16、 AS661619、AS661804、AS661145 and AS661311 went down; the variation tendencies of endogenous GA3 of AS661873、 Liangmai4、 AS661310、 AS661315 and AS661119 increased firstly and then decreased. Comparing the results in two years, variation trend of endogenous GA3 is gently and declining in wheat resistance to PHS; between the wheat susceptible PHS, the content of endogenous GA3 is higher than the content in the material resistance to PHS, and the content of endogenous GA3 signally increased.更多还原