大麦近等基因系苗期根系形态及叶片渗透调节物质对PEG胁迫的响应

发布时间：2018-03-26 19:37

本文选题：大麦　切入点：株高近等基因系　出处：《中国农业科学》2017年13期

【摘要】：【目的】研究大麦半矮秆基因uzu与抗旱性的关系,为大麦抗旱优质育种提供理论依据。【方法】以两套大麦株高近等基因系(3T、3D和15T、15D)为试验材料,采用营养液水培方式,以不同浓度的PEG6000模拟干旱胁迫,研究不同胁迫程度:对照(0)、轻度(5%)、中度(15%)和重度胁迫(25%)对大麦株高近等基因系幼苗株高、根冠比、根系形态及叶片渗透调节物质的影响。在幼苗长至四叶一心时取样,直尺测定株高;采用烘干称重法获得根系生物量和地上部生物量,二者比值乘以100%得到根冠比;利用根系扫描仪对样根进行扫描测量,并用Win RHIZO软件进行单株总根长、根表面积和根体积的分析;可溶性糖含量用硫酸-蒽酮比色法测定;可溶性蛋白含量用考马斯亮蓝G-250染色法测定;脯氨酸含量用酸性茚三酮显色法测定。【结果】随着PEG6000浓度的增加,大麦幼苗生长受到明显抑制,株高逐渐降低,而根冠比则呈相反的变化趋势。就根系形态而言,随胁迫程度的增加,两套近等基因系表现出不同的变化趋势,在轻度和中度胁迫下3D和15T的变化幅度分别小于3T和15D,在重度胁迫下则表现相反。可溶性糖含量随胁迫浓度的增加呈先升高后降低再升高的变化趋势,而可溶性蛋白含量变化趋势与可溶性糖含量相反;在轻度和中度胁迫下3D和15D的变化幅度分别小于3T和15T,在重度胁迫下也表现相反。但脯氨酸含量随胁迫浓度升高呈现上升趋势,且在不同胁迫浓度下均表现为3D和15D变化幅度较小。相关分析表明:不同胁迫处理下,除可溶性蛋白含量外,株高与其他性状均存在显著相关关系;根冠比与根系形态以及根系形态之间也存在显著相关关系。同时,具有较高可溶性糖含量的品系其脯氨酸含量也较高,而可溶性蛋白含量则较低。此外,根系形态与叶片渗透调节物质之间亦存在一定的相关性,即总根长和根表面积均与可溶性糖含量和脯氨酸含量呈现显著负相关关系。【结论】在根系形态及叶片渗透调节方面,大麦株高近等基因系对苗期不同干旱胁迫的响应存在差异并相互影响。在轻度和中度胁迫程度下,近等基因系3T和3D中半矮秆基因的存在有利于抵御干旱胁迫。
[Abstract]:[objective] to study the relationship between barley semi-dwarf gene uzu and drought resistance, and to provide theoretical basis for barley breeding for drought resistance and quality. Simulated drought stress with different concentrations of PEG6000 was used to study the effects of different stress levels on seedling height and root-shoot ratio of barley plant height and near isogenic line. The effects of root morphology and leaf osmotic regulatory substances on the root biomass and shoot biomass were obtained by measuring the plant height by measuring the plant height at the time of seedling growing to four leaves, and the root / shoot ratio was obtained by multiplying the ratio of root and shoot by 100%. The total root length, root surface area and root volume were analyzed by Win RHIZO software, and the content of soluble sugar was determined by sulfuric acid-anthrone colorimetry. The soluble protein content was determined by Coomassie brilliant blue G-250 staining and proline content by acid ninhydrin chromogenic method. [results] with the increase of PEG6000 concentration, the growth of barley seedlings was significantly inhibited and the plant height decreased. The root / shoot ratio showed a reverse trend. As for root morphology, with the increase of stress degree, two sets of near-isogenic lines showed different trends. The changes of 3D and 15T under mild and moderate stress were less than those of 3T and 15D, respectively, while under severe stress, the content of soluble sugar increased at first and then decreased and then increased with the increase of stress concentration. The change trend of soluble protein content was opposite to that of soluble sugar content. The changes of 3D and 15D under mild and moderate stress were less than 3T and 15T, respectively, but the proline content increased with the increase of stress concentration. The correlation analysis showed that there was a significant correlation between plant height and other traits except soluble protein content under different stress concentrations. There was also a significant correlation between root / shoot ratio and root morphology, and proline content was higher and soluble protein content was lower in the lines with higher soluble sugar content. There was also a significant correlation between root morphology and leaf osmotic regulatory substances, that is, the total root length and root surface area were negatively correlated with soluble sugar content and proline content. [conclusion] in root morphology and leaf osmotic regulation, there was a significant negative correlation between root morphology and leaf osmotic regulation. The responses of near isogenic lines of barley plant height to drought stress at seedling stage were different and interacted. Under mild and moderate stress, the existence of semi-dwarf genes in near isogenic lines 3T and 3D was beneficial to resist drought stress.
【作者单位】：河北农业大学生命科学学院;河北省作物生长调控实验室;河北农业大学农学院;
【基金】：河北省自然科学基金(C2011204016,C2015204066)
【分类号】：S512.3

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