节节麦及人工合成多倍体中Glu—D1位点高分子量谷蛋白亚基组成及表达研究

为了了解节节麦及人工合成多倍体的Glu—D1位点高分子量谷蛋白亚基组成及表达情况，采用十二烷基磺酸钠-聚丙烯跣胺凝胶电泳(SDS-PAGE)，分析了4份节节麦及其在此基础上形成的人工合成多倍体高分子量走谷蛋白亚基(high—molecular-weight glutenin subunit,HMW-GS)的组成。研究结果表明，4份节节走AS60-1、AS60-2、AS77和AS2383在Glu—D1位点上出现了4种不同的亚基类型，分别为2 10、5 12、5 10和2．1 10；2份节节走人工加倍形成四倍体AS2390、AS2410的HMW—GS分别为2．1 10和5 10；3份节节麦-圆锥麦人工合成双二倍体RSP、SHW—L1及SHW—L2的HWM—GS分别为2^*、17 18、5 10；2^*、17 18、2 10和2 10。谷蛋白王基呈现了共显性遗传，表明节节麦高分子量谷蛋白基因能在人工多倍体情况下得到正常表达。本文还对利用节节麦优良基因的方式作了讨论。     

Variation in zinc efficiency among and within Aegilops species

Fifteen accessions of Aegilops tauschii (DD), 10 of Ae. speltoides (SS) and 8 of the tetraploid Aegilops species sharing the U genome were used to study the influence of varied zinc (Zn) supply on development of Zn-deficiency symptoms, and on shoot dry weight and Zn concentration. Plants were grown in a Zn-deficient calcareous soil under greenhouse conditions with (+Zn = 5 mg kg^—1 soil) and without (—Zn) Zn supply. Four accessions of wild tetraploid wheat, Triticum turgidum var. dicoccoides (BBAA), a group known for its high sensitivity to Zn-deficiency, were used in the experiments for comparison. As expected, the accessions of wild T. turgidum var. dicoccoides showed the highest sensitivity to Zn deficiency, and had more severe leaf symptoms of Zn deficiency (whitish-brown necrotic patches). Among the Aegilops species, leaf symptoms of Zn deficiency were, in general, more distinct in Ae. tauschii (DD) and least in Ae. speltoides (SS). Zinc efficiency, expressed as the percentage of shoot dry weight produced under conditions of Zn deficiency compared to Zn supply, averaged, 15% for T. turgidum, 32% for Ae. tauschii, 52% for Ae. speltoides and 61% for the tetraploid Aegilops species carrying the U genome. Differences in Zn efficiency among and within Aegilops species and T. turgidum were significantly correlated with the Zn amount per shoot, but not with the Zn amount per unit dry weight of shoots. The results show that Aegilops species can be exploited as an important genetic source for Zn efficiency genes, particularly Ae. speltoides var. ligustica (SS) and Ae. triuncialis (UUCC). Transfer of these genes to cultivated modern wheat may bring about a greater variation in Zn efficiency in wheat, and facilitate production of Zn-efficient modern wheat cultivars for Zn-deficient soil conditions.     

D2类山羊草细胞质普通小麦核代换系育性在不同光温条件下的差异

将D2类山羊草[粗厚山羊草（Ae.crassa)、牡山羊草（Ae.juvenalis)和瓦维洛夫山羊草（Ae.vavilovii)]细胞质普通小麦核代换系于1997－1998年分别种植在不同纬度的5个地点，并进行分期播种。从不同地点核代换系和核亲本的育性表现，分析D2类山羊草细胞质核代换系对日长、温度的敏感性及其差异。结果表明：（1）D2类山羊草细胞质小麦核代换系的3种类型存在差异，粗厚山羊草对日长、温度反应最为敏感，其次是瓦维洛夫山羊草，牡山羊草对光周期较钝感。（2）日长和温度两种生态因子对D2类山羊草细胞质核的育性变异的作用程度不同，日长是主控因子，温度在日长因子相近时方显示其作用。（3）核质互作是D2类山羊草细胞质小麦核代换系育性对光温反应的遗传方式。     

Expression of morphological and flowering time variation through allopolyploidization: an empirical study with 27 wheat synthetics and their parental Aegilops tauschii accessions

It was recently shown that allopolyploidy brings novel epistatic interactions to genes belonging to different genomes. However, systematic studies of the phenotypic relationships between synthetic hexaploid wheats and their parental lines have not been conducted. In this study, 27 synthetic hexaploid wheats were produced by crossing the tetraploid wheat cultivar ‘Langdon’ with 27 accessions of Aegilops tauschii. Variations in 20 morphological and flowering traits were analysed in both the synthetic wheat lines and the parental Ae. tauschii accessions. The 20 traits exhibited large variations in the wheat lines. For many of the traits, the degree of variation in the parental accessions was reduced in the hexaploid derivatives. Principal component analysis of floret‐related traits divided the Ae. tauschii accessions into two subspecies, ssp. tauschii and ssp. strangulata, but this parental pattern of subspecific division was not detectable in the hexaploids. Our results suggest that the ‘Langdon’ genome may have an alleviating effect on the expression of D‐genome‐derived variations in derived synthetics.     

盐胁迫对入侵植物节节麦与小麦竞争关系的影响

以节节麦为试材,采用盆栽控制试验,运用de Wit替代系列方法,研究不同浓度(0、50、100、200、400mmol/L)中性盐(NaCl)及碱性盐(Na₂CO₃)胁迫对其生长发育及与小麦竞争关系的影响。结果表明：不同盐胁迫均能抑制节节麦和小麦的生长发育,并造成2种植物的株高、叶面积及总生物量下降;节节麦和小麦均通过提高SOD活性及脯氨酸含量抵御不同盐胁迫,但随着处理浓度的增加,2种植物的相对电导率及硫代巴比妥酸(TBARS)含量均明显增加,表明盐胁迫对2种植物细胞膜损伤程度持续加剧;不同盐胁迫还导致了2种植物的叶绿素含量明显下降;从SOD活性、脯氨酸含量、相对电导率及TBARS含量的增幅以及叶绿素含量的降幅可知,同种盐胁迫对节节麦的损伤程度小于对小麦的,而Na₂CO₃对2种植物造成的伤害程度大于NaCl;从节节麦的竞争平衡指数(CB)可知,不同盐胁迫条件下节节麦的竞争能力依然大于小麦,但随处理浓度的增加呈先升后降的趋势。总之,通过形态结构及生理特性的调整,节节麦对不同种类盐胁迫均表现出了一定的适...     

易变山羊草两个y-型高分子量谷蛋白新亚基的鉴定及基因编码区分子克隆

利用 SDS-PAGE和分子克隆方法研究了易变山羊草的高分子量谷蛋白亚基及其基因。结果表明 ,四倍体易变山羊草有 3个可表达的高分子量谷蛋白亚基。其中一个亚基的迁移率很慢 ,推测其为 Glu-U1 x;另外2个亚基的迁移率分别与中国春的 Bx7和 By8接近或更慢 ,利用一对特异扩增基因编码区的引物得到的扩增片段长度分别为 2 .5 kb和 1 .9kb。分子克隆得到阳性质粒 p2 .5和 p1 .9。基因测序结果显示二者均为 y型高分子量谷蛋白基因 ,它们与普通小麦中已经报道的 y型高分子量谷蛋白基因在核苷酸和氨基酸序列上都存在差异 ,是 2个不同的高分子量谷蛋白新基因     

西尔斯山羊草紫色酸性磷酸酶PAP1基因的克隆及分析

旨在利用基因工程手段将AeSePAP1基因转入到小麦,为获得耐低磷胁迫的小麦品种奠定基础。以西尔斯山羊草的叶片为材料,根据小麦和二穗短柄草的PAP1基因设计特异引物,采用同源克隆的方法获得西尔斯山羊草紫色酸性磷酸酶PAP1基因的cDNA序列,并将其命名为AeSePAP1。该基因长1.03kb,编码335个氨基酸,分子质量为37.95ku,等电点为5.55。与小麦PAP1基因相比,西尔斯山羊草PAP1基因的cDNA的编码区有36处发生碱基替代,包括24处转换和12处颠换,有16处编码的氨基酸残基不同,其序列一致性达94.66%。对AeSePAP1基因编码的蛋白质进行生物信息学分析发现,该蛋白具有信号肽和跨膜结构,定位于质膜或分泌到胞外。系统进化树分析表明,西尔斯山羊草紫色酸性磷酸酶PAP1基因与普通小麦、短柄草、谷子的PAP1基因同源性较高。