盐胁迫下小麦新品系89122的抗氧化酶活性和内源ABA含量变化的研究

利用花粉管通道法获得的转基因耐盐小麦新品系89122和其受体“陇春13”,在盐胁迫处理下,测定盐胁迫后89122和“陇春13”无性细胞系的抗氧化酶活性的变化和脱落酸的变化,结果表明,89122较其受体“陇春13”能维持较高的SOD,POD,CAT活性,ABA含量明显高于受体。     

Evaluation and characterization of an endosperm-specific sbeⅡa promoter in wheat

Starch,the main component of the wheat grain,is the product of a complex biochemical pathway. The sbeⅡα gene plays a key role in controlling the synthesis of starch, in particular, the biosynthesis of amylopectin,in maturing wheat grain.To investigate its regulatory mechanisms and endosperm-specific expression pattern, the sbeⅡα promoter (3094 bp in length) was cloned using APCR and sequenced.The effect of a series of deletions was studied using a GUS transient assay system. Results showed that the 3094 bp sequence (sbe.g construct) exhibited full stable promoting activity and that the activities of 5′ or 3′ deletions reduced levels of GUS expression. Some constructs with internal deletions showed only weak activity, however,sbe.e, with a deletion from -1579—--1210 bp resulted in higher levels of expression than the full-length promoter sequence, sbe.g. This indicates that motifs such as the -300 bp element, G-box and/or P-box act as positive elements and are necessary in determining the promoter‘s endosperm-specific pattern and that negative repressor elements or motifs may also be present within the -1579—-1210 bp sequence. The age of wheate ndosperm tissue used in the GUS-transient assay system is shown to be of significant importance.     

冬春性小麦杂交世代主要性状配合力与杂种优势的研究

通过冬春性小麦杂交世代主要性状的配合力与杂种优势的研究表明:同一性状不同品种的一般配合力和特殊配合力相对效应存在较大的差异:特殊配合力效应值较高的组合,其杂种优势较强,杂种后代表现愈好,但还与亲本的一般配合力效应有关.因此在选择中必须注重亲本的一般配合力的选择.实践证明,京花2号和荆阿的殊特配合力效应虽表现稍差,但一般配合力效应较好,是两个具有较高利用价值的亲本.     

小麦花和花序分化过程中细胞内含物的变化

本文对小麦茎生长锥分化及花和花序发育过程中细胞内物质的变化进行了研究。其变化规律可总结为以下两方面:(1)DNA,RNA 和蛋白质分布的细胞区域基本一致,且都在发生新器官和迅速生长发育的原分生组织细胞中含量最丰富。(2)淀粉物质的大量积累都是向着迅速生长与发育的新器官方面转移,而且积累淀粉的细胞区域总是紧靠在原分生组织的后面,但不在原分生组织细胞中,穗轴上不同部位小穗及小穗上不同部位小花的发育状况与所获得的营养物质(主要是多糖)成正相关。     

大麦黄矮病毒（BYDV）外壳蛋白基因在小麦原生质体中的稳定转化

实验采用ＰＥＧ介导法转化小麦，用ＧＵＳ基因作为标志，用荧光法测定Ａｃｔｌ－ＧＵＳ、Ｅｍｕ－ＧＵＳ、３５Ｓ－ＧＵＳ三种质粒转化小麦细胞后的瞬间表达强度，以比较Ａｃｔｌ、Ｅｍｕ、３５Ｓ三种启动子在小表中的表达强度．结果表明，Ａｃｔｌ和Ｅｍｕ的强度大致相等，均比３５Ｓ强．采用Ｅｍｕ为启动子带ＢＹＤＶＣＰ基因的质粒和经改造过的Ａｃｔ１为启动子带有抗潮霉素选择标记基因的质粒共转化小麦“济南１７７”的原生质体．转化６ｄ后，用潮霉素进行筛选，最后得到两块抗潮霉素的愈伤组织，转化后４个月，经ＰＣＲ检测，证明ＣＰ基因已整合进一块愈伤组织的细胞基因组中．     

根癌农杆菌介导大麦Mlo反义基因转化小麦

应用含有大麦Mlo反义基因表达载体的根癌农杆菌菌株Agl Ⅰ，对3种基因型小麦(核生3号、烟优361、扬麦158)的愈伤组织进行了转化．从其中2种基因型获得23株转基因植株，有2株是白化苗，转化频率分别为1．9％(核生3号)和2．8％(扬麦158)．PCR及Southem分析表明，外源基因已整合进植物基因组．实验结果表明，筛选压力的存在对转基因植株的获得至关重要，在无筛选压力下未获得转基因植株．7棵转基因植株移栽至大田后正常结实．     

Transgene inheritance and quality improvement by expressing novel HMW glutenin subunit （HMW-GS）genes in winter wheat

The expression vector pBPC30, which carries the high molecular weight glutenin subunit (HMW-GS) 1Dx5 and 1Dy10 genes, was transferred into hexaploid winter wheat cv. Jinghua No. 1, Jing411 and Jingdong No. 6 explants of immature embryos and immature inflorescence by particle bombardment. A large number of resistant transgenic plants were obtained under the selection of herbicide bialaphos or phosphinothricin (PPT). Confirmed transgenic plants of To generation showed successful integration of HMW-GS genes and bar gene into the wheat genome. T1 generation of transgenic plants can resist 20--150 mg/L PPT.Protein analysis of T2 seed by SDS-PAGE showed that HMW-GS 1Dx5 and 1DylO genes were well expressed in offspring seed of transgenic lines by co-expression with or substitution of endogenous 1Dx2 or 1DylO. In one transgenic line, TG3-74, a new protein band between endogenous protein subunits 7 and 8 (marked as 8*) of glutenin appeared,but endogenous subunit 8 (encoded by 1By8 gene) was absent. Analysis of gluten rheological quality on seed proteins of 102 T3 plants showed that the sedimentation value of 5 transgenic lines (44.2149.0 mL) was remarkably improved,59.6%---64.3% higher than that of wild type Jinghua No. 1 and Jingdong No. 6, similar to bread wheat Cheyenne (48.0 mL). Analysis of dough rheological properties of transgenic lines showed that the dough stable time of 5 transgenic lines range from 16 to 30 min, whereas the dough stable time of wild type was only between 3--7 min. Our research suggests that introducing novel HMW-GS genes into wheat is an efficient way to improve its bread-making quality.     

紫外线辐射对小麦幼苗生长的影响

本文报道了紫外线辐射（日光和紫外灯照射）对小麦幼苗生长的影响。经过日光紫外辐射处理的小麦叶片和未处理的叶片的干物质重量分别是１４．３３％和１０．９０％。叶绿素含量分别是１．３４和１．２５ｍｐ／ｇ·ＦＷ；硝酸还原酶活性分别是１５．５２和９．５２μｇＮＯ２－／ｇ·ｈ。叶片中可溶性蛋白含量分别是２０．８４和１５．１５μｇ／ｇ·ＦＷ；叶片经冰冻后浸泡液的电导率分别是８４０和７４０μΩ／ｃｍ；叶片甲醇提取液的Ｏ．Ｄ３００分别是１．３９和１．２４，过氧化物同工酶的活性高于对照。经过紫外灯照射的材料和对照，上述指标也有相近的变化趋势。本文就紫外辐射对植物生长造成的影响进行了初步讨论。     

小麦耐甘露醇变异细胞系的离体筛选及植株再生Ⅰ

目的 离体筛选小麦耐甘露醇变异细胞系并再生植株。方法 以耐盐系小麦850512r的幼穗和幼胚为外植体诱导胚性愈伤组织。以所得到的胚性愈伤组织为起始材料，采用一步和多步正筛选法离体筛选耐甘露醇变异细胞系。结果 成功获得小麦耐甘露醇变异细胞系，并再生植株。结论 小麦耐甘露醇变异细胞系的离体筛选并再生植株成功，证明在细胞水平上筛选并获得具有潜在耐水分胁迫特性的小麦新品系是完全可能的。