玉米直链淀粉ae基因的遗传与杂种优势分析

通过对2个ae近等基因系、6个普通玉米自交系及其组配杂交组合的直链淀粉含量及千粒质量的测定,结果表明:含有ae基因的杂交种与ae同型自交系相比千粒质量显著提高,ae基因明显提高了杂种直链淀粉的含量;同时,发现ae近等基因系的α-淀粉酶活性,发芽势和发芽率比普通自交系低,而含有ae基因的杂交组合明显高于ae近等基因系和普通自交系,表现出了较强的的杂种优势.     

不同基因型高直链淀粉玉米的遗传效应

将3个ae基因供体亲本和8个普通玉米自交系进行回交转育,测定了自交系本身及其回交转育的BC1F1和BC1F2代的千粒质量和直链淀粉含量.结果表明,BC1F2与BC1F1相比,大多数组合的直链淀粉含量有一定程度的提高,但千粒质量有降低的趋势.在回交的早代材料中,千粒质量和直链淀粉含量无明显的相关性;不同的ae基因供体亲本在遗传背景不同的轮回亲本中的表达效果有很大的差别.     

特异性PCR在检测玉米高直链淀粉基因中的应用

根据ae基因序列设计了22对引物,利用这些引物对3个常规玉米自交系和3个具有aeae纯合基因型的高直链淀粉玉米自交系及它们的3个杂交种进行标记,筛选出一对引物并利用这对引物检测21个玉米杂交种,结果表明:这对引物可以将具有AeAe基因型的普通玉米与具有Aeae杂合基因型的普通玉米区分开来,为把普通玉米自交系快速改良为高直链淀粉玉米自交系提供了一种有效的技术。     

玉米ae基因的单核苷酸多态性分析

纯合隐性基因ae对提高玉米籽粒中直链淀粉含量具有重要作用。本研究根据已知的玉米ae基因序列,利用Oligo6.0软件设计了23对特异性引物,对选育高直链淀粉玉米群体的亲本进行特异性PCR,对扩增产物进行测序,结果发现:在ae基因的9067bp序列中发现了48个单核苷酸多态性位点(SNPs)和31个插入/缺失(In Dels)位点,单核苷酸多态性频率是1个SNP/188bp和1个In Del/292bp。     

生物技术在玉米育种中的应用

近年来生物技术在玉米育种中的应用取得了一定成果。通过转基因技术和SSR、AFLP分子标记的应用,加快了玉米研究进程,育成了抗虫、抗病、抗除草剂的玉米,有利于研究玉米群体遗传多样性,建立玉米杂种优势群,提高玉米QPM育种效率,缩短育种进程。但由于研究费用过高,基因技术与SSR标记缺乏有用的玉米基因,基因沉默现象也成为开展玉米生物技术育种的限制因素。随着生物技术的飞速发展及其研究的日趋成熟,在拓宽玉米自交系种质材料,提高杂交种抗逆、抗病性和产量,完善玉米转基因技术体系,发掘玉米高产、优质、高抗、高油、高直链淀粉基因并进行相关标记的定位等方面将发挥更大的作用,应用前景广阔。     

高直链玉米淀粉的理化特性研究

【目的】研究高直链玉米淀粉的理化特性,为高直链淀粉玉米新品种的培育及高直链玉米淀粉的产业化开发利用提供参考。【方法】以源自13份高直链淀粉玉米自交系和1份普通玉米自交系的籽粒为材料,研究了高直链玉米淀粉和普通玉米淀粉的淀粉粒表型特征、热特性、糊化特性、溶解度和膨胀势的差异。【结果】普通玉米淀粉中直链淀粉含量为27.72%;高直链玉米淀粉中直链淀粉含量为44.22%~78.81%,可分为Ⅳ、Ⅴ、Ⅵ、Ⅶ4个级别。SEM结果显示,随着直链淀粉含量的增加,A型淀粉粒形态由饱满光滑、有蜡质光泽的球体或多面体变为皱缩无光泽的不规则多面体,B型淀粉粒则由饱满光滑的小球体逐渐变为无蜡质光泽的椭圆形,直至扭曲成不规则颗粒。随着直链淀粉含量的升高,初始温度(To)、峰值温度(Tp)、最终温度(Tc)、温变范围(To-Tc)逐渐升高,焓变(ΔH)则逐渐降低。普通玉米淀粉有明显的粘度峰,糊化曲线呈现出典型的"双峰"特征,高直链玉米淀粉的粘度峰随直链淀粉含量的增加逐渐消失,曲线呈"S"型。普通玉米淀粉和高直链玉米淀粉的溶解曲线和膨胀曲线都显示了相同的趋势,但溶解度和膨胀势随直链淀粉含量的增加而显著降低。【结论】与普通玉米淀粉相比,高直链玉米淀粉在淀粉粒形态、热特性、糊化特性、溶解度和膨胀势等方面都表现出了不同程度的差异,且直链淀粉含量越高差异越大。     

高直链淀粉玉米研究进展与发展前景

综述了高直链淀粉玉米遗传机理及基因的表达,育种方法及育种面临的挑战,高直链淀粉玉米的应用能值和发展前景。     

爆裂玉米主要品质性状的配合力研究

本文以九个爆裂玉米自交系,用完全双列杂交组配了36个组合进行试验,按Griffing 的方法Ⅳ模型Ⅱ估算了这些自交系及其杂交组合的若干品质性状的配合力、遗传力、相关性等。研究表明,膨胀倍数的一般配合力与总淀粉、直链淀粉、爆花率的一般配合力呈显著的正相关;爆花率与总淀粉呈显著负相关;狭义遗传力大小顺序为爆花率>直链淀粉>膨胀倍数>总淀粉;膨胀倍数、爆花率、直链淀粉和总淀粉都以基因加性效应为主。     

高直链淀粉玉米研究进展

综述了高直链淀粉玉米的应用价值 ,国内外研究现状 ,淀粉修饰基因的遗传修饰作用 ,育种中存在的问题以及育种方法 ,展望了高直链淀粉玉米的发展前景     

用反义RNA技术创造高直链淀粉玉米材料

 【目的】利用反义RNA技术调控玉米淀粉的生物合成过程,创造高直链淀粉玉米材料。【方法】克隆玉米淀粉分支酶(sbe2a)基因片段,以载体pWGLL为基础,构建高效反义表达载体,通过花粉管通道法将其导入玉米自交系铁7922中。【结果】获得了4株转基因株系,GFP表达检测、PCR扩增和Southern杂交结果表明,目的基因已整合到基因组中,且能够遗传。对4株转基因植株进行RT-PCR和淀粉分支酶活性检测,结果表明转反义sbe2a玉米淀粉分子酶基因的转录受到了明显抑制,淀粉分支酶活性明显低于野生型,相差最多的降低79.4%;直链淀粉含量也发生明显的变化,最高的提高了84.3%,且总淀粉含量与对照之间基本没有差异。【结论】采用反义RNA技术通过沉默内源sbe2a,可获得高直链淀粉含量的玉米材料。     

转反义蜡质基因纯合株系间直链淀粉含量与RVA谱关系分析

 【目的】排除以往水稻亚种或品种间RVA谱分析时存在着的遗传背景差异,分析转反义蜡质基因不同直链淀粉含量纯合株系间RVA各特征值的差异,更清楚地揭示直链淀粉含量与RVA谱特征值的关系。【方法】采用根癌农杆菌介导共转化和花药培养相结合的方法,培育含有反义蜡质基因的花培纯系,并对各株系进行直链淀粉含量和RVA谱测定和分析,通过比较RVA谱曲线图形及RVA谱特征值的显著性测定,分析相同遗传背景条件下直链淀粉含量对各RVA谱特征值的作用。【结果】在武运粳7号转基因后代中,获得了只含反义蜡质基因、不含潮霉素抗性标记的花培株系77个,经T1H1和T1H2二代直链淀粉含量测定,有19个株系的直链淀粉含量接近对照（对照16.0%）;有50个株系直链淀粉含量比对照下降1%～5%,其中,直链淀粉含量在11.0%～13.9%有30个株系;另外,有8个株系的籽粒为蜡质状,直链淀粉含量降至3.1%～4.0%。不同直链淀粉含量纯系间RVA谱分析发现存在二种RVA谱曲线图形,直链淀粉含量在3.1%～4.0%株系明显不同其它株系,也不同于常规糯稻;对RVA谱曲线图形相同、直链淀粉含量不同的株系进行分类比较,低直链淀粉含量株系的RVA谱曲线最终表现为曲线逐步上升,但没有超越第1个峰值。对不同直链淀粉含量株系类群的各RVA谱特征值进行显著性测定,3.1%～4.0%株系群有5个特征值与其它二个株系群存在极显著差异;11.0%～13.5%株系群有3个特征值与对照16.0%组存在极显著差异;直链淀粉含量与RVA谱各特征值之间优化数学模型显示：峰值时间和消减值与直链淀粉含量关系较为密切。【结论】导入反义蜡质基因,能导致直链淀粉含量降低;通过花药培养能快速获得纯合株系;直链淀粉含量差异不仅影响到各RVA谱特征值,而且还造成RVA谱曲线不同。     

Determination of Amylose Content and Its Relationship with RVA Profile Within Genetically Similar Cultivars of Rice(Oryza sativa L.ssp.japonica)

Anther culture pure lines with antisense Wx gene were generated by Agrobacterium tumefaciens-mediated co-transformation followed by anther culture in transgenic rice(Oryza sativa L.ssp.japonica).The antisense Wx transgenic pure lines were used to analyze the differences and the relationship between RVA eigenvalues among the lines with different amylose contents.77 pure lines of anther culture having antisense Wx gene were studied for the amylose content of its offspring cultivar,Wuyunjing 7.It was found that levels of amylose content were similar to the control in 19 lines(16.0%);1-5% lower than control in 50 lines,of which,within 11.0-13.9% in 40 lines;and 3.1-4.0% in 8 lines.The effect of the amylose content on RVA eigenvalue was analyzed through the RVA profile graphic comparison and test of significance for RVA eigenvalues.The analysis of RVA profiles with different amylose contents indicated that there were two kinds of RVA profiles within genetically similar cultivars.The lines with 3.1-4.0% of amylose content were distinctly different from other lines and conventional glutinous rice.The comparison of the similarity curve of RVA profile of the lines with different amylose contents showed that the lines with lower amylose content had a distinguished RVA profile with the curve increasing gradually,but not exceeding the first apex.The test of significance for eigenvalues of the RVA profile in the lines with different amylose contents indicated that there were five eigenvalues remarkably different among the lines with 3.1-4.0% of amylose content compared with other two groups.Further,there were three eigenvalues remarkably different among the lines with 11.0-13.5% of amylose content compared with control group.An optimized mathematical model,which characterizes the relationships between the amylose content and RVA eigenvalue,has been established in this study.From this model,it was clearly indicated that the parameters PeT and SBV were more related to amylose content.It was concluded that the differences in amylose content not only affected the eigenvalues of RVA but also caused different RVA profiles within genetically similar cultivars.The introduction of antisense Wx gene could lead to reduce the amylose content and lay theoretical foundation for quality improvement in rice breeding programs.     

Determination of Amylose Content and Its Relationship with RVA Profile Within Genetically Similar Cultivars of Rice (Oryza sativa L.ssp.japonica)

Anther culture pure lines with antisense Wx gene were generated by Agrobacterium tumefaciens-mediated co-transformation followed by anther culture in transgenic rice (Oryza sativa L.ssp.japonica).The antisense Wx transgenic pure lines were used to analyze the differences and the relationship between RVA eigenvalues among the lines with different amylose contents.77 pure lines of anther culture having antisense Wx gene were studied for the amylose content of its offspring cultivar,Wuyunjing 7.It was found that levels of amylose content were similar to the control in 19 lines (16.0%);1-5%lower than control in 50 lines,of which,within 11.0-13.9% in 40 lines;and 3.1-4.0% in 8 lines.The effect of the amylose content on RVA eigenvalue was analyzed through the RVA profile graphic comparison and test of significance for RVA eigenvalues.The analysis of RVA profiles with different amylose contents indicated that there were two kinds of RVA profiles within genetically similar cultivars.The lines with 3.1-4.0% of amylose content were distinctly different from other lines and conventional glutinous rice.The comparison of the similarity curve of RVA profile of the lines with different amylose contents showed that the lines with lower amylose content had a distinguished RVA profile with the curve increasing gradually,but not exceeding the first apex.The test of significance for eigenvalues of the RVA profile in the lines with different amylose contents indicated that there were five eigenvalues remarkably different among the lines with 3.1-4.0% of amylose content compared with other two groups.Further,there were three eigenvalues remarkably different among the lines with 11.0-13.5% of amylose content compared with control group.An optimized mathematical model,which characterizes the relationships between the amylose content and RVA eigenvalue,has been established in this study.From this model,it was clearly indicated that the parameters PeT and SBV were more related to amylose content.It was concluded that the differences in amylose content not only affected the eigenvalues of RVA but also caused different RVA profiles within genetically similar cultivars.The introduction of antisense Wx gene could lead to reduce the amylose content and lay theoretical foundation for quality improvement in rice breeding programs.     

The effect of amylose on kernel phenotypic characteristics,starch-related gene expression and amylose inheritance in naturally mutated high-amylose maize

High-amylose maize starch has great potential for widespread industrial use due to its ability to form strong gels and film and in the food processing field, thus serving as a resistant starch source. However, there is still a substantial shortage of high-amylose maize due to the limitation of natural germplasm resources, although the well-known amylose extender(ae) gene mutants have been found to produce high-amylose maize lines since 1948. In this context, high-amylose maize lines(13 inbreds and 18 hybrids) originating from a natural amylose mutant in our testing field were utilized to study the correlation between amylose content(AC) and phenotypic traits(kernel morphology and endosperm glossiness), grain filling characteristics, gene expression, and amylose inheritance. Our results showed that AC was negatively correlated with total starch content but was not correlated with grain phenotypes, such as kernel fullness, kernel morphology and endosperm glossiness. Maize lines with higher amylose had a greater grain filling rate than that of the control(B73) during the first 20 days after pollination(DAP). Both starch debranching enzyme(DBE) groups and starch branching enzyme IIb(SBEIIb) groups showed a greater abundance in the control(B73) than in the high-amylose maize lines. Male parents directly predicted AC of F_1, which was moderately positively correlated with the F_2 generation.     

Determination of Amylose Content and Its Relationship with RVA Profile Within Genetically Similar Cultivars of Rice （Oryza safiva L. ssp. japonica）

Anther culture pure lines with antisense Wx gene were generated by Agrobacterium tumefaciens-mediated co-transformation followed by anther culture in transgenic rice （Oryza sativa L. ssp. japonica）. The antisense Wx transgenic pure lines were used to analyze the differences and the relationship between RVA eigenvalues among the lines with different amylose contents. 77 pure lines of anther culture having antisense Wx gene were studied for the amylose content of its offspring cultivar, Wuyunjing 7. It was found that levels ofamylose content were similar to the control in 19 lines （16.0%）; 1-5% lower than control in 50 lines, of which, within 11.0-13.9% in 40 lines; and 3.1-4.0% in 8 lines. The effect of the amylose content on RVA eigenvalue was analyzed through the RVA profile graphic comparison and test of significance for RVA eigenvalues. The analysis of RVA profiles with different amylose contents indicated that there were two kinds of RVA profiles within genetically similar cultivars. The lines with 3.1-4.0% of amylose content were distinctly different from other lines and conventional glutinous rice. The comparison of the similarity curve of RVA profile of the lines with different amylose contents showed that the lines with lower amylose content had a distinguished RVA profile with the curve increasing gradually, but not exceeding the first apex. The test of significance for eigenvalues of the RVA profile in the lines with different amylose contents indicated that there were five eigenvalues remarkably different among the lines with 3.1-4.0% of amylose content compared with other two groups. Further, there were three eigenvalues remarkably different among the lines with 11.0-13.5% of amylose content compared with control group. An optimized mathematical model, which characterizes the relationships between the amylose content and RVA eigenvalue, has been established in this study. From this model, it was clearly indicated that the parameters PeT and SBV were more related to amylose content. It was concluded that the differences in amylose content not only affected the eigenvalues of RVA but also caused different RVA profiles within genetically similar cultivars. The introduction of antisense Wx gene could lead to reduce the amylose content and lay theoretical foundation for quality improvement in rice breeding programs.     

黄瓜ZYMV抗性鉴定与抗性基因的分子标记辅助选择

近年来,小西葫芦黄化花叶病毒(zucchini yellow mosaic virus,ZYMV)在黄瓜(Cucumis sativus L.)上危害愈发严重,影响黄瓜植株的生长发育,降低黄瓜的产量与品质。由于ZYMV缺乏有效的防治药剂,因此需要培育ZYMV抗性黄瓜品种。以ZYMV Z5-1为病毒源,对不同黄瓜材料的ZYMV抗性进行鉴定,并对抗性位点候选基因进行了测序分析。结果显示,黄瓜品种SA02、SA06、S94、S1003、WI7230与TMG-1具有ZYMV抗性,其抗性候选基因Csa6G152960.1的突变位点一致。在ZYMV抗性鉴定的基础上,通过回交转育,将黄瓜自交系TMG-1中的ZYMV抗性基因转入感病自交系SA0422中,回交期间利用分子标记对回交群体进行前景选择和背景选择,经过3代回交,将ZYMV抗性基因转入SA0422,为培育抗ZYMV黄瓜新品种奠定了基础。     

花粉介导法将水稻OsSIK1基因导入玉米自交系的研究

采用超声波辅助的花粉介导法,将含有OsSIK1基因的植物表达载体导入3个玉米自交系中,在当代直接得到了T0转化处理种子。卡那霉素筛选和PCR检测表明,外源基因已整合到玉米基因组中。通过对这3个自交系的转化处理结实率、转化率和导入基因遗传率的比较分析,证明花粉介导法对不同自交系品种的转化率之间存在差异,从而得出自交系品种郑58和昌7-2更适合采用花粉介导法进行遗传转化。