水稻不同直链淀粉含量的遗传研究

本文采用单粒稻米作米质分析，研究了直链淀粉含量与亲本遗传特性，分析了微效基因、修饰基因对直链淀粉含量的影响，并讨论了育种的对策。     

籼型细胞质对粳稻杂交后代F1稻米品质的影响

为促进东北粳稻稻米品质遗传育种研究，本试验利用分子标记手段对东北粳稻细胞质进行籼粳类型鉴定，再以4份籼质粳核超高产粳稻与4份粳质粳核粳稻构建双列杂交群体，分别在沈阳和哈尔滨两地种植，分析籼型细胞质背景下杂交后代F₁稻米品质性状的变化特征。结果表明，筛选到4份超高产粳稻沈农265、沈农9741、辽粳454、沈农9816的细胞质为籼型；杂交后代F₁品质性状相关性分析得出，食味值与直链淀粉含量正相关，与蛋白质含量极显著负相关；稻米品质方差分析表明，与粳质粳核材料相比，籼质粳核材料稻米蛋白质含量低，加工品质、蒸煮食味值高。综上所述，相同核遗传背景下，籼质粳核基因互作可能有利于提高稻米品质和口感。     

水稻糯性的遗传分析

利用１个糯稻品种与４个直链淀粉含量分别为高、中、低及极低的非糯稻品种杂交，以研究直链淀粉含量的遗传。分析了亲本、Ｆ１、Ｆ２、Ｂ１Ｆ１及Ｂ２Ｆ１单粒种子的直链淀粉含量，发现不能合成直链淀粉的糯稻亲本与４个不同在链淀粉含量的非糯亲本之间，直链淀粉含量的差异是由一主效基因所控制。直链淀粉含量的基因剂量效应对分离方式和选择效果有很大影响。早期分离世代，可通过对胚乳外观的选择，提高对直链淀粉含量的选择效果。     

稻米直链淀粉和蛋白质含量对糙米重与外观品质性状间遗传相关性的影响

利用7个籼型不育系和5个籼型恢复系按不完全双列杂交方式配制杂交组合,采用包括胚乳、细胞质和母体植株基因效应的非条件和条件分析方法,研究了稻米直链淀粉和蛋白质含量对糙米重、稻米外观品质性状间遗传相关性的影响。结果表明,糙米重与稻米直链淀粉含量、蛋白质含量之间存在着显著或极显著的相关性,可以利用条件分析的方法排除直链淀粉含量或蛋白质含量对糙米重的影响,进而深入分析糙米重与稻米外观品质性状间存在的真实遗传相关性。条件分析结果表明,直链淀粉含量的表现会增大糙米重与糙米长、糙米宽、糙米厚间的基因型相关性,降低糙米重与糙米长宽比、糙米长厚比间的基因型相关性;蛋白质含量的表现除了对糙米重与糙米长厚比间的遗传相关性影响不大外,其他与直链淀粉含量的表现相反。不同遗传体系的条件相关分量表明,当排除了直链淀粉含量或蛋白质含量对糙米重的影响后,糙米重与外观品质成对性状间的条件相关分量会产生与非条件分析结果明显不同的变化,其中以细胞质主效应相关、母体加性主效应相关以及相应的环境互作相关等尤为明显。     

中国大麦种质资源直链淀粉含量分析

为了弄清中国大麦种质资源中直链淀粉含量的高低,为今后的糯大麦研究和育种提供参考,利用近红外反射光谱（NIRS）法对含糯性基因的167个中国代表性大麦品种的直链淀粉含量进行了测定。结果表明,在中国大麦中鉴定发现的糯大麦种质均属低直链淀粉糯大麦（以下简称低直糯大麦）,尚无一份是无直链淀粉糯大麦（以下简称无直糯大麦）材料。167份含糯性基因品种的直链淀粉含量变异范围为13.34%～38.23%,平均值为25.23%,标准差为4.18,变异系数为16.56%。品种内不同单株间直链淀粉含量不同,有的品种单株变异系数大,有的变异系数小。在28个品种中检测到直链淀粉含量小于15%的单株,其中在6个品种中共鉴定出7份材料,直链淀粉含量低于10%,可以在我国糯大麦育种和遗传等基础理论研究中优先利用。由于大麦品种间和品种内单株之间的直链淀粉含量存在很大差异,因此进行糯大麦种质资源鉴定筛选时,应在品种群体测定的基础上,进一步开展单株纯系繁殖鉴定;在杂交育种中选择糯大麦亲本时,不但要考虑备选品种的直链淀粉含量,还要考虑其个体基因型的遗传一致性。     

单粒稻米直链淀粉含量测定方法的研究

 本文提出一种米粒不经磨粉、煮沸,直接用冷碱液在30℃下糊化溶解后测定其直链淀粉含量的单粒稻米直链淀粉含量测定法。本法测得的结果与常规方法基本一致,并具有简便易行,工作量小,样品用量少等优点,可应用于稻米直链淀粉的生理和遗传方面的研究,为优质育种的后代筛选提供有效手段。     

早籼稻品质分析及其遗传初探

本文按照国家规定的优质食用稻米的标准和测定方法,分析了11个早籼稻品种(品系)的稻米外观品质、蒸煮品质和营养品质。结果表明,本组培育的乌珍1号、乌珍5号的多数品质性状和711、713的全部品质性状都达到了农牧渔业部优质食用稻米标准。在性状遗传方面胶稠度可能受一对主基因控制,硬对软为显性。粒长、粒型、直链淀粉、蛋白质含量受多基因控制属于数量性状遗传,并与环境互作。高、低直链淀粉含量的品种间杂交,可以得到中等直链淀粉的后代。     

利用Wx和fgr基因双功能性标记高效选育优质水稻保持系

对选取的13份籼型保持系进行直链淀粉含量和香味测定及分子标记(484/485和fgr-1F/1R)检测,筛选出宜香1B作为试验用分子育种优质供体亲本。配组Ⅱ-32B/宜香1B,F2代进行该双标记分离分析,结果表明,不仅F2单株间特异性谱带差别明显便于鉴别,且呈现出两对独立遗传基因分离模式。选取F2代484/485和fgr-1F/1R呈Ⅰ型(与宜香B相同的带型)和Ⅲ型(杂合带型)的优良单株,经F3～F6加代,并结合农艺性状(株型、播抽历期等)和稻米品质性状(粒型、垩白度、透明度等)鉴定和选择,在F6再利用484/485和fgr-1F/1R分子标记进行复测和验证,从而获得了一批株系内性状基本稳定、株型好、直链淀粉含量中等、具有香味、外观和蒸煮食用品质优良的高世代株系。经测交鉴定,发现其保持系株系比例约占75.5%。表明利用Wx和fgr基因功能性分子标记的早世代检测和辅助选择,结合常规优质保持系鉴定和选育方法,可以快速获得直链淀粉含量中等、香味、长粒型、透明、低垩白、较易糊化等综合性状较优的保持系。     

利用Wx和fgr基因双功能性标记高效选育优质水稻保持系

 对选取的13份籼型保持系进行直链淀粉含量和香味测定及分子标记（484/485和fgr 1F/1R）检测,筛选出宜香1B作为试验用分子育种优质供体亲本。配组Ⅱ 32B/宜香1B,F2代进行该双标记分离分析,结果表明,不仅F2单株间特异性谱带差别明显便于鉴别,且呈现出两对独立遗传基因分离模式。选取F2代 484/485和fgr 1F/1R呈Ⅰ型（与宜香B相同的带型）和Ⅲ型（杂合带型）的优良单株,经F3~F6加代,并结合农艺性状（株型、播抽历期等）和稻米品质性状（粒型、垩白度、透明度等）鉴定和选择,在F6再利用484/485和fgr 1F/1R分子标记进行复测和验证,从而获得了一批株系内性状基本稳定、株型好、直链淀粉含量中等、具有香味、外观和蒸煮食用品质优良的高世代株系。经测交鉴定,发现其保持系株系比例约占75.5%。表明利用Wx和fgr基因功能性分子标记的早世代检测和辅助选择,结合常规优质保持系鉴定和选育方法,可以快速获得直链淀粉含量中等、香味、长粒型、透明、低垩白、较易糊化等综合性状较优的保持系。     

稻米糊化温度和直链淀粉含量的简易测定法

采用2 mol/L的KOH进行糙米糊化,其糊化温度与标准方法测定结果相比,两者相关系数为0.932,达极显著水平;糊化后直接染色,样品直链淀粉含量与标准方法测定样品直链淀粉含量之间的相关系数为0.915,达极显著水平。该方法具有简便、高效并相对准确的特点,非常适合低世代材料的直链淀粉含量和糊化温度的快速鉴定。     

水稻杂种后代籽粒直链淀粉含量选择与品质和产量性状的关系

 选用4个稻米直链淀粉含量有显著差异的粳稻品种配制两个杂交组合（系选1号×通769和东农423×藤系180）,研究其杂交后代籽粒直链淀粉含量选择对品质和产量性状的影响。结果表明,籽粒直链淀粉含量选择对杂种后代蒸煮食味品质和产量相关性状有不同程度的影响,其影响程度因杂交组合及性状不同而异;在蒸煮食味品质性状中,淀粉黏滞性谱的崩解值和消减值受直链淀粉含量选择的影响较大,而在产量相关性状中抽穗期、单株有效穗数、结实率、单株粒重等受直链淀粉含量选择的影响相对较大;通过直链淀粉含量的连续定向选择可以从杂种后代中分出直链淀粉含量不同的后代,粳稻杂种后代低直链淀粉含量的定向选择效果优于高直链淀粉含量的选择效果,更容易得到超低亲的变异类型;直链淀粉含量的选择对杂种后代产量性状的影响较复杂,存在有利或不利的影响,低直链淀粉含量的选择将会导致单株粒重的下降。     

Relationship Between the First Base of the Donor Splice Site of Waxy Gene Intron 1 and Amylose Content in Yunnan Indigenous Rice Varieties

There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT-genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content (18.95% on average) than those with TT-genotype (all below 16%), but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 (P<0.01).     

云南地方稻种Wx基因第一内含子供体+1位碱基变异与直链淀粉含量的关系

应用PCR一步法对来自云南省14个地州、55个市/县的220个籼、粳地方稻种Wx基因第一内含子供体+1位碱基G/T进行了检测,同时用PCR Acc I酶切法对其中的101份进行验证,结果表明两种方法检测结果一致。根据G/T碱基将220个供试材料分为GG、TT两种基因型。云南地方稻种以GG型占优势,有164个,占74.5%;TT型有56个,占255%;籼稻中80.5%属GG型,粳稻中67.0%属GG型。GG型直链淀粉含量较高,平均18.97%,TT型较低,均低于16%, GG、TT基因型之间的平均直链淀粉含量差异极显著。G/T与直链淀粉含量存在密切的联系,其相关系数为0733**。GG型品种中有33个直链淀粉含量较低（3.91%～15.93%）,多数为来源于云南西南部傣族地区的品种。籼稻中的GG型或TT型品种与粳稻中的GG型或TT型品种间平均直链淀粉含量无显著差异,表明GG/TT基因型在籼粳不同遗传背景下直链淀粉表达无显著差异。     

Starch digestibility and the estimated glycemic score of different types of rice differing in amylose contents

Three types of rice cultivars (indica, japonica and hybrid rice) with four levels of amylose were selected for assessing variability in starch digestibility. A vitro enzymatic starch digestion method was applied to estimate the glycemic index in vivo based on the kinetics of starch hydrolysis in vitro. The results indicated that significant differences in term of glycemic response were observed in three types of rice. Amylose content had an obviously impact on the estimated glycemic score (EGS) value and resistant starch (RS) content. The contents of RS were increased with the increasing amylose in the same type of rice. Japonica rice was significantly lower in RS content compared to indica rice and hybrid rice with similar amylose. The high amylose rice cultivar ZF201, which was characterized by low major RVA parameters, i.e. peak viscosity (PKV), hot paste viscosity (HPV) and cool paste viscosity (CPV), were obviously higher in RS content and lower in EGS. The retrogradation of cooked rice led to a reduction of HI and EGS of all varieties. Starch hydrolysis tends to be more quick and complete for the waxy and low amylose rice than for the intermediate and high amylose rice.     

辽宁省稻米蒸煮品质性状研究

以近年来辽宁省审定的61个水稻品种为试材,对辽宁省水稻品种蒸煮品质性状的现状及性状间的关系进行了分析。结果表明:辽宁省水稻品种间蒸煮品质性状差异较大,碱消值、直链淀粉含量优质率较高,直链淀粉含量与胶稠度存在着显著正相关。高直链淀粉含量的品种易出现较低级别的碱消值,中、低直链淀粉含量的品种则易出现较高级别的碱消值,这可作为间接选择的依据。辽宁省稻米蒸煮品质改良的重点应放在选择中、低直链淀含量的品种,并协调直链淀粉含量与胶稠度之间的关系。     

氮肥用量和播期对优良食味粳稻直链淀粉含量的影响

以直链淀粉含量不同的半糯粳稻新品种(系)为材料,设置高氮(450kg/hm~2)、中氮(300kg/hm~2)、低氮(150kg/hm~2)和不施肥(CK)4个氮肥水平,分期播种并进行短日照处理,研究了氮肥用量和播期对优良食味粳稻直链淀粉含量的影响。结果表明,氮肥用量对优良食味粳稻的直链淀粉含量有显著影响,随着氮肥用量的增加,直链淀粉含量有降低的趋势,两年均以高氮处理的直链淀粉含量最低。播期对优良食味粳稻的直链淀粉含量也有显著影响,随播期的推迟,直链淀粉含量呈降低趋势,这主要与抽穗后6~15d的温度有关,高温可使直链淀粉含量提高。短日照处理的结果也证实了这一点。     

Crucial role of amylose in the rising of gluten- and additive-free rice bread

Gluten- and additive-free rice bread is suitable for consumption by individuals who are sensitive to gluten and prefer to avoid additives. Here, we prepared 100% rice bread, which is a gluten-free rice bread prepared in the absence of additives, using 19 rice flour samples containing amylose contents ranging from 9.6 to 22.3%. The amylose content was positively correlated with the specific volume of the 100% rice bread, whereas no correlation was observed between the protein content and the specific volume. The amylose content was also positively correlated with the specific volume of gluten-free rice bread prepared following protease treatment of the dough. The dough of 100% rice bread prepared from rice flour containing higher amylose contents was better stabilized during leavening than that prepared from rice flour containing a lower amylose content. It was therefore apparent that amylose plays an important role in the preparation of 100% rice bread with a high loaf volume through stabilization of the dough.     

合系4号5个低直链淀粉突变体的遗传分析

 对粳稻品种合系4号诱变产生的5个低直链淀粉突变体YM1、YM2、P152、P153、P154进行了遗传分析。这5个低直链淀粉突变体的低直链淀粉含量均受一对隐性基因控制,并具等位性,且与wx位点不等位。直链淀粉含量较高的YM1（10.50%)与其他4个低直链淀粉含量突变体杂交F2存在着由一对等位基因控制的分离现象,直链淀粉含量较高对较低表现为显性。     

Formulating low glycaemic index rice flour to be used as a functional ingredient

Amylose and resistant starch (RS) content in rice flour were manipulated. The experiment was conducted using a full factorial design. Rice flour with average amylose content of 20 and RS content of 0.5 g/100 g dry sample was fortified with pure amylose from potato and high RS modified starch to reach the final amylose content of 30, 40 and 50 and RS content of 2, 4 and 6 g/100 g dry sample. The fortified rice flours were examined for their gelatinisation properties, in-vitro enzymatic starch digestion and gel textural properties. It was found that amylose and RS significantly affect all the fortified rice flour properties (p < 0.05). High amylose and RS improved starch digestion properties, reducing the rate of starch digestion and lowering the glycaemic index (GI) values. Amylose had a more pronounced effect on the fortified rice starch properties than RS. In this study, the fortified rice flour which contained amylose and RS of approximately 74 and 9 g/100 g dry sample respectively was used to produce rice noodles. The noodles exhibited low GI values (GI < 55). However, amylose and RS affected the textures of rice noodles providing low tensile strength and break distance (extensibility).