水稻白条纹叶突变体st11的遗传分析与基因定位

白条纹叶突变体st11是从粳稻品种Kitaake组培过程中获得的。该突变体在分蘖前叶色表现为正常,从分蘖期开始新生叶表现为白条纹直至成熟期。与野生型相比,该突变体的分蘖、株高、结实率和千粒重等农艺性状没有发生明显变化。遗传分析表明该突变体白条纹叶性状受一对隐性核基因控制。利用该突变体分别与水稻02428、Jodan杂交构建了两个F2群体用于基因定位。通过集群分离分析(bulked segregant analysis)发现该基因位于第1染色体端粒附近,并与分子标记RM151和RM10080连锁。进一步利用更多分子标记分析F2群体,我们将该基因定位于I10和I26两个标记之间大约270kb的区间内。     

一个水稻苗期白条纹叶及抽穗期白穗突变体的鉴定和基因定位

从粳稻中花11组培后代中发现了一个苗期白条纹,抽穗期自穗的突变体.该突变体表现为1叶期叶全白,2叶期从新叶叶尖开始沿叶脉逐渐转绿,至成株期完全变绿,抽穗后内外颖表现为自色,穗轴和小枝梗表现为绿色,成熟后颖壳转黄.根据基因定位结果,将该突变体定名为wslwp(white striped leaf and white pa...     

Genetic Analysis and Mapping of a Thermo-sensitive White Stripe-Leaf Mutant at Seedling Stage in Rice (Oryza sativa)

A thermo-sensitive white stripe-leaf mutant(tws)was selected from the M2 progeny of a japonica variety,Jiahua 1, treated by 60 Coγ-radiation.In comparison with the wild type parent,the mutant displayed a phenotype of white stripe on the 3rd and 4th leaves,but began to turn normal green on the 5th leaf when grown at low temperatures(20°C and 24°C). Furthermore,the content of total chlorophyll showed an obvious decrease in the leaves with white stripe.These results suggest that the expression of the mutant trait was thermo-sensitive and correlated with the leaf age of seedlings.The genetic analysis indicated that the mutant trait was controlled by a single recessive nuclear gene,designated as tws.In addition,by using SSR markers and an F2 segregating population derived from the cross between the tws mutant and 9311, tws was mapped between the markers MM3907 and MM3928 with a physical distance of 86 kb on rice chromosome 4.     

水稻淡绿叶突变体HM133的遗传分析与基因定位

EMS诱导籼稻品种IR64获得淡绿叶突变体HM133。与野生型IR64相比,HM133播种后的第6周和第15周的光合色素含量以及抽穗期的净光合速率显著降低,气孔导度则明显上升;此外,突变体株高、每穗实粒数和结实率等农艺性状也较野生型显著下降。叶绿体超微结构分析表明,分蘖期HM133类囊体基粒片层形状不规则,堆叠凌乱、排列疏松。遗传分析表明HM133淡绿叶性状受单隐性核基因控制。通过分子标记将该基因定位于第3染色体长臂RM143和RM3684之间。该区间内包含编码镁螯合酶D亚基的基因OsCHLD。序列分析表明HM133中该基因第10外显子上有一个从G突变为A的单碱基变异,导致编码的氨基酸由精氨酸变成谷氨酸,推测OsCHLD基因即为控制HM133淡绿叶表型的候选基因。     

小麦白斑突变体I30的特征特性及遗传分析

类病斑突变体是研究植物程序性死亡和抗病性的理想材料。为了丰富小麦斑点突变体的研究,对叠氮化钠诱变小麦品种陕农33产生的稳定遗传的白斑突变体I30进行了特征特性研究和遗传分析。结果表明,突变体I30从三叶期开始表现白色块斑和长条纹。锥虫蓝染色和DAB染色显示,I30斑点处出现细胞死亡和H_2O_2积累现象。透射电子显微镜观察表明,I30的叶绿体形状发生改变,数目减少,基粒垛叠高度无序,部分甚至降解。农艺性状调查结果表明,I30的株高、单株有效穗数、穗粒数、穗长和结实率与野生型间无显著差异,但千粒重、穗粒重、单株产量、旗叶长度和宽度显著低于野生型。遗传分析表明,I30由1对隐性核基因控制。利用BSA+660K基因芯片技术,将该基因定位于小麦6D染色体上,位于SSR分子标记Xcfd190和6DS-5之间,遗传距离分别为6.4cM和9.1cM。     

Genetic Analysis of Streaked and Abnormal Floret Mutant st-fon

A double mutant with streaked leaf and abnormal floret was found and temporarily named streaked leaf and floral organ number mutant (st-fon).For this mutant,besides white streak appeared on culm,leaves and panicles,the number of floral organs increased and florets cracked.The extreme phenotype was that several small florets grew from one floret or branch rachis in small florets extended and developed into panicles.By using transmission electron microscope to observe the ultrastructure of white histocytes of leaves at the seedling stage,the white tissues which showed abnormal plastids,lamellas and thylakoids could not develop into normal chloroplast,and the development of chloroplast was blocked at the early growth stage of plastid.Scanning electron microscope and paraffin section were also used to observe the development of floral organs,and the results indicated that the development of floral meristem was out of order and unlimited,whereas in the twisty leaves,vascular bundle sheath cells grew excessively,or some bubbly cells increased.Genetic analyses carried out by means of cross and backcross with four normal-leaf-color materials revealed that the mutant is of cytoplasm inheritance.     

大麦黄绿叶色突变体ygl的农艺性状及其调控基因初步定位

叶色突变是植物界广泛存在的一种现象,突变株系是解析植物光合作用和光形态建成等过程的理想材料。大麦黄绿叶色突变体ygl是本课题组在鄂大麦934的EMS突变体库中筛选获得的,该突变体的叶色在整个生育期都较野生型浅,而且苗期呈现黄绿色,后期表现为浅绿色。与野生型相比,ygl株高和千粒重分别表现为极显著和显著降低,其它重要产量性状,如穗数、穗长和穗粒数等无显著变化。进一步分析发现,ygl苗期叶片中基粒类囊体严重线性化,叶绿体超微结构受损。以正常叶色大麦品种Harrington和黄绿叶色突变体ygl为亲本构建了F_2分离群体,对F_2群体及其衍生的F_(2:3)家系进行分析发现,该性状由一个隐性核基因控制,命名为HvYGL(yellowgreenleaf)。利用上述F_2群体,通过基于SSR的BSA法,将该基因初步定位在大麦3H染色体上12.7 cM的区间内,其中 Bmag0209、 EBmac0871和 Bmag603三个标记与黄绿叶色性状共分离。     

Genetic Analysis and QTL Mapping of Large Flag Leaf Angle Trait in Japonica Rice

Genetic segregation analysis for flag leaf angle was conducted using six generations of P1,P2,F1,B1,B2 and F2 derived from a cross of 863B(a maintainer line of japonica rice) and A7444(a germplasm with large flag leaf angle).Genotypes and phenotypes of flag leaf angle were investigated in 863B(P1),A7444(P2) and 141 plants in BC1F1(863B/A7444$$$$863B) population.An SSR genetic linkage map was constructed and QTLs for flag leaf angle were detected.The genetic map containing 79 information loci was constructed,which covers a total distance of 441.6 cM,averaging 5.6 cM between two neighboring loci.Results showed that the trait was controlled by two major genes plus polygene and the major genes were more important.Fifteen markers showed highly significant correlations with flag leaf angle based on single marker regression analysis.Two QTLs(qFLA2 and qFLA8) for flag leaf angle were detected by both composite interval method in software WinQTLCart 2.5 and composite interval method based on mixed linear model in QTL Network 2.0.The qFLA2 explained 10.50% and 13.28% of phenotypic variation,respectively,and was located at the interval of RM300 and RM145 on the short arm of chromosome 2.The qFLA8 explained 9.59% and 7.64% of phenotypic variation,respectively,and was located at the interval flanking RM6215 and RM8265 on the long arm of chromosome 8.The positive alleles at the two QTLs were both contributed from A7444.     

Simulating growth,development, and yield of tillering pearl millet: I. Leaf area profiles on main shoots and tillers

Pearl millet (Pennisteum americanum L.) is an essential crop in farming systems of the dry areas of the semi-arid tropics and its tillering habit is an important adaptive feature. This is the first paper in a series aiming at developing and validating a pearl millet simulation model that recognises tillers as functional entities, analogous to intercrops. The objective of this paper is to quantify the effects of total leaf number per axis (TLN), cultivar, plant density and axis number on parameters that are used to simulate potential leaf area per plant. Four cultivars with different phenology and tillering habit were grown under well-watered and well-fertilised conditions at two locations in India, covering a range of daylengths and plant densities. For selected plants, the area of fully expanded leaves was measured non-destructively. A bell-shaped function adequately described the relationship between individual leaf area and leaf position on an axis. Its shape was determined by the position (X₀) and area (Y₀) of the largest leaf and by the breadth and skewness of the leaf area profile curve. TLN affected all four parameters, although the association with Y₀ was weak. Cultivar only affected Y₀, suggesting that parameterising new cultivars is straightforward. The observed density effect confirmed that competition for light between axes started during stem elongation. The results highlighted the consistent differences between leaf area profiles of main shoots and tillers. For a high-tillering crop like pearl millet, modelling leaf area dynamics through individual leaves is justified, as this approach can potentially deal with cultivar and environmental effects on tillering.     

Genetic Analysis and Gene Mapping of Light Brown Spotted Leaf Mutant in Rice

A light brown spotted-leaf mutant of rice was isolated from an ethane methyl sulfonate (EMS)- induced IR64 mutant bank. The mutant, designated as lbsl1 (light brown spotted-leaf 1), displayed light brown spot in the whole growth period from the first leaf to the flag leaf under natural summer field conditions. Agronomic traits including plant height, growth duration, number of filled grains per panicle, seed-setting rate and 1000-grain weight of the mutant were significantly affected. Genetic analysis showed that the mutation was controlled by a single recessive gene, tentatively named lbsl1(t), which was mapped to the short arm of chromosome 6. By developing simple sequence repeat (SSR) markers, the gene was finally delimited to an interval of 130 kb between markers RM586 and RM588. The lbsl1(t) gene is likely a novel rice spotted-leaf gene since no other similar genes have been identified near the chromosomal region. The genetic data and recombination populations provided will facilitate further fine-mapping and cloning of the gene.     

水稻条斑和颖花异常突变体st fon的鉴定与遗传分析

 在水稻遗传转化过程中发现一个不含外源基因的条斑和颖花异常的双突变体,暂命名为st fon。该突变体除茎、叶、穗出现白条斑外,花器数目增多,颖花开裂。其极端表型为同一颖花中长出几朵小花或小花中枝梗伸长为花序。利用透射电镜对苗期叶片白色组织细胞超微结构进行观察,发现质体结构异常,不能发育成正常叶绿体所具有的片层和类囊体,叶绿体的发育阻断在质体发育早期。利用扫描电镜和石蜡切片对花器官形态发生过程进行观察,发现花分生组织生长具有无序和无限性。对扭曲的叶片石蜡切片观察,发现维管束鞘细胞过度生长,或一些泡状细胞增大。将突变体与4个叶色正常的材料进行杂交和回交,遗传分析表明突变性状呈细胞质遗传。     

一个水稻低温移栽白条纹突变体wltt的鉴定和基因定位

【目的】叶色突变相关基因的鉴定与克隆为研究叶绿体发育、叶绿素合成和光合作用等分子机制提供理论基础。【方法】从常规粳稻镇糯19杂交后代中分离出一个低温移栽后叶色转成白条纹的自然变异突变体,命名为wltt (white stripe leaf after transplanting at low temperature)。成熟期测定野生型和wltt的主要农艺性状,分别在苗期、移栽后15 d和同时期直播条件下测定新生叶片的色素含量并观察叶绿体的超微结构;将wltt和野生型正反交进行遗传分析;用wltt与籼稻9311杂交产生的F_2作为定位群体进行基因定位;采用RT-qPCR分析叶绿体发育、叶绿素合成和光合作用相关基因在野生型和wltt中的表达水平。【结果】wltt突变体在苗期表现正常绿色,移栽15 d后心叶出现白条纹叶表型,至分蘖末期心叶叶色恢复;而不经移栽,突变体不会出现白条纹叶。人工模拟实验表明该表型是由低温条件下根损伤引起的。与野生型相比,wltt突变体移栽后的新生叶色素含量显著降低,光合速率下降;同时株高变矮,穗长、剑叶长和每穗粒数均显著降低。叶绿体的超微结构显示,突变体的叶肉细胞中,仅少数细胞含有正常的叶绿体,其余大部分叶肉细胞不含叶绿体。进一步研究发现,突变体中部分光合系统相关基因和叶绿体发育相关基因表达下调,叶绿素生物合成相关的14个基因表达也下调。遗传分析表明,该突变性状受一对隐性核基因控制。利用wltt突变体/9311的F_2群体,将该基因定位于水稻第2染色体着丝粒附近853kb区间内。目前,该区间内没有叶色相关基因的报道。【结论】WLTT是低温条件下移栽调控叶片转色的关键基因,在叶绿体发育过程中发挥重要作用。     

弹性漆改善软木地板漆膜性能的研究

为了探明水稻营养生长阶段的衰老机制,鉴定了一个在抽穗期前多数叶片逐渐死亡的黄色水稻突变体。黄色衰老突变体表型特征为在分蘖期后,其绿色叶片基部随机出现斑点,并逐渐扩散至整个叶片。与之相反,野生型叶片在整个分蘖期均保持绿色。超微结构分析发现,水稻突变体叶片叶绿体类囊体膜和其他细胞器结构在不同衰老时期破裂,严重时导致细胞质皱缩。在叶片衰老过程中,突变体叶片光合活性、叶绿素含量和抗氧化酶活性发生不可逆转的下降。     

水稻白条纹叶及白穗突变体wlp6的鉴定与基因定位

目的 叶色突变体是研究水稻光合作用,叶绿素生物合成和遗传发育调控机理的重要材料。发掘水稻叶色突变体,是水稻功能基因组学研究的重要遗传基础。方法 在昌恢121中发现了一份白条纹叶及抽穗期白穗突变体,经过连续多代自交能稳定遗传,暂命名为wlp6(white striped leaf and white panicle 6)。在南昌分早、中和晚3季播种wlp6与野生型种子,考查了中稻与晚稻的部分农艺性状;测定3叶期、分蘖期、抽穗期叶片及颖壳的叶绿素含量;通过电镜观察抽穗期叶肉细胞发育情况。在光照培养箱中进行温光敏感实验;将wlp6与昌恢121及02428正反交,观察F₁植株表型,对F₂分离群体进行卡方测验,分析突变体遗传规律;以wlp6/02428衍生的F₂群体为材料,利用BSA法进行基因定位。结果 wlp6自第1片叶到成熟,叶片均呈白条纹,抽穗期颖壳及枝梗失绿,高温天气穗转绿。突变体株高、有效穗数和每穗粒数在早稻季和中稻季均显著低于野生型,晚稻季wlp6的结实率和千粒重也显著低降低。叶绿素含量测定表明,wlp6叶片叶绿素含量在不同生育期及不同季均显著低于野生型,早稻和晚稻季种植的wlp6颖壳叶绿素含量也比野生型低。电镜观察抽穗期的叶肉细胞发现,wlp6叶绿体数目减少,体积变小,没有分化出明显的片层结构。温光敏感实验表明,突变体对光照强弱钝感,叶色受温度和日照长短影响,随着温度升高和日照时间变长突变体叶绿素含量有上升趋势。遗传分析表明,该性状受隐性核基因控制,利用wlp6/02428得到的616个F₂单株将WLP6定位于第6染色体短臂InDel标记R-7与R-8间,物理距离137 kb,此区间预测了21个候选基因。经候选基因分析及测序发现,其中LOC_Os06g14620编码一个核糖核酸还原酶小亚基,编码区第142和158位碱基由T替换为C,第288位插入了碱基A,碱基的插入导致翻译提前终止,因此推测LOC_Os06g14620是WLP6的候选基因。结论 LOC_Os06g14620是已经克隆的白条纹叶基因St1的候选基因,推测WLP6与St1等位,但突变位点不同,且表型也有差异。     

水稻黄绿叶突变体ygl11(t)的生理特性和基因克隆

在水稻品种南粳41中发现了一个黄绿叶自然突变体,经过多代连续自交形成了稳定的突变系,命名为ygl11(t),ygl11(t)整个生育期叶片都表现为黄绿色。对苗期、分蘖盛期、齐穗期突变体和野生型的叶绿素含量进行测定,ygl11(t)的叶绿素含量是野生型的45.7%~74.7%,叶绿素a含量是野生型的55.2%~87.5%,叶绿素b含量是野生型的12.5%~25.3%,ygl11(t)的类胡萝卜素的含量是野生型的62.3%~97.0%。ygl11(t)在分蘖盛期的净光合速率显著高于野生型,花后10d,ygl11(t)的净光合速率比野生型略低。对突变体叶片中叶绿体的超微结构进行观察,发现突变体叶绿体内的类囊体基粒片层数目减少且严重扭曲变形。遗传分析表明,ygl11(t)叶色性状受1对隐性核基因控制。利用SSR分子标记将YGL11(t)初步定位在水稻第10染色体的长臂上,进一步利用新开发的InDel和CAPS标记将YGL11(t)定位在58.1kb的物理距离内。对该区段内存在的开放阅读框进行序列分析,发现突变体ygl11(t)中编码叶绿素a氧化酶(chlorophyll a oxygenase 1)基因(OsCAO 1)的第9个外显子存在2个碱基缺失,从而导致提前出现终止密码子,初步分析OsCAO1即为YGL11(t)的候选基因。     

Morphological Structure and Genetic Mapping of New Leaf-Color Mutant Gene in Rice (Oryza sativa)

Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurring leaf-color rice mutant, Baihuaidao 7, was analyzed. Mutant plants typically exhibited a green-white-green leaf-color progression, but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation. Prior to the appearance of white leaves, mutant plant growth, leaf color, chlorophyll content, and chloroplast ultrastructure appeared to be identical to those of the wild type. After the changeover to white leaf color, an examination of the mutated leaves revealed a decrease in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content, a reduction in the number of chloroplast grana lamella and grana, and a gradual degradation of the thylakoid lamellas. At maturity, the mutant plant was etiolated and dwarfed compared with wild-type plants. Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene. Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 × Jiangxi 1587 cross. The mutant gene was mapped to rice chromosome 11, positioned between InDel markers L59.2-7 and L64.8-11, which are separated by approximately 740.5 kb. The mutant gene is believed to be a new leaf-color mutant gene in rice, and is tentatively designated as gwgl.     

冬前镇压和灌溉对冬小麦灌浆期旗叶光合特性和叶绿体超微结构的影响

为明确冬前镇压和灌溉对冬小麦灌浆期旗叶功能的影响,以济麦22为材料,在2016-2017小麦生长季,对其进行冬前镇压+灌溉(C+I)、灌溉(I)和镇压(C)处理,以常规种植管理为对照(CK),研究不同冬前栽培措施对冬小麦灌浆期土壤微环境、旗叶光合特性和叶绿体超微结构以及最终产量和生物量的影响。结果表明,与CK相比,C、I及C+I处理都可提高麦田土壤含水量和土壤温度,可增加花后14～28d旗叶叶绿素相对含量(SPAD)、灌浆期旗叶最大光学效率(Fv/Fm)、净光合速率(Pn)和蒸腾速率(Tr),缓解旗叶SPAD、Fv/Fm、Pn和Tr在灌浆后期的下降,其中以C+I处理的效果最佳;灌浆中后期(花后21d),CK条件下小麦植株旗叶部分叶绿体呈圆形,大部分基粒片层变形且排列紊乱,可见较多的亲锇颗粒,但C+I、C和I处理下叶绿体的破坏程度降低,较多的叶绿体呈椭圆形,单位面积内叶绿体数和叶绿体基粒数提高,基粒片层较CK清晰且排列紧密,亲锇颗粒数量减少,其中C+I和I处理对叶绿体超微结构的改善作用大于C处理。这说明在本试验条件下,冬前镇压+灌溉较单独灌溉或镇压更有利于改善小麦灌浆期旗叶光合功能,缓解灌浆后期旗叶的衰老,促进小麦产量形成。     

水稻窄叶突变体nal10的鉴定与基因精细定位

利用EMS诱变粳稻品种武运粳7号获得一个新窄叶突变体nal10,该突变体在苗期表现出极窄叶和弱小的特征,在生殖期表现出矮化、窄叶、畸颖和不育的表型。组织解剖学分析表明,nal10的叶片窄化可能是由于叶片大脉和小脉数量减少造成的。遗传分析表明,该窄叶表型受一对隐性核基因控制。利用nal10与台中本地一号(TN1)构建的F₂群体,通过混合分离法,在第1染色体上找到3个紧密连锁的SSR标记(RM1287、RM562和RM5638)。进一步利用新发展的分子标记,最终将该基因定位在STS标记PK83和PK78之间的55.2 kb范围内,该区间共有8个开放阅读框。RT-PCR分析表明,NAL10的突变能够造成生长素生物合成、信号转导和运输基因转录水平的下降,因此NAL10是一个与生长素相关的窄叶新基因。这些结果为进一步克隆该基因、丰富水稻叶发育的遗传调控网络打下了基础。     

一个水稻分蘖角度突变体tac2的遗传分析和基因初步定位

  水稻散生突变体tac2是以恢复系缙恢10号为材料经甲基磺酸乙酯（EMS）化学诱变所得。该突变体苗期表型正常,分蘖期株型松散,分蘖角度较野生型显著增大,株高明显降低。外源赤霉素处理可以使该突变体株高恢复,但分蘖角度不受影响。遗传分析表明该突变性状受1对隐性主效基因控制。利用分子标记将该基因初步定位于第9染色体上的RM3320与RM201之间,遗传距离分别为19.2和16.7 cM。     

水稻黄绿叶突变体djyg的遗传分析与基因定位

在粳稻品种Dongjin大田种植过程中,发现一个黄绿叶自然突变体,命名为djyg。该突变体在苗期表现明显的黄绿叶表型,抽穗以后,叶色逐渐恢复正常。叶绿素含量测定结果表明,在苗期、分蘖盛期及抽穗期叶绿素b的含量分别下降53%、62%、36%。电镜结果表明,分蘖期突变体中基粒、类囊体垛堆凌乱、排列疏松,类囊体基质较为稀薄。qRT-PCR结果证实,PORA、Cab1R、PsbA的表达量在突变体中均较野生型明显下调。遗传分析结果表明,黄绿叶突变体djyg由一对隐性主效核基因控制,图位克隆确定该候选基因为编码叶绿素合成酶基因YGL1的一个新等位基因。该突变体未影响植株的主要农艺性状,可作为一个理想的表型标记应用于杂交稻育种工作中。