Characterization of Fertility Alteration in 8 Environment-sensitive Genic Male-sterile Lines of indica Rice

Eight indica ( Oryza sativa L.) environment-sensitive genic male-sterile (EGMS) lines, 2-2S, K1405S, F131S, 2136S, Pei-Ai 64S, 1290S, GD-IS and N17S, were sequentially seeded with 10-15 d interval at three sites, Wuhan in 1997, Guiyang in 1997 and Sanya in 1997 and 1998, China. The results of investigations on self-sterilities showed that all of eight EGMS lines had stable sterile periods of longer than 30 d at Wuhan. They can be used for seed production of two-line hybrid rice, but can not reproduce themselves. Their stable sterile periods were shorter than 30 d at Guiyang, they can reproduce themselves and can not be used for hybrid seed production. In Sanya, their stable sterile periods were longer than 150 d, all of eight lines can be used for seed production in summer and autumn and reproduce themselves in winter. The fertility of all eight lines were sensitive to temperature. The sensitive stages, sensitive duration and critical point of temperatures (CPT) of fertility alteration in various lines were different. The sensitive stages of 2-2S and K1405S were from 18 d to 9 d before heading, the sensitive durations were 7-10 d and the CPTs were 23.7-24.5 degreesC. The sensitive stage, sensitive duration and CPT of F131S were from 17 to 5 d before heading, 13 d and 24.3-24.7 degreesC, respectively. The sensitive stage, sensitive duration and CPT of 2136S were from 18 to 12 d before heading, 7 d and 24.6-25.1 degreesC:, respectively. The sensitive stages, sensitive durations of Pei-Ai 64S, 1290S, N17S and GD-1S were from 24 to 13 d before heading and 10-13 d. And their CPTs were 24.6-25.1 degreesC, 25.5-26.2 degreesC, 25.4-26.1 degreesC,, and 24.1-24.7 degreesC, respectively.

Study on High-Eefficient Breeding Technology Platform of Dwarf Male-Sterile Wheat

[Purpose] The paper is to discuss the high-efficient breeding technology platform of dwarf male-sterile wheat.[Method] Conclusion was made upon the development of the creation and application of dwarf male-sterile wheat,and the conception of introducing haploid breeding technology into the technological system of high-efficient breeding of dwarf male-sterile wheat was proposed.[Result] Dwarf male-sterile wheat not only retains the properties of total male abortion of Taigu Genetic Sterile Wheat,steady sterility,and high hybrid rate after open pollination,but also has the characteristic of high dwarfing ability of Aibian No.1,becoming a comparatively ideal population modification means.At present,the application of dwarf male-sterile wheat mainly includes germplasm resources platform of population modification by using dwarf male-sterile wheat,technology platform of constructing new high-efficient breeding system by using dwarf male-sterile wheat,and production platform of using dwarf male-sterile wheat to breed new varieties.Through the introduction of haploid breeding into the already established wheat high-efficient breeding system,a new system of high-efficient biological breeding technology of dwarf male-sterile wheat was constructed theoretically.[Conclusion] The study provides references to the further study and application of dwarf male-sterile wheat.

Electron-Microscopic Study of Microsporogencsis in Male-sterile and Male-fertile Grain Amaranth(Amaranthus hypochondriacus L.)

A comparative study of microsporogenesis in male-sterile and male-fertile grain amaranth was conducted using electron-microscopy.The onset of microsporogenesis breakdown in male-sterile is at the mononuclear pollen stage following the release of microspores from tetrads.Abnormality in the behavior of degenerated tapetum was observed, which failed to envelope individual microspores after their release, leading to an abnormal vacuolation in the mononuclear pollen grains.As a result, the normal thickening of pollen wall could not occur and pollen grains could not engorge, causing male sterility.

Brassinosteroids mediate the effect of high temperature during anthesis on the pistil activity of photo-thermosensitive genetic male-sterile rice lines

Brassinosteroids(BRs)play critical roles in a wide range of plant developmental processes.However,it is unknown whether and how BRs mediate the effect of high temperature(HT)stress during anthesis on the pistil activity of photo-thermosensitive genetic male-sterile(PTSGMS)rice(Oryza sativa L.)lines.This study investigated the question.Three pot-grown PTSGMS rice lines were subjected to HT stress during anthesis.The contents of 24-epibrassinolide(24-EBL)and 28-homobrassinolide(28-HBL),the major forms of BR in rice plants,and levels of reactive oxygen species(ROS)or antioxidants(AOS),hydrogen peroxide(H2O2),1-aminocylopropane-1-carboxylic acid(ACC),ascorbic acid(AsA),and catalase activity in pistils,were determined.HT stress significantly reduced the contents of both 24-EBL and 28-EBL relative to those under normal temperatures,but the reduction varied by PTSGMS line.A line with higher BR contents under HT stress showed lower contents of ACC and H2O2,higher catalase activity and AsA content in pistils,and higher fertilization rate,seed-setting rate,and seed yield when the line was crossed with a restorer line,indicating that higher levels of BRs increase HT stress resistance.Applying 24-EBL,28-HBL or an inhibitor of BR biosynthesis confirmed the roles of BRs in response to HT stress.The results suggest that BRs mediate the effect of HT stress on pistil activity during anthesis and alleviate the harm of HT stress by increasing AOS and suppressing ROS generation.

Genetic Analysis and Preliminary Mapping of a Highly Male-Sterile Gene in Foxtail Millet(Setaria italica L.Beauv.) Using SSR Markers

Breeding of male-sterile lines has become the mainstream for the heterosis utilization in foxtail millet,but the genetic basis of most male-sterile lines used for the hybrid is still an area to be elucidated.In this study,a highly male-sterile line Gao146A was investigated.Genetic analysis indicated that the highly male-sterile phenotype was controlled by a single recessive gene a single recessive gene.Using F 2 population derived from cross Gao146A/K103,one gene controlling the highly male- sterility,tentatively named as ms1,which linked to SSR marker b234 with genetic distance of 16.7 cM,was mapped on the chromosome VI.These results not only laid the foundation for fine mapping of this highly male-sterile gene,but also helped to accelerate the improvement of highly male-sterile lines by using molecular marker assisted breeding method.

Differences in Nuclear DNA Between Male-Sterile and Male-Fertile Lines of Sorghum bicolor

Cytoplasmic male sterility(cms)is determined by nuclear-cytoplasmic interactions. Up to now, most studies are focused on the comparison of cytoplasmic DNAs of male-sterile lines and male-fertile lines, and analysis of nuclear DNA has not been documented yet. In order to find out the possible difference in nuclear genome of male-sterile line A1 Tx623 and corresponding male-fertile line Tx623 of sorghum, random amplified polymorphic DNA(RAPD)approach was used to analyze their cytoplasmic and nuclear genomes. Total DNAs of them were amplified at first to screen primers, which were able to generate reproducible bands specific to male-sterile line or male-fertile line. Then the selected primers were used to amplify their mitochon-drial DNA(mtDNA)and chloroplast DNA(cpDNA). The origins of all the polymorphic fragments were analyzed. After ruling out those amplified from cytoplasmic DNA, seventeen polymorphic fragments were determined to be amplified from nuclear DNA. These fragments originated from nuclear DNA indicate that differences in sequence exist between the nuclear DNA of male-sterile line and male-fertile line of sorghum, which do not agree with the traditional standpoint that they have identical nucleus.

Utilization of recessive male-sterile lines in soybean

Three male-sterile soybean (MS) groups were selected out through various methods. A number of filial generations and hybrid strains with special characters were obtained by the methods of isolated plot and backcross. Among them Jinping 1 and Jinping 2, two sister lines,with higher production,big and pretty seed,green coat and a rich perfume,are suitable to a vegetable in city. It was proved that the MS have wide utilization potential as follows; (a)the MS could solve a lot of troubles of artificial cross ;for instance,the green seed coat can be used as a gene marker; (b)the MS showed a high hybrid vigor and its potential ratio ranged from 132% to 347% ;and (c)the effects of recurrent selection of MS were obvious and the characters of yield of F5 in 18 strains were higher than that of F3.

Studies on the Recross Heterosis Effect of Male-sterile Single-hybrids in Corn

Re-cross was conducted between five ES cytoplasm male-sterile hybrids and four high-oil hybrids, and five normal hybrids, respectively. The oil content, yield, 1000-kernel weight and kernel size were estimated. Results were as follows: The average kernel oil content in the male-sterile hybrid ×high-oil hybrid was 1.6% higher than that of the female parent. The xenia effect value of oil genes was 0.30. The yield and 1000-kernel weight of male-sterile hybrids were 10.1% and 5.8% higher than that of corresponding fertile hybrids respectively, which showed significant cytoplasm effect. The yield of the male-sterile hybrid × high-oil hybrid was similar to that of the female parent, but its 1000-kernel weight was 7.3% lower than that of the female parent. Compared with the high-oil male parent, grain yield, 1000-kernel weight and kernel size of the male-sterile hybrid× high-oil hybrid were higher. Seed-filling rate, the days of seed-filling and IAA content in the male-sterile hybrid × high-oil hybrid showed average heterosis tending the female parent, which may be perhaps one of the reasons resulting in the average heterosis tending to the female parent on kernel oil content, yield, 1000-kernel weight and kernel size.

Analysis of a Partial Male-Sterile Mutant of Arabidopsis thaliana Isolated from a Low-Energy Argon Ion Beam Mutagenized Pool

A screen for Arabidopsis fertility mutants, mutagenized by low-energy argon ion beam, yielded two partial male-sterile mutants tc243-1 and tc243-2 which have similar phenotypes. tc243-2 was investigated in detail. The segregation ratio of the mutant phenotypes in the M2 pools suggested that mutation behaved as single Mendelian recessive mutations, tc243 showed a series of mutant phenotypes, among which partial male-sterile was its striking mutant characteristic. Phenotype analysis indicates that there are four factors leading to male sterility, a. Floral organs normally develop inside the closed bud, but the anther filaments do not elongate sufficiently to position the locules above the stigma at anthesis, b. The anther locules do not dehisce at the time of flower opening （although limited dehiscence occurs later）, c. Pollens of mutant plants develop into several types of pollens at the trinucleated stage. as determined by staining with DAPI （4＇,6-diamidino-2-phenylindole）. which shows a variable size. shape and number of nucleus. d. The viability of pollens is lower than that of the wild type on the germination test in vivo and vitro.

Development of Maweizhan cytoplasmic male-sterile line in rice(Oryza sativa L.)

A male sterile mutant plant was found from the rice field of the local rice variety which was cultivated for a long time in the west of Hubei Province. The plant has more vigorous tillering ability. Its plant height of 95 cm was a bit shorter than that of the normal ones. The plant type, the leaf shape and the color of leaf sheath and glume tip of this mutant were identieal to that of the normal plant whereas the color of arrowhead-shape anther was milky white. This mutant set no seed during self-pollination. When it was crossed with IR24. IR26, Minhui 63 or Xieqing-zaoxuian. the Ffertilities were normal. The fertility of this mutant could be restored by IR24, IR26 and Minhui 63 and maintained by Xieqing-zaoxian. Maxie A was developed in 1987 by the successive backcrossing of the mutant with Xieqing-zaoxian. The percentage of abortive pollen in Maxie A in uninucleate microspore to early binucleate microspore stage is

Relationship between rice heading sensitivity and male-sterile sensitivity to photoperiod in view of developmental genetics

We studied the relationship between the head-ing sensitivity and the male-sterile sensitivityin photoperiod-sensitive genie males-sterile rice(PGMSR)and conventional rice.Materialsused in this study were 7001S,a late maturingPGMS japonica strain derived from Nongken58S; Akihikari and Youmang-zaojing(YMZJ),two early maturing conventional Japonica rice;and CPSLO-17,a Wide compatible convention-al indica rice.The heading date and seed-set-ting rate of Fand Fof three cross combina-tions between PGMSR and conventional riceswere examined in phytotron which was adjust-ed at 25±1℃ with day-length of 14.5 h(LD)and 12 h(SD).The segregation ratio of fertile:sterile in Funder LD was in accordance

Effect of day length and temperature on the pollen fertility in photo(thermo)-sensitive genic male-sterile rice

The effect of day length and temperature on the pollen fertility of five photoperiod-sensitive genic male-sterile japonica rice lines (PGMSR) and three temperature-sensitive genic malesterile indica rice lines (TGMSR) were investigated in phytotron. The light source used for illumination was xenon lamp, and the light intensity which plant accepted on the leaf surface was 300—350μmol photons ms. The results indicated that pollens of PGMSR 7001S and E47S aborted completely whereas a little part of 31116S pollens appeared normal under long day photoperiod (LD,25℃,15h) (Table 1). High temperature (HT, 30℃, 12h) and lower temperature (LT,

Chromosome Location of the Male-sterility and Yellow Seedling Gene in Line 1066A of Foxtail Millet

Using foxtail millet (Setaria italica (L.) Beauv.) male-sterile line 1066A as female parent and Yugu 1 primary trisomic series (1 - 7) and tetrasomics 8, 9 as male parents, chromosome location of gene for male-sterility and yellow seedling in line 1066A was studied by primary trisomic analysis. The plants of F-1 generation of trisomics 2 - 9 were obtained by crossing with a great many plants of 1066A. F-1 generation of trisomics was similar to their male parent in morphologic characters, the color of their seedling was green, and pollen was partially fertile. The segregation ratio of fertility to sterility is 3:1 in F-2 generation of trisomics 2, 3, 4, 5, 7, 8 and 9; and 14:1 only in F-2 generation of trisomic 6 (chi(0.05)(2) = 0.012). The segregation ratio of green seedling to yellow seedling is 12:1 only in F-2 generation of trisomic 7 (chi(0.05)(2) = 0.31), but in other cases, this ratio is 3:1. The results indicated that the male-sterility gene was located on chromosome 6, and the gene for yellow seedling was monogenic recessive and located on chromosome 7. The rate of trisomics transmission by pollen was tested, trisomics 8 and 9 were the highest in rates of trisomics transmission and followed by trisomics 6 and 4.

青皮竹花形态结构与雌、雄配子的发育研究

[目的]揭示青皮竹自然条件下不同发育阶段花器官的形态及其雌、雄配子体的解剖结构特征。[方法]采用形态解剖及石蜡制片的方法对青皮竹花器官的各部分外观形态特征以及雌、雄配子体的发育过程进行观察与描述。[结果]青皮竹小穗为无限花序,下部的小花先发育,但因小穗基部具有潜伏芽,因此又具有有限花序的特征。每个小穗约有8~10朵小花,顶端小花不育,小穗基部含有2~3枚黄棕色苞片。每朵小花均有内、外稃各1枚,浆片3枚,雄蕊6枚,雌蕊1枚。雌雄异熟,异花授粉。子房呈花瓶状,下部光滑不具棱,上部有绒毛。子房1室,侧膜胎座,倒生胚珠,双珠被。短花柱长柱头,花柱具绒毛,三分枝羽状柱头。花药呈黄色,4药室。未成熟的花药的花药壁由外向内依次为表皮、药室内壁、中层和绒毡层。绒毡层为腺质型,花药成熟后绒毡层退化,仅剩表皮和纤维层。花粉成熟后2或3核花粉粒,花药壁纵裂散粉。[结论]青皮竹花器官形态与解剖结构发育正常,而雌、雄配子体发育过程中出现多种败育情况,可能是青皮竹结实率低的重要原因。

In Vitro Regeneration of Style-stigma-like Structure from Stamens of Crocus sativus

Style-stigma-like structures were regenerated from stamens of Crocus sativus L. The age of the stamen explant has an obvious effect on the induction rate. Auxin NAA. has larger effect on the induction of filament style-stigma-like structure. Auxin NAA of higher concentration can lead to higher induction rate. Temperature and light have different effects on the induction of style-stigma-like structure from anther's filament of C. sativus with exogenous hormones at different levels. Ultraviolet tests show that style-stigma-like structure from anther's filament of C. sativus contains crocin, safranal and picrocrocin, contents of which are obviously more than those contained in the style-stigma-like from style. Floral reversion was observed in the induction of style-stigma-like structure from petals, ovaries and styles.

阳春砂茉莉酸生物合成酶基因鉴定与时空表达分析

为探究阳春砂(Amomum villosum)花器中茉莉酸(JA)生物合成酶基因表达与雌雄蕊生长的关系,本研究利用cDNA末端快速扩增(RACE)技术克隆阳春砂JA生物合成酶基因的全长序列,并对各基因进行生物信息学分析、表达模式测定及各基因表达与阳春砂雌雄蕊生长的相关性分析,以探究阳春砂花器中JA生物合成酶基因表达与雌雄蕊生长的关系。结果表明,阳春砂中JA生物合成酶基因AvLOX、AvAOS、AvAOC、AvOPR3序列全长分别为2733、1798、930、1400 bp,分别包含2577、1485、744、1179 bp的开放阅读框(ORF),其编码蛋白分别含有858、494、247、392个氨基酸残基。4个JA生物合成酶基因的表达随阳春砂雄蕊的发育进程逐渐增加,但在雌蕊中的表达则呈现多样性。在雌蕊中,AvLOX、AvAOS基因在开花后1天表达最高,AvAOC在标记后第9天表达最高,AvOPR3基因在标记后第6天表达最高。除AvAOS基因在小花在标记后第3天以及AvOPR3基因在小花标记后第6天外,4个JA生物合成酶基因在雄蕊中的表达在各发育阶段显著高于同时期在雌蕊中的表达。与对照组相比,在喷施茉莉酸甲酯(MeJA)后,4个JA生物合成酶基因在雄蕊中的表达模式,以及AvLOX和AvOPR3基因在雌蕊中的表达模式没有改变,但AvAOS和AvAOC基因在雌蕊中的表达模式有变化。在对照组和MeJA处理组中,4个JA生物合成酶基因的表达与阳春砂小花花丝和花柱的长度有极显著的相关性。本研究结果为进一步探究JA与阳春砂花器官生长发育的关系奠定了基础。

金鱼草KNOX基因家族鉴定及调控其雄蕊瓣化的候选基因挖掘

【目的】KNOX(KNOTTED1-like homeobox)转录因子家族在植物生长发育及花器官发育中发挥重要作用。文章旨在鉴定并分析金鱼草(Antirrhinum majus)KNOX转录因子,挖掘出调控金鱼草雄蕊瓣化的关键候选基因。【方法】采用生物信息学方法,在金鱼草全基因组水平鉴定AmKNOX基因,并对其基因结构、蛋白理化性质、亚细胞定位、系统进化关系、染色体定位、启动子顺式作用元件及转录因子结合位点等进行分析,并利用金鱼草雄蕊瓣化和非瓣化材料进行RNA-seq分析和qRT-PCR验证,挖掘出候选基因。【结果】从金鱼草中共鉴定出11个AmKNOX基因,都具有KNOXⅠ、KNOXⅡ、ELK和HOX 4个相对保守的区域,分为ClassⅠ(AmKNOX1、AmKNOX2、AmKNOX3、AmKNOX9和AmKNOX11)和ClassⅡ(AmKNOX5、AmKNOX4、AmKNOX7、AmKNOX10、AmKNOX6和AmKNOX8)2类。AmKNOXs蛋白包含282~406个氨基酸,均定位于细胞核中。启动子顺式作用元件分析结果显示,AmKNOXs家族成员可参与植物生长、激素和非生物胁迫响应,且AmKNOXs存在大量与植物生长发育、器官分化和逆境生理调节相关的转录因子结合位点。RNA-seq和qRT-PCR分析表明AmKNOX家族基因在金鱼草正常雄蕊和瓣化雄蕊中显著差异表达。【结论】本研究共鉴定出11个AmKNOX成员,最终挖掘出5个正向(AmKNOX5、AmKNOX10、AmKNOX6、AmKNOX4和AmKNOX9)以及1个负向(AmKNOX11)调控雄蕊瓣化的AmKNOX候选基因。其中AmKNOX5基因在瓣化雄蕊中的表达量比正常雄蕊中高2703%,推测其功能非常重要,该研究为后期深入解析金鱼草花型发育分子机制和遗传改良奠定了基础。

13个紫薇品种花粉形态及花粉活力分析

【目的】研究紫薇品种间的花粉形态特征及花粉活力差异,为后续紫薇品种杂交育种工作提供理论参考。【方法】通过扫描电子显微镜对13个紫薇品种的雄蕊群花粉粒表面形态特征进行观察研究,每个品种随机选取10粒花粉进行统计分析,同时利用固体培养基对13个紫薇品种的花粉活力进行测定。【结果】13个紫薇品种长短雄蕊花粉粒均呈长球形,有3条萌发沟,裂至接近两极,萌发沟间未连接,在极面观花粉粒呈钝三角形,均属于N3P4C5型花粉。紫薇品种间花粉粒外壁纹饰、极轴长、赤道轴长、萌发沟特征及花粉粒体积大小均差异显著,其中花粉大小为538.91~1402.40μm^(2),极轴长为30.51~46.31μm,赤道轴长为17.35~31.49μm,萌发沟长为18.38~34.36μm,萌发沟脊宽为5.72~11.34μm。花粉外壁主要包括孔穴状、脑皱状及皱波状3种纹饰,13个试验品种长雄蕊花粉粒相比于短雄蕊花粉粒,其花粉粒表面更为光滑饱满。花粉活力测定结果以‘紫精灵’紫薇花粉活力最强,花粉活力为93.94%,其中‘湘韵’紫薇为不育品种,其不育类型表现为雄性不育,花粉不萌发。【结论】紫薇不同品种的花粉粒形态特征和花粉粒表面纹饰可以作为紫薇品种分类鉴定的参考指标之一,本试验中的13个紫薇品种除不育品种‘湘韵’紫薇外,其他试验品种表现出较高的花粉活力,均可作为紫薇品种杂交育种工作材料。

RcAGL61基因调控雄蕊和花瓣之间转变影响月季花瓣数量

[目的]为探究月季重瓣性状的调控机制,研究克隆了前期筛选到的1个与花发育相关的AG同源基因RcAGL61,并对其功能进行分析。[方法]用荧光定量对该基因在‘窄叶藤本月季花’ב月月粉’杂交群体中重瓣株系和单瓣株系花芽5个发育时期的表达模式进行分析,以重瓣株系和单瓣株系为材料,克隆RcAGL61,并进行生物信息学分析、亚细胞定位及VIGS实验。[结果](1)该基因表达水平在单瓣株系的5个发育时期均显著高于重瓣株系,在单瓣株系花发育的S4-S5期比S1-S3期表达量明显升高。(2)RcAGL61编码区序列在单瓣株系和重瓣株系中一致,长度为495 bp,与RcAG基因序列相似度为30.75%,编码164个氨基酸,含有1个MADS-box保守结构域,属于MADS-Box基因家族。(3)RcAGL61蛋白定位于烟草表皮细胞的细胞核。(4)沉默该基因后,瓣化雄蕊数量增加,雄蕊数量减少,花瓣数量增加,萼片数量和雌蕊数量无显著变化。[结论]RcAGL61参与调控雄蕊原基和花瓣原基间的转变,影响月季的花瓣数量。

早春不稳定传粉环境中新疆郁金香混合交配系统中的自交策略

[目的]在不确定传粉环境中,两性花植物常常具有潜在自交能力,鉴于自交的交配代价,进行不同环境下自交策略研究,对深入理解植物交配系统的演化具有重要意义。[方法]以早春短命植物新疆郁金香为研究对象,通过野外观测及人工控制试验对自然居群的开花习性、传粉者类群、散粉动态、自花粉传递模式和交配系统等进行研究,以探讨早春不稳定传粉环境中植物的自交策略。[结果](1)新疆郁金香自然种群4月上旬或中旬开花,单花期5~6 d,白天开放晚上闭合,花粉的释放从外轮开始,由下到上呈拉链式次序呈现。(2)传粉者主要为蜂类和食蚜蝇,访花频率普遍较低,且年份间存在较大差异,但结实率普遍较高。(3)控制授粉试验表明,居群为异交为主,部分自交亲和的混合性交配系统。傍晚花闭合时雄蕊的自主运动促进了柱头的自花授粉,这一传粉模式促进了竞自交的发生,但大量自花粉的落置发生在开花后的第4天,占自花粉总落置量的50.22%,为一种延迟自交机制。[结论]在传粉受限的情况下,新疆郁金香的竞自交和延迟自交促进柱头的花粉落置,这种集异交、竞自交和延迟自交为一体的交配策略灵活地应对了早春不稳定的传粉环境,是对早春低温度条件下不确定传粉服务的一种适应,也是早春短命植物的一种繁殖保证对策。