Male Sterile Lines of Zinnia elegans and Their Cytological Observations

In order to find out a new pathway for utilizing heterosis of Zinnia elegans and accelerate breeding process, the mechanism of anther development of a male sterile line was explored. Backcross, sibmating, selling of fertile plants and testcross with inbred lines were analyzed and identified in the field, and cytology was observed. Recessive nucleus male sterile line AH209AB capable of being a maintainer was obtained by successive backcrosses with male sterile plants and fertile F1 plants as male parents. Cytological and anatomical studies indicated that： （1） The wall of normal anther was constituted of four layers of cells such as epidermis, powder chamber wall, middle level and tapetum cells. The process in meiosis of pollen mother cell in Zinnia elegans was normal and cytoplasm divided simultanously. Mature pollen grain was tricellular type. （2） The petal of male sterile plant degraded as a thread-like structure, the stamens were villiform in appearance and no pollens were formed. The result showed that the anther of male sterile plant no longer proceed to differentiate spore mother cell and the pollen sac after the formation of the tissue of sporogenous cells, there was no evident boundary between tapetum cell, middle lamella and inner wall of PMC, tapetal cells did not develop from the very beginning. So the abortion type was completely structural male sterility. The male sterile line belongs to non-sporange male sterile type and is of great use in F1 seeds production.     

Development of Japonica Male Sterile Lines Integrating Cytoplasmic Male Sterility and Photosensitive Genic Male Sterility

Acknowledgement It has been previously established that the BT type of cytoplasmic male sterility （CMS） is induced by high temperatures, while photosensitive genic male sterility （PGMS） seed sets by low temperatures induce. In the current study, we have bred photosensitive cytoplasmic male sterility （PCMS） lines （2308SA and 2310SA） by crossing the CMS line with the PGMS japonica line with maintainer genes. The sterility of PCMS japonica was consequently controlled by two groups of male sterile genes resulting from the integration of PGMS and CMS genes. The results on plant fertility, at different sowing times, were as follows： （a） Under conditions of natural long-day photoperiod and at temperatures above 35~C, the PGMS gene regulated PCMS japonica sterility - the higher the temperature, the lower the pollen fertility. However, bagged seed sets of PCMS japonica, not exposed to high temperatures, induced the CMS seed set. （b） Exposure to long-day photoperiod and temperature conditions between 35℃ and the critical sterility inducing temperature of PGMS resulted in both PGMS and CMS gene controlled sterility of PCMS japonica, which exhibited stable characteristics. （c） When exposed to critical sterility inducing temperatures or short-day photoperiod and daily high temperatures below 32℃, the BT type of the CMS gene regulated PCMS sterility. Under these conditions, the PGMS gene rendered male sterility insusceptible to occasional cool summer days when this PCMS line, adopted for hybrid seed production, develops into panicle differentiation stage. The present study also investigated the fertility restoration, seed production and combining ability of PCMS japonica so as to optimize its use.     

Plant Male Sterility Induced by Anti-Gene CYP86MFin Brassica oleracea var. Italica

An anti-gene CYP86MF was introduced into hypocotyls of broccoli （Brassica oleracea L.var. italica Plenck） with Agrobacterium tumefaciens, and the transgenic plants were obtained by kanamycin selection. The results of PCR, Southern blot and Northern blot indicated that the anti-CYP86MF has been integrated into chromosome of the transgenic plant. And also, plants with hypogenetic stamina or ungerminated pollen were observed. The transgenic male sterility plant could fructify via artificial pollination with normal pollen. Thus it was proved that the pistil of male sterility plant was normally developed, and the sterility originated from anti-CYP86MF.     

Abortive Process of a Novel Rapeseed Cytoplasmic Male Sterility Line Derived from Somatic Hybrids Between Brassica napus and Sinapis alba

Somatic hybridization is performed to obtain significant cytoplasmic male sterility （CMS） lines, whose CMS genes are derived either from the transfer of sterile genes from the mitochondrial genome of donor parent to the counterpart of receptor or production of new sterile genes caused by mitochondrial genome recombination of the biparent during protoplast fusion. In this study, a novel male sterile line, SaNa-IA, was obtained from the somatic hybridization between Brassica napus and Sinapis alba. The normal anther development of the maintainer line, SaNa-IB, and the abortive process of SaNa-IA were described through phenotypic observations and microtome sections. The floral organ of the sterile line SaNa-IA was sterile with a shortened filament and deflated anther. No detectable pollen grains were found on the surface of the sterile anthers. Semi-thin sections indicated that SaNa-IA aborted in the pollen mother cell （PMC） stage when vacuolization of the tapetum and PMCs began. The tapetum radically elongated and became highly vacuolated, occupying the entire locule together with the vacuolated microspores. Therefore, SaNa-IA is different from other CMS lines, such as ogu CMS, pol CMS and nap CMS as shown by the abortive process of the anther.     

Cytoplasmic Male Sterility in Maize

14 isoplasmic and allonuclear cytoplasmic male sterile lines were used as female parents, 8 tester lines as male parents, 101 F1 progenies were obtained. Fertility restoration response of 101 F1 progenies were investigated through field observation and pollen stainability examination under microscope. 14 isoplasmic and allonuclear cytoplasmic male sterile lines were developed by repeated backcross with recurrent male parent lines for more than 8 generations. The result shows: tester line Zifeng1 not only restored the isoplasmic and allonuclear sterile lines of group C backcrossed with Mo17, Yu30 and Heer, but also completely restored the isoplasmic and allonuclear cytoplasm male sterile lines of group T backcrossed with Mo17, HZS , 1792 ,292 and Yu30. Therefore, nuclear background limits the use of Zifeng1 as a tester for identification of cytoplasmic male sterility. Furthermore RFLPs of mitochondrial DNA of 6 isonuclear and alloplasmic cytoplasmic male sterile lines were analyzed with Bam H Ⅰ and Hind Ⅲ restriction endonuclease and mitochondrial DNA probes pBcmH3 and Cox Ⅱ. The same RFLPs were found within sterile cytoplasm of group C, including C,Chuan G, Lei 2 and Lei 3, but a different RFLP pattern was observed among sterile cytoplasm of group S, C,T and the normal cytoplasm. This result suggested that the RFLP markers tightly linked to sterile mitochondrial genes of different groups could be applied in the identifcation of cytoplasmic male sterility.     

Expression of an Antisense BcMF3 Affects Microsporogenesis and Pollen Tube Growth in Arabidopsis

In an effort to provide some information relevant to the molecular mechanism of genic male sterility in plants, BcMF3 gene that encodes a pectin methylesterase was isolated from the fertile B line of Chinese cabbage-pak-choi （Brassica rapa ssp. chinensis, syn. B. campestris ssp. chinensis）. In the present paper, a 455-bp antisense cDNA fragment of BcMF3 was introduced to binary vector pB1121, and then was mobilized into Agrobacterium tumefaciens strain LBA4404. The A. tumefaciens harboring the BcMF3 antisense fragment was transformed to Arabidopsis thaliana by floral dip. Scanning electronic microscopy examination demonstrated that 47.8% of BcMF3 antisense pollen grains exhibited abnormal shape, which might lead to decreased germination of pollens, suggesting that the product of BcMF3 gene plays an important role during microsporogenesis. The evidence on burst of 45.7% of BcMF3 antisense pollen tubes in vitro and a majority of BcMF3 antisense pollens restricted within the stigmatic tissue revealed that BcMF3 is involved in aiding the growth of pollen tubes. The results suggest that BcMF3 acts at both stages of microsporogensis and pollen tube growth.     

Detection of Distorted Segregation in Genotype of Pollen Calli Derived from Hybrid F1 of Cultivated Rice （Oryza sativa L.） Using SSR Markers

S-a, S-b and S-c are three loci for F1 pollen sterility in cultivated rice （Oryza sativa L.）. Taichung 65 （T65） is all Sj/Sj at these three loci, while its F1 pollen sterile near-isogenic lines, TISL2 （S-b）, TISL4 （S-a） and TISL5 （S-c） is Sj/Sj according to their respective sterility locus. Using SSR molecular marker to detect the segregation of the allele Si and Sj in pollen calli population induced from different hybrid F1, which have different pollen sterility locus, showed that the segregation of allele Si and Sj was distorted. The distorted direction of pollen calli population in vitro was not the same as F2 population in vivo. The quantities of pollen callus carrying Sj were much more than that of carrying Siat S-a and S-c locus, the ratio of Si and Sj were 1：4.81 and 1：1.96 respectively. But the opposite tendency was observed at S-b locus, the ratio of Si and Sj being 1：0.35. At the same time, all these results were undisturbed by either culture medium or culture period.     

Development of marker Ms2 gene with a blue seed in durum and common wheat

In order to marker dominant nuclear gene Ms2 with a blue grain, a 4E disomic addition line ＇xiaoyanlanli＇（2n=44, AABBDD＋4EII） as the male parent to pollinate with male-sterile plants of durum wheat, controlled by a dominant nuclear gene Ms2, and a durum wheat line 89-2343 with Ms2 and blue seed marker on the same addition chromosome was developed. The genotype 89-2343 was crossed and backcrossed with a common wheat genotype 7739-3 to produce male fertile plants with blue seeds （MFP-BS）. To combine the blue seed marker, dwarf male-sterile plants carrying RhtlO and Ms2 were fertilized by pollen from selected MFP-BS. At last, the combination of blue seed marker, Ms2 and RhtlO was successfully produced. The segregation ratio of male sterility, seed color as well as chromosome configurations of the combinations suggested that the blue seed marker, Ms2 and RhtlO were located on the same chromosome. Cytological analysis indicated that the male sterile wheat line with a blue seed marker was 43 in chromosome number, with an additional chromosome. The transmission rate for blue seed male-sterile plants was 22.1% in common. In addition, the potential value for blue marker sterile lines in wheat breeding and hybrid production is discussed.     

Application of Molecular Markers Linking to Cytoplasmic Male Sterile Loci to Assist Maintainer Line Selection and Their Selection Efficiency in Welsh Onion （Allium fistulosum L.）

Cytoplasmic male sterility exists widely in most natural populations of welsh onion （Alliumfistulosum L.）, which makes it possible to breed out many male sterile lines for heterosis utilization. Unfortunately, the breeding of cytoplasmic male sterility in welsh onion has a little progress due to the limitation of its biological characteristic and traditional selection approach. To study the feasibility and the efficiency of utilizing marker assisted selection for male sterile lines in welsh onion, one SCAR marker, SCS13, and one RAPD marker, S2002400, which could distinguish between N and S cytoplasm in several welsh onion cultivars, were identified. The two markers were then confirmed by Southern blotting, and used to screen the N or S cytoplasm of individual plants in seven welsh onion cultivars in this study. Male sterile and fertile plants were evaluated by aceto-carmine dying. The frequency of N-cytoplasmic plants and maintainer genotype was calculated in the seven open populations of welsh onion. The minimum number of plants needed to identify a maintainer was evaluated to be 95% reliable. Results showed that 20 to 80% decrease of crosses and self-crosses for identifying a maintainer genotype could be achieved by the marker-assisted selection compared with traditional selection method. It was proved that the molecular markers could precisely identify cytoplasmic types individually, performed by one generation of cross and two generations of testcrosses and self-crosses. Finally, several maintainer genotype plants were selected with the help of the two markers in the seven cultivars. The screened markers could assist and accelerate sterile and maintainer lines selection with less labor and cost.     

Cytological Observation of Microsporogenesis in Male-Sterile Lines of Chinese Pink （ Dianthus chinensis L.）

This study addressed the differences in microsporogenesis between male sterile and fertile lines of Chinese pink. The microsporogenesis processes of male sterile and fertile lines were histologically examined in squashed pollen grains and in paraffin embedded sections. A stable male-sterile line （H-37B） was obtained following six generations of inbreeding in a self-fertile line, followed by two generations of backcrossing. In the corresponding fertile line, development of the mature pollen grains was followed through the initiation of the sporogenous cell, microsporocyte formation, and the tetrad developmental period. In the male-sterile line, abortion of the developing pollen grains was observed to take place at various stages, namely, sporogenous cell growth, mother cell meiosis, and tetrad transformation to the uninuclear state. The pollen grains of the fertile line were spheroid, turgid, and viable. By contrast, the male-sterile line produced pollen that was irregular in shape, empty, and nonviable. The abortion of the microspore in the male-sterile line appeared to relate to abnormal growth of the tapetum layer.     

宁夏枸杞雄性不育育性标准研究

1材料与方法1．1材料材料为宁夏枸杞“YX-1”雄性不育植株和“宁杞1号”植株的新鲜花蕾,均采于银川市西夏区育新枸杞种业有限公司枸杞种植园新区。     

宁夏枸杞雄性不育育性标准研究

[目的]研究宁夏枸杞雄性不育育性标准,为枸杞雄性不育杂交育种工作奠定基础。[方法]采用田间调查法和室内涂片及石腊切片法,对宁夏枸杞“YX-1”的生殖器官植物学特征、花粉囊中花粉粒形成的多少进行观察研究。[结果]宁夏枸杞“YX-1”主要为不完全不育株,并进一步将枸杞雄性不育株育性划分为全不育型、不育I型、不育Ⅱ型3种类型。[结论]初步提出了宁夏枸杞雄性不育育性标准。     

枸杞雄性不育性与游离脯氨酸含量的关系

[目的]揭示枸杞雄性不育败育的生理生化机制。[方法]通过分析比较枸杞雄性不育株和可育株叶片及花蕾中游离脯氨酸的含量研究枸杞雄性不育性与游离脯氨酸含量的关系。[结果]在减数分裂期和花粉成熟期,雄性不育株YX-1的叶片游离脯氨酸含量高于可育株宁杞1号。叶片游离脯氨酸含量在春梢生长期最高,在展叶期最低。在生殖生长阶段,宁杞1号的叶片游离脯氨酸含量逐渐降低,YX-1的叶片游离脯氨酸含量逐渐升高。随着花蕾的发育,YX-1的花蕾脯氨酸含量逐渐降低,宁杞1号的花蕾脯氨酸含量逐渐升高。在减数分裂时期和花粉成熟期,YX-1的花蕾游离脯氨酸含量明显低于宁杞1号。[结论]不育株叶片游离脯氨酸含量高于可育株,花蕾游离脯氨酸含量低于可育株,可能是导致雄性不育的原因。     

基于nrDNA ITS序列对枸杞雄性不育材料的鉴别

对7份常规枸杞种质和1份枸杞雄性不育材料的DNA中nrDNA ITS(核糖体DNA基因内转录间隔区)序列进行分析,从分子水平对枸杞雄性不育材料作出鉴定.采用改进CTAB法提取枸杞叶片DNA,利用合成的特异引物对其DNA中nrDNA ITS区进行扩增、克隆,对目的片段测序分析.结果显示首次测序得到了枸杞雄性不育材料和其他7份常规枸杞种质的nrDNA ITS区碱基序列,整个ITS序列长度为559～633 bp,平均为612 bp,共有160个变异位点,占25.3%;保守位点473,占74.7%;67个转换位点和31个颠换位点.表明基于nrDNA ITS区序列分析可作为鉴定枸杞雄性不育材料的一种新的鉴别方法.     

枸杞雄性不育株花药败育的显微结构观察

选用枸杞"YX-1"雄性不育株不同发育时期的花蕾为试材,以当地主栽品种宁杞1号为对照,利用石腊制片技术对其花蕾不同发育时期的细胞显微结构进行比较研究.结果表明:在造孢细胞时期,雄不育植株造孢细胞有解体现象;在花粉母细胞时期,雄不育植株有的表现为花药大小分布不均,表现为绒毡层细胞内含物融合形成周原质团;在四分体期,雄不育植株花药壁有的表现为畸形,扭曲成瘤状突起,有的表现为药隔和花粉囊壁分离,四分体形成数量少;绒毡层发育异常,雄不育株绒毡层细胞内含物融合形成周原质团或细胞径向伸长形成周原质团并侵占药室,导致小孢子败育或形成数量极少的小孢子,最终形成完全不育型和不育I型 .枸杞雄不育植株的花粉败育时期可发生在造孢细胞期到四分体期.     

不育枸杞花药营养物质代谢与花粉败育的关系

[目的]研究不育枸杞花药营养物质代谢与花粉败育的关系,为拘杞不育系花粉败育机制研究提供理论依据。[方法]运用半薄切片和细胞化学染色技术,对枸杞不育系和可育系花药营养物质积累和分布状况进行观察和比较分析。[结果]与可育系相比,不育系花药减数分裂后,淀粉粒在药隔薄壁组织中骤减,表皮和药室内壁中的淀粉粒也大幅减少,绒毡层没有脂质积累;绒毡层和四分孢子先后发生液泡化,进入解体过程。[结论]药隔维管束多糖供应下降,导致绒毡层细胞糖脂转化机制发生紊乱,由此引发了绒毡层提前进入细胞程序性死亡过程,四分孢子因营养匮乏,最终解体。     

三种核不育水稻材料花粉育性基因遗传规律的研究

本文通过对花粉不育型无融合水稻SAR—1、籼型温敏核不育水稻W6154S、川农核不育水稻(H_2S)等花粉育性遗传规律的研究,结果表明:(1)SAR—1的花粉育性受细胞核内一对主效隐性基因控制,并受到一些微效修饰基因的影响,SAR—1及其杂交后代中出现的不育株套袋结实率较高;(2)W6154S花粉育性受细胞核内两对主效隐性基因控制和一些微效修饰基因作用,受环境条件(主要是温度)的影响较大,W6154S本身及其杂交后代中的不育株套袋自交结实率较高;(3)H_2S的花粉育性受细胞核内一对隐性基因支配,H_2S本身及杂交后代中的不育株均属无花粉型,受环境影响小,套袋不结实。     

萝卜异质型不育系034A和杂交萝卜“泸萝6号”的选育

通过萝卜远缘杂交创建不育源,再经过回交转育而选育出异源胞质不育系034A。034A属无花粉型,不育度100％,不育株率98．25％,育性稳定。配制的组合034A／062杂种优势强,每公顷产量44．37t,比对照春不老萝卜增产13．14％。在品比和多点试验中,产量、品质、抗病性、抗逆性均超过对照,2004年通过四川省农作物品种审定委员会审定,审定名为“泸萝6号”。     

一个玉米细胞质雄性不育系的鉴定及遗传分析

【目的】阐明新育成的雄性不育系农系928cms-Q1261的胞质类型、败育时期和遗传机制,为其育种应用提供依据。【方法】将不育系在不同年份、不同地点种植,鉴定育性表现,通过测交、姊妹交、反交对不育性的遗传进行分析,利用特异引物进行PCR扩增鉴定胞质类型,通过石蜡切片法在光学显微镜下观察小孢子发育过程。【结果】农系928cms-Q1261雄穗无花药外露,花粉败育彻底,不育性表现稳定;质不育基因来自自交系Q1261,为S型;核不育基因来自农系928,由1对隐性基因控制;小孢子从单核晚期开始自溶,成熟期完全降解;自交系郑58能保持其不育性。【结论】农系928cms-Q1261属于S型不育胞质,是一种无花粉型的细胞质雄性不育系,其恢复系广泛。     

无花粉型水稻温敏核不育系籼S不育特性遗传的初步研究

【目的】籼S是由常规稻籼黄占自然突变株选育而成的新型无花粉温敏核不育水稻,对籼S的不育特性遗传进行初步分析,为该品种的进一步研究和生产利用奠定基础。【方法】应用经典遗传学分析方法,将籼S与多个常规稻进行杂交,调查杂交后代F₁、正反交F₁、F₂、BCF₁育性,并分析F₁不育株禾蔸的不育特性。【结果】籼S在广州(23°08′N)自然条件下,5月上旬至10月下旬为稳定不育期,不育期较培矮64S长近2个月;籼S的温敏核不育性可以被不同类型常规稻品种恢复,且恢复度较高,说明控制其不育性的基因为隐性遗传;各正、反交花粉可育率及套袋自交结实率差异均不显著,表明籼S的不育性遗传与细胞质无关;绝大多数F₂代群体不育株数与可育株数比值符合1∶3,育性不仅呈非连续分布,且可育株、不育株基本表现为极端分离,13个BCF₁代群体不育株数与可育株数比值均符合1∶1,表明籼S的不育性遗传受1对主效基因控制;F₂不育株禾蔸育性转换与籼S相似,最终均表现为无花粉型败育,且均具有温敏性。【结论】籼S不育性属于隐性遗传,由核基因控制,其不育性基本符合1对主效基因的遗传模式,且其无花粉型败育方式及温敏性能在杂交后代中遗传。