Genetics of Male Sterility in Gynodioecious Plantago Coronopus. II. Nuclear Genetic Variation

Inheritance of male sterility was studied in the gynodioecious species Plantago coronopus using five plants and their descendants from an area of ~50 m(2) from each of four locations. In each location, crosses between these five plants yielded the entire array of possible sex phenotypes. Both nuclear and cytoplasmic genes were involved. Emphasis is placed on the nuclear (restorer) genetics of two cytoplasmic types. For both types, multiple interacting nuclear genes were demonstrated. These genes carried either dominant or recessive restorer alleles. The exact number of genes involved could not be determined, because different genetic models could be proposed for each location and no common genetic solution could be given. At least five genes, three with dominant and two with recessive restorer allele action, were involved with both cytoplasmic types. Segregation patterns of partially male sterile plants suggested that they are due to incomplete dominance at restorer loci. Restorer genes interact in different ways. In most instances models with independent restorer gene action were sufficient to explain the crossing results. However, for one case we propose a model with epistatic restorer gene action. There was a consistent difference in the segregation of male sterility between plants from the two cytoplasmic types. Hermaphrodites of cytoplasmic type 2 hardly segregated male steriles, in contrast to plants with cytoplasmic type 1.     

A Cryptic Cytoplasmic Male Sterility Unveils a Possible Gynodioecious Past for Arabidopsis thaliana

Gynodioecy, the coexistence of hermaphrodites and females (i.e. male-sterile plants) in natural plant populations, most often results from polymorphism at genetic loci involved in a particular interaction between the nuclear and cytoplasmic genetic compartments (cytonuclear epistasis): cytoplasmic male sterility (CMS). Although CMS clearly contributes to the coevolution of involved nuclear loci and cytoplasmic genomes in gynodioecious species, the occurrence of CMS genetic factors in the absence of sexual polymorphism (cryptic CMS) is not easily detected and rarely taken in consideration. We found cryptic CMS in the model plant Arabidopsis thaliana after crossing distantly related accessions, Sha and Mr-0. Male sterility resulted from an interaction between the Sha cytoplasm and two Mr-0 genomic regions located on chromosome 1 and chromosome 3. Additional accessions with either nuclear sterility maintainers or sterilizing cytoplasms were identified from crosses with either Sha or Mr-0. By comparing two very closely related cytoplasms with different male-sterility inducing abilities, we identified a novel mitochondrial ORF, named orf117Sha, that is most likely the sterilizing factor of the Sha cytoplasm. The presence of orf117Sha was investigated in worldwide natural accessions. It was found mainly associated with a single chlorotype in accessions belonging to a clade predominantly originating from Central Asia. More than one-third of accessions from this clade carried orf117Sha, indicating that the sterilizing-inducing cytoplasm had spread in this lineage. We also report the coexistence of the sterilizing cytoplasm with a non-sterilizing cytoplasm at a small, local scale in a natural population; in addition a correlation between cytotype and nuclear haplotype was detected in this population. Our results suggest that this CMS system induced sexual polymorphism in A. thaliana populations, at the time when the species was mainly outcrossing.     

植物细胞质雄性不育

近年来国内外对植物细胞质雄性不育（cytoplasmic male sterility,CMS）在细胞学、生理生化及分子遗传学等方面的研究又取得了新的进展。特别是对育性恢复基因的定位、克隆的研究已取得一定突破,发现编码含保守PPR（pentatricopeptide repeat）模体蛋白的基因在多种植物中与育性恢复密切相关。     

向日葵CMS育性恢复的研究

向日葵细胞质雄性不育（Ｃｙｔｏｐｌａｓｍｉｃｍａｌｅｓｔｅｒｉｌｉｔｙ,ＣＭＳ）育性恢复的机理是非常复杂的。运用遗传学和分子生物学方法,分析了具代表性的４种不同细胞质类型的ＣＭＳ育性被恢复的频率和２０种向日葵自交系对１９种ＣＭＳ的恢复能力及个别ＣＭＳ植株自发恢复的原因。实验结果表明,４种ＣＭＳ品系育性被恢复的频率分别为５８．８％．５６．３％．１１．８％和０％．２０种自交系的恢复力为５．９－７５．０％。部分ＣＭＳ品系和大多数自交系含有恢复基因,恢复基因的数量及类型决定了ＣＭＳ品系被恢复的程度及自交系的恢复能力。同时,提出并证实了线粒体不育基因变异是导致ＡＲＧ１ＣＭＳ植株自发恢复育性的主要原因。     

Cytoplasmic Male Sterility in Barley. Xi. the msm2 Cytoplasm

A new cytoplasmic male sterility in barley (Hordeum vulgare s.l.) is described and designated as msm2. The cytoplasm was derived from a selection of the wild progenitor of barley (H. vulgare ssp. spontaneum). This selection, 79BS14-3, originates from the Southern Coastal Plain of Israel. The selection 79BS14-3 has a normal spike fertility in Finland. When 79BS14-3 was crossed by cv. Adorra, the F₁ displayed partial male fertility and progeny of recurrent backcrosses with cv. Adorra were completely male sterile. Evidently 79BS14-3 is a carrier of a recessive or semidominant restorer gene of fertility. The dominant restorer gene Rfm1a for another cytoplasmic male sterility, msm1, is also effective in msm2 cytoplasm. The different partial fertility restoration properties of msm2 and msm1 cause these cytoplasms to be regarded as being distinct. Seventy spontaneum accessions from Israel have been studied for their capacity to produce F₁ restoration of male fertility both in msm1 and in msm2 cytoplasms with a cv. Adorra-like seed parent (nuclear gene) background. The msm2 cytoplasm shows partial restoration more commonly than msm1 in these F₁ combinations. The mean restoration percentage per accession for msm2 is 28, and for msm1 4. Most of the F₁ seed set differences of the two cytoplasms are statistically significant. When estimated with partially restored F₁ combinations, msm2 cytoplasm appeared to be about 50 times more sensitive to the male fertility-promoting genes present in the spontaneum accessions. The spontaneum sample from Central and Western Negev, which has been found to be devoid of restoration ability in msm1 cytoplasm, had only low partial restoration ability in msm2 (mean 0.3%). The female fertility of msm2 appears normal. The new msm2 cytoplasm could be useful in producing hybrid barley.     

Plant Mitochondrial Genome Evolution and Cytoplasmic Male Sterility

Mitochondria are responsible for providing energy currency to life processes in the molecular form of ATP and are therefore typically referred to as the power factories of cells. Plant mitochondria are also relevant to the common phenomenon of cytoplasmic male sterility, which is agronomically important in various crop species. Cytoplasmic male sterility (CMS) is a complex trait that may be influenced by patterns of mitochondrial genome evolution, and by intergenomic gene transfer among the organellar and nuclear compartments of plant cells. Here, we review patterns and processes that shape plant mitochondrial genomes, some relevant interactions between organelles, and the general features shared by the majority of cytoplasmic male-sterile genes in plants to further the goal of understanding CMS.     

Microsporogenesis and the Mechanism of Cytoplasmic Male Sterility in Maize

Examination of the structural changes occurring during microsporogenesisin cms-T, -C and -S Zea mays L. with different nuclear backgroundsrevealed considerable variations in the stages at which abortionof the sporocytes occurred within each cytoplasmic genotype.This variation was not associated with the nuclear background.Significantly, we found that the mitochondria in cms-T plantsdid not always follow the pattern of degeneration describedpreviously. We conclude that these observations are not consistentwith a proposed mechanism of cytoplasmic male sterility involvingthe direct, antagonistic action of an anther produced substanceon an altered mitochondrion or plastid, that is functionallynormal in the rest of the plant. The value of microscopic studiesin detecting variation in apparently uniform material is emphasised,though it is recognized that other methods will be requiredto elucidate the mechanism of male sterility. male sterility, mitochondria, cytoplasmic inhertance, microsporogenesis, Zeamays L., maize, corn     

Mitochondrial Respiration Associated with Cytoplasmic Male Sterility in Pearl Millet

Respiratory activities in vegetative tissues and the isolated mitochondria of etiolated seedlings and reproductive tissues were studied in two cytoplasmic male sterile (CMS) lines having the same A, cytoplasm with different nuclear backgrounds of pearl millet along with their maintainer, restorer and restored lines. In addition, the assays of cytochrome c oxidase and succinate dehydrogenase were performed in isolated mitochondria. Cyanide-sensitive, cyanide-insensitive and total respirations in vegetative tissues and isolated mitochondria were lower in both the CMS lines than their respective maintainers, restorers and restored hybrids. Except in CMS lines, uptake of 0₂ during anther development increased from premeiotic to postmeiotic stage in all the lines. Consumption of 0₂,however, declined from meiotic to postmeiotic stage in the anthers of CMS lines. Pure mitochondrial preparations were obtained which were 92-94% intact. Enzymes, cytochrome c oxidase (complex IV) and succinate dehydrogenase (complex II) showed lower activities in both the CMS lines than their respective maintainer, restorer and restored hybrids. The CMS lines also displayed lower levels of nuclear encoded enzymes, viz., alternative oxidase and succinate dehydrogenase.     

细胞融合与植物细胞质雄性不育性状改良

原生质体融合技术不仅可以实现核基因组的重组,而且可以实现胞质基因组的重组,为转移由线粒体DNA或叶绿体DNA控制的性状提供了一条捷径。本文综述了获得胞质杂种的方法及其原理,细胞融合在胞质转移及创造新的细胞质雄性不育(CMS)资源上的研究进展及其应用情况,以及CMS在有性后代中的遗传规律,探讨了此育种途径的优势及其在木本果树无籽育种上的应用。     

水稻线粒体基因组翻译产物与细胞质雄性不育性

通过线粒体离体翻译产物的电泳和放射性自显影分析,发现水稻BT型不育细胞质(农虎26A和丰锦A不育系)的线粒体基因产物比可育细胞质(农虎26B和丰锦B保持系)缺少一个22KD多肽。它反应了BT型不育细胞质线粒体基因组中有关育性的基因变异。不育系与恢复系杂交后,杂种F_1的育性虽然恢复,但是它的线粒体基因产物中仍然缺少22KD多肽。然而,在杂种F_1的线粒体蛋白质的电泳染色图谱中则显示出一个22KD多肽条带。杂种F_1中的这个22KD多肽是核基因产物。它弥补了线粒体基因组中育性基因的缺陷。     

植物细胞质雄性不育及其育性恢复的分子基础

植物细胞质雄性不育是广泛存在于高等植物中的现象,其表现为母性遗传、花粉败育,但雌蕊正常。细胞质雄性不育在杂交种子生产中起着重要作用,研究其分子作用机制有利于更有效地利用细胞质雄性不育。随着一些不育基因和恢复基因相继被克隆,人们对一些细胞质雄性不育和恢复系统的分子作用机理已经有一定了解。本文综述了近年来对植物细胞质雄性不育基因和恢复基因作用机理研究的进展。     

植物线粒体与细胞质雄性不育研究进展

本文从能量代谢与植物细胞质雄性不育(CMS)、线粒体的结构和数量与CMS、线粒体DNA多态性与CMS、线粒体基因转录与CMS、线粒体多肽差异与CMS几个方面介绍了植物线粒体与CMS的关系。并介绍了与CMS相关的线粒体基因研究进展并对CMS形成的分子机制进行了探讨。     

植物细胞质雄性不育分子机理研究进展

本文从线粒体基因组、线粒体基因、线粒体转录RNA、线粒体蛋白、转基因植物以及花粉败育机理六个方面详细介绍了植物细胞质雄性不育分子生物学研究的技术和方法。综述了植物细胞质雄性不育分子机理研究的进展 ,并对植物细胞质雄性不育分子机理的前景作了展望。     

普通小麦三种细胞质雄性不育系线粒体DNA的比较研究

对细胞质分别来源于粘果山羊草（Ａｅ．ｋｏｔｓｃｈｙｉ）、偏凸山羊草（Ａｅ．ｖｅｎｔｒｉｃｏｓａ）、提莫菲维（Ｔ．ｔｉｍｏｐｈｅｅｖｉ）的３种普通小麦雄性不育系,其相应保持系和共有的一种恢复系的ｍｔＤＮＡ进行了ＲＦＬＰ比较分析。发现Ｋ型和Ｖ型不育系的ｍｔＤＮＡ在组织结构上不同于Ｔ型,说明Ｋ、Ｖ型不育系是有别于Ｔ型的两种新不育类型。Ｋ型、Ｖ型不育系的ｍｔＤＮＡ与保持系和恢复系显著不同,推测ｍｔＤＮＡ与小麦细胞质雄性不育性有关。实验同时发现Ｔ型不育系与其保持系的ｍｔＤＮＡ非常相似,对这种相似性的原因进行了讨论。     

甘蓝型油菜细胞质雄性不育材料1575A的分子鉴定

根据已报道的油菜育性相关基因orf224、orf138和orf222设计引物对1575A、陕3A、Ogura和nap等4份甘蓝型油菜的mtDNA进行PCR扩增.结果显示:引物对Syworf1382/ Xyworf1382在1575A和Ogura的mtDNA中均有1000 bp左右的扩增片段;测序结果表明,在1575A中的该扩增片段包含已报道基因orf138(登录号为AB055435)的全部编码序列;该引物对在陕3A和nap中都没有相应扩增片段.引物对Syworf222/Xyworf222在除Ogura外的其他3个材料的mtDNA中都有196 bp左右的扩增片段;测序结果显示,扩增产物与已报道基因orf222(登录号为DQ872162)同源性为100%.初步推测1575A属于Ogu CMS的改良类型.     

Genetics of Male and Female Sterility in Hybrids of Drosophila pseudoobscura and D. persimilis

The genetic basis of male and female sterility in hybrids of Drosophila pseudoobscura-Drosophila persimilis was studied using backcross analysis. Previous studies indirectly assessed male fertility by measuring testis size; these studies concluded that male sterility results from an X chromosome-autosome imbalance. By directly scoring for the production of motile sperm, male sterility is shown to be largely due to an incompatibility between genes on the X and Y chromosomes of these two species. These species have diverged at a minimum of nine loci affecting hybrid male fertility. Semisterility of hybrid females appears to result from an X chromosome-cytoplasm interaction; the X chromosome thus has the largest effect on sterility in both male and female hybrids. This is apparently the first analysis of the genetic basis of female sterility, or of sterility/inviability affecting both sexes, in an animal hybridization.     

主要农作物细胞质雄性不育系育性恢复基因研究进展

提升作物产量、抗逆性和品质的主要手段之一是利用杂种优势,其中细胞质雄性不育/恢复(CMS/Rf)系统是应用最广的雄性不育系统。研究细胞质雄性不育系育性恢复机理是"三系"法选育的重要分子遗传学基础。目前,各个作物已经创制了不同类型的不育系。随着分子技术、基因组学和测序技术的深入,大量育性恢复基因已被定位,且部分已被克隆和功能鉴定。针对主要作物中恢复基因的遗传模式,分子标记定位、克隆及CMS/Rf系统在杂交育种中的应用进行了系统总结。希望本文能为今后恢复系分子标记辅助选育,或利用转基因、基因编辑手段创制新恢复系提供思路。