植物叶色突变体

叶色变异是比较常见的突变性状。叶色突变体在基础研究和育种工作中越来越显得重要。文章概述叶色突变体的分类方法、来源、遗传方式和突变的分子机制,着重介绍其应用价值及前景。     

植物叶绿素突变体及其分子机理的研究进展

叶绿素是植物叶绿体内参与光合作用的重要色素,叶绿素突变是一种明显的性状突变,其在理论研究和实际应用方面具有重要的意义。综述了植物叶绿素突变体的种类、遗传及突变的分子机理研究进展,着重介绍了突变的分子机理研究进展。     

玉米体细胞突变体筛选研究

综述了近10多年来在玉米体细胞突变体筛选研究方面的研究进展;玉米突变体筛选程序的改进;产生能稳定遗传突变的机理等。指出开展玉米突变体筛选育种更具可行性与必要性。     

植物叶色白化研究进展

植物叶色白化是一类明显和常见的叶绿素缺失突变,在植物光合作用机理、激素生理、核一质基因组相互作用、遗传育种等理论研究和实际应用方面均具有无可替代的价值。主要综述了近年来国内外有关白化突变体与叶绿素合成的关系、影响白化的内外因素、相关基因的克隆以及克服白化的途径等方面的研究进展,旨在为深入研究植物叶色白化突变提供参考。     

水稻叶绿素合成缺陷突变体及其生物学研究进展

叶绿素是植物叶绿体内参与光合作用的重要色素,叶绿素合成缺陷突变是一类明显的性状突变,其在理论研究和实际应用方面均具有重要的意义。本文介绍了国内外在水稻叶绿素合成缺陷突变体的发掘、作用机理及其基因定位等方面的研究进展。     

小麦诱发突变技术育种研究进展

诱发突变育种技术是利用射线、离子、中子等物理辐射因素及空间环境诱变种子或植物离体组织,获得有益突变体,缩短育种周期的育种技术。据国际诱变育成品种数据库的不完全统计,截至2016年5月,世界上60多个国家在214种植物上诱变了超过3 200个正式发布的突变品种,21个国家诱变了254个小麦突变体,其中我国诱变小麦164个,占总量超过64%而位居世界第一。综述了诱变技术在小麦育种方面的成就,概述了获得的小麦农艺性状、产量、品质等性状突变,并对今后小麦诱变育种的目标及方法进行了展望。以期为小麦诱变育种的进一步发展提供借鉴,促进现代物理农业的应用及发展。     

水稻叶色基因克隆与分子机制研究进展

叶色突变体是研究水稻光合作用、叶绿素合成与降解及其生长发育调控机制的重要材料,而且在水稻杂交制种、提高生物量等方面具有较高的实际应用价值。目前,超过120个水稻叶色相关基因被克隆,分布在水稻12条染色体上,其中第3号染色体克隆的基因最多。水稻叶色调控机制涉及多个调控途径,包括色素生物合成与降解、质体转录复合物、转录后修饰、核质信号转导、叶绿体蛋白酶以及转录因子与表观遗传。本文从水稻叶色遗传机理与基因克隆、分子调控机制及其在水稻育种上的应用进行了总结与展望,以期为水稻高光合育种及挖掘适用于杂交制种的水稻叶色种质资源提供依据。     

用培养细胞筛选对农业有价值的几种突变体

从高等植物细胞培养筛选突变体与体细胞无性系变异、原生质体融合和把外源基因导入植物体,都是在细胞中产生新遗传组合的途径,同属于植物细胞遗传操作的范畴;与育种关系密切。突变育种广泛地包含诱导出突变的任何过程,故Reisch也把体细胞无性系变异视为突变育种的一种形式。十多年来,有些人积极研究用培养细胞选择高等植物突     

芝麻诱发突变技术育种研究进展

近年来,空间环境诱变、离子束辐照及核辐射传统诱变技术在我国改良农作物和发掘新基因中应用日趋活跃。诱发突变技术应用于芝麻新材料创制及新品种选育始于1950年,据国际诱变育成品种数据库的不完全统计,截至2017年3月,世界上60多个国家在217种植物上诱变了3 246个正式发布的突变品种,8个国家诱变了25个芝麻突变体,其中我国诱变5个芝麻突变体,占总量20%而位居世界第二。综述了芝麻诱变育种的成果及诱变获得的芝麻农艺性状、抗病性等性状突变,并对今后芝麻诱变育种的目标及方法进行了展望,以期为研究芝麻功能基因组学提供丰富的多样材料及芝麻种质创新提供重要的理论参考。     

德国油菜高油酸育种情况(英文)

德国近年来油菜高油酸育种的一些情况,其中包括高油酸育种的意义,育种方法,高油酸突变体的遗传特点,高油酸-低亚麻酸育种的可能性和高油酸油菜的应用前景等,对于我国育种新技术的改进、改良和创新研究有一定的意义.     

Induction and isolation of pigmentation mutants of Porphyra yezoensis (Bangiales, Rhodophyta) by heavy-ion beam irradiation

The present study describes the isolation of pigmentation mutants of Porphyra yezoensis Ueda induced by heavy-ion beam irradiation for the first time. The gametophytic blades were irradiated with ¹²C⁺⁶ ion beams within a dose range of 25–400 Gy. From the survival rate and cell growth of the irradiated blades, it is suggested that a dose of 150 Gy or less is suitable to induce mutation for the isolation of mutants of P. yezoensis . After irradiation, red, green and deep reddish brown-colored gametophytic blades developed from archeospores that were released from each of the mutated cell clusters of the respective different colors, and the red mutant strain (IBY-R1) and green mutant strain (IBY-G1) were established as a conchocelis colony in culture. Blades of the mutants were characterized by their growth and photosynthetic pigment contents compared with those of the wild-type. From these results, it is clear that heavy-ion beam mutagenesis will be an effective tool for genetic and breeding studies of Porphyra , and also for other algal research.     

The cyl genes of Streptococcus agalactiae are involved in the production of pigment

The cyl genes of Streptococcus agalactiae are required for the production of hemolysin. Based on the observation that nonhemolytic S. agalactiae mutants do not produce pigment, a close genetic linkage between hemolysin and pigment has been postulated. To investigate this genetic linkage and to identify genes involved in the production of the S. agalactiae pigment, we screened mutant libraries for nonpigmented clones. Four distinct mutants were isolated with a nonpigmented and nonhemolytic phenotype. The mutations had occurred either in known cyl genes or in two open reading frames located immediately downstream. These novel genes are cotranscribed with the cyl gene cluster and were designated cylF and cylI. Our data indicate that identical genes participate in the production of S. agalactiae hemolysin and pigment.     

Functional genomics tools for the analysis of zebrafish pigment

Genetic model organisms are increasingly valuable in the post-genomics era to provide a basis for comparative analysis of the human genome. For higher order processes of vertebrate pigment cell biology and development, the mouse has historically been the model of choice. A complementary organism, the zebrafish (Danio rerio), shares many of the signaling and biological processes of vertebrates, e.g. neural crest development. The zebrafish has a number of characteristics that make it an especially valuable model for the study of pigment cell biology and disease. Large-scale genetic screens have identified a collection of pigmentation mutants that have already made valuable contributions to pigment research. An increasing repertoire of genomic resources such as an expressed sequence tag-based Gene Index (The Institute for Genomic Research) and improving methods of mutagenesis, transgenesis, and gene targeting make zebrafish a particularly attractive model. Morpholino phosphorodiamidate oligonucleotide (MO) 'knockdown' of pigment gene expression provides a non-conventional antisense tool for the analysis of genes involved in pigment cell biology and disease. In addition, an ongoing, reverse-genetic, MO-based screen for the rapid identification of gene function promises to be a valuable complement to other high-throughput microarray and proteomic approaches for understanding pigment cell biology. Novel reagents for zebrafish transgenesis, such as the Sleeping Beauty transposon system, continue to improve the capacity for genetic analysis in this system and ensure that the zebrafish will be a valuable genetic model for understanding a variety of biological processes and human diseases for years to come.     

High monospore-producing mutants obtained by treatment with MNNG in Porphyra yezoensis Ueda (Bangiales,Rhodophyta)

Hydrobiologia - Two high monospore-producing pigmentation mutants were obtained by treatment with MNNG in Porphyra yezoensis Ueda. The mutants produced many monospores in young gametophytic blades...     

On the Development of Pigment Patterns in Amphibians

SYNOPSIS. Pigmentary mutants in amphibians provide importantvehicles for studying basic problems in development. Some ofthese mutants exert influences on the tissue environment inwhich the chromatophores differentiate and others involve theexpression of pigment in specific types of pigment cells. Melanophoresare the best known of all chromatophores, and albinism has beenmuch studied. Genes controlling its expression may operate atdifferent levels. Some are involved in the production of tyrosinase,whileothers affect the melanosomal matrix. In contrast, melanoidmutants are characterized by an overproduction of eumelanin,usually through the differentiation of an excessive number ofmelanophores. Melanoid mutants of the axolotl also exhibit a great diminutionin xanthophore and iridophore number, and the same seems tobe true of some melanoid-like mutants of leopard frogs. Thepteridine pigments of xanthophores and purines of iridophoresare often products of xanthine dehydrogenase (XDH) activity,and it is suspected that the expression of the melanoid phenotypemay result from a genetic defect involving this enzyme. Thisis supported by experiments involving the administration ofan XDH inhibitor, allopurinol, to normal larvae. This inhibitorresults in the production of partial phenocopies of the melanoidcondition. Blue mutants involving either partial or completediminution of xanthophore and iridophore pigments may also bebased upon deficient XDH activity.     

Spheroplast fusion as a mode of genetic recombination in mycobacteria

Spheroplasts were prepared from two carotenoid pigment mutants of Mycobacterium aurum named NgR9 and A11, which were obtained by the chemical mutagenesis of the wild type strain A+ with N-methyl-N'-nitro-N-nitrosoguanidine. The carotenoid pigments and the alpha- and beta-mycolic acids were taken as genetic markers and the recombinants were selected on the basis of their colour on L?wenstein-Jensen medium. Spheroplasts of the two mutants were mixed in a 1:1 ratio and were treated with 40% (w/v) polyethylene glycol 6000 for 5 min at 37 degrees C. The frequency of NgR9 X A11 recombination in optimal conditions was about 2.5 X 10(-3). The recombinants selected on the basis of their carotenoid pigment profile were also tested for their alpha- and beta-mycolic acids as a second genetic marker. The results were further confirmed by electron microscopy. The optimal conditions for spheroplast fusion as a mode of genetic recombination in M. aurum are described.     

Hyperspectral imaging techniques for rapid identification of Arabidopsis mutants with altered leaf pigment status

The spectral reflectance signature of living organisms provides information that closely reflects their physiological status. Because of its high potential for the estimation of geomorphic biological parameters, particularly of gross photosynthesis of plants, two-dimensional spectroscopy, via the use of hyperspectral instruments, has been widely used in remote sensing applications. In genetics research, in contrast, the reflectance phenotype has rarely been the subject of quantitative analysis; its potential for illuminating the pathway leading from the gene to phenotype remains largely unexplored. In this study, we employed hyperspectral imaging techniques to identify Arabidopsis mutants with altered leaf pigment status. The techniques are comprised of two modes; the first is referred to as the 'targeted mode' and the second as the 'non-targeted mode'. The 'targeted' mode is aimed at visualizing individual concentrations and compositional parameters of leaf pigments based on reflectance indices (RIs) developed for Chls a and b, carotenoids and anthocyanins. The 'non-targeted' mode highlights differences in reflectance spectra of leaf samples relative to reference spectra from the wild-type leaves. Through the latter approach, three mutant lines with weak irregular reflectance phenotypes, that are hardly identifiable by simple observation, were isolated. Analysis of these and other mutants revealed that the RI-based targeted pigment estimation was robust at least against changes in trichome density, but was confounded by genetic defects in chloroplast photorelocation movement. Notwithstanding such a limitation, the techniques presented here provide rapid and high-sensitive means to identify genetic mechanisms that coordinate leaf pigment status with developmental stages and/or environmental stress conditions.     

草鱼同工酶基因座位多态性的初步研究

采用垂直淀粉凝胶电泳及特异性组织化学染色技术研究了25尾草鱼的6种同工酶系统(LDH,MDH,ADH,GDH,IDH,EST)约18—23个基因座位的遗传变异型。有7个基因座位(s-Mdh-A,Adh—B,Gdh-1,Gdh-2,Est-1,Est-6,Est-14)具有多态性,在其中4个基因座位(s-Mdh—A,Adh-B,Gdh-1,Est-1)上观察到的基因型频率与Hardy-Weinberg定律相符．实验表明草鱼的同工酶基因座位具有明显的多态性。这一结果为草鱼的人工选种和定向育种的可能性提供了依据。对草鱼GDH,EST同工酶的遗传基础、亚基组成以及酶变异的机理等问题进行了讨论。     

Molecular features of a defined genetic marker for the determination of the Porphyra tenera lineage

Nucleotide sequences of the nuclear SSU rDNA and ITS1 are presented as a defined genetic marker for Porphyra tenera as a species. Exon nucleotide sequences were identical within all the P. tenera specimens. Intron nucleotide sequences varied between populations. The introns and ITS1 variations are presented as defined genetic markers to establish the Porphyra tenera strains. Wild-collected thalli identified by morphological systematics, from five populations of Porphyra tenera throughout Japan, were discriminated by comparing sequences of the various regions utilizing the results of this and previous studies.     

Genetic analysis of melanophore development in zebrafish embryos

Vertebrate pigment cells are derived from neural crest, a tissue that also forms most of the peripheral nervous system and a variety of ectomesenchymal cell types. Formation of pigment cells from multipotential neural crest cells involves a number of common developmental processes. Pigment cells must be specified; their migration, proliferation, and survival must be controlled and they must differentiate to the final pigment cell type. We previously reported a large set of embryonic mutations that affect pigment cell development from neural crest (R. N. Kelsh et al., 1996, Development 123, 369-389). Based on distinctions in pigment cell appearance between mutants, we proposed hypotheses as to the process of pigment cell development affected by each mutation. Here we describe the cloning and expression of an early zebrafish melanoblast marker, dopachrome tautomerase. We used this marker to test predictions about melanoblast number and pattern in mutant embryos, including embryos homozygous for mutations in the colourless, sparse, touchdown, sunbleached, punkt, blurred, fade out, weiss, sandy, and albino genes. We showed that in homozygous mutants for all loci except colourless and sparse, melanoblast number and pattern are normal. colourless mutants have a pronounced decrease in melanoblast cell number from the earliest stages and also show poor melanoblast differentiation and migration. Although sparse mutants show normal numbers of melanoblasts initially, their number is reduced later. Furthermore, their distribution indicates a defect in melanoblast dispersal. These observations permit us to refine our model of the genetic control of melanophore development in zebrafish embryos.