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1.
单倍体小麦染色体加倍的研究   总被引:14,自引:0,他引:14  
从七十年代利用花药培养技术获得单倍体植株以来,单倍体植物在育种应用上的潜力日益显示出来。但是这种潜力只有使单倍体植物加倍成为纯合二倍体才有可能发挥。因此,对于单倍体植物的染色体加倍,许多植物育种工作者进行过多方面的试验研究,提出过多种加倍方法,其中秋水仙碱法应用最为广泛,但加倍成功率并不理想,植株死亡率也较高。近年来有人用秋水仙碱和DMSO结合处理单倍体植株,加倍效果显著提高。就小麦来说,最高成功率有达9.0%  相似文献   

2.
《遗传》2016,(11)
单倍体(Haploid)是指含有配子染色体数目的个体,对其进行基因组加倍可以快速获得纯合双单倍体(Doubled haploid,DH)。单倍体和双单倍体在植物品种选育、突变体筛选、基因功能鉴定、细胞学研究、遗传群体构建等方面具有重要作用,是近年来植物领域的一大研究热点。本文从单倍体和双单倍体的产生途径、鉴定、形成机理以及应用等方面较全面地综述了单倍体的最新研究进展,为单倍体的研究利用作一定的参考。  相似文献   

3.
从七十年代利用花药培养技术获得大量花 粉单倍体植株以来,花培技术在育种上应用的 潜力日益显示出来,就小麦来说,已有一些优良 的花培新品系在试种和推广。但花粉植株是单 倍体不能结实,需要设法使其加倍恢复成二倍 体(普通小麦单倍体植株是3x,加倍则成6x)o 关于单倍体植株染色体加倍的方法,通常用秋 水仙素溶液浸泡幼苗基部[1],我们也曾多次用 这种方法,但加倍结实率并不很理想。  相似文献   

4.
水稻单倍体再生苗的人工加倍及其后代遗传学观察   总被引:1,自引:0,他引:1  
几年来的花培实践表明,水稻花粉植株中单倍体比例一般占30—50%。随着花药培养技术的不断发展,单倍体植株的人工加倍已日益成为单倍体育种研究的重要内容之一。由于籼稻花粉植株诱导频率较低,加上单倍体植株娇嫩细弱,目前尚缺乏高效而又安全的加倍方法。  相似文献   

5.
烟草花药培养成功之后,国内外育种工作者用这一方法在烟草育种上做出了贡献,并在培养技术、染色体加倍方法、单倍体和加倍单倍体特性、花粉单倍体植株性状遗传变异及生活力等方面都进行了不同程度的研究。然而对花粉单倍体植株的遗传学问题,目前报道的为数不多,尚有不少有待进一步探讨的问题。  相似文献   

6.
尽管目前应用组培技术来生产单倍体植株已成为一条重要的育种途径,但常常却难以使单倍体植株的染色体数加倍。染色体加倍事件可自发产生或可用如秋水仙碱的抗有丝分裂剂来处理单倍体植株而诱发产生,或者是离体或植株脱离于离体条件后产生的。然而自发加倍的发生频率非常低,用有毒化学药品秋水仙碱处理又较为困难,需要量相当大,可能还会引起植株矮化,延迟开花,诱变,倍性嵌合及结籽量低。 日本Osaka Prefecture大学研究人员发现,在离体培养之前,若先将花芽上切下的花药直接浸于秋  相似文献   

7.
禾木科植物染色体消除型远缘杂交的研究进展   总被引:1,自引:0,他引:1  
植物远缘杂交是作物育种中广泛应用的技术。除了核型稳定的种间杂交可以获得杂种以外,还可以利用核型不稳定的种间杂交后父本染色体消除的现象,通过胚培养和染色体加倍处理获得加倍单倍体(DH)植株。然而从小麦×玉米杂交获得的DH后代与其理论上应完全同质的遗传表现却不相符,总有2~5%的DH植株发生了形态学变异。最近的研究证明。通过小麦×玉米的受精作用,一些玉米特异DNA可以被转移到小麦DH后代的基因组中。  相似文献   

8.
油菜是食用油、优质饲料蛋白的重要来源,杂种优势利用是油菜培育优势性状最重要的手段,且提高亲本的选育效率对优质品种的培育具有积极的推动作用。现有油菜育种技术存在效率低、周期长、盲目性大、应用范围有限等诸多问题,不适于油菜产业快速发展的需求。双单倍体诱导育种技术是近年来新兴的一种快速选育油菜新品种的技术方法。该技术以操作简便、应用范围广、效率高等优势被广泛应用于油菜新品种的选育过程中。从油菜双单倍体诱导技术创新研究的发现、作用表现、诱导机制、作用价值等方面系统地综述了油菜双单倍体诱导技术的研究进展,展望了油菜双单倍体诱导技术的应用前景,以期为未来油菜双单倍体诱导技术以及其他作物诱导系的研究和利用提供参考。  相似文献   

9.
李朝灿 《遗传》1985,7(3):5-8
几年来的花培实践表明,水稻花粉植株中 单倍体比例一般占30-50外。随着花药培养技 术的不断发展,单倍体植株的人工加倍已日益 成为单倍体育种研究的重要内容之一。由于釉 稻花粉植株诱导频率较低,加上单倍体植株娇 嫩细弱,目前尚缺乏高效而又安全的加倍方法。 此外,有关人工加倍后代的遗传学观察并不多 见。为了探索水稻单倍体高效安全、简便经济 的加倍方法,我们自1978年以来进行水稻单倍 体再生苗人工加倍及其后代遗传学观察研究, 现将结果报告如下。  相似文献   

10.
玉米自交系间的杂交优势,已被广泛利用。但是,用常规育种法,从选育自交系到配成杂交种,一般需要8~10年,而且手续繁杂,有时还不能保证纯度。如果利用单倍体育种技术,就可能在短时期内获得纯系和进行配合力的测定,比较准确可靠地选育出符合育种目标的自交系和杂交种,可以缩短玉米育种的年限。  相似文献   

11.
Androgenesis,gynogenesis, and parthenogenesis haploids in cucurbit species   总被引:1,自引:0,他引:1  
Haploids and doubled haploids are critical components of plant breeding. This review is focused on studies on haploids and double haploids inducted in cucurbits through in vitro pollination with irradiated pollen, unfertilized ovule/ovary culture, and anther/microspore culture during the last 30 years, as well as comprehensive analysis of the main factors of each process and comparison between chromosome doubling and ploidy identification methods, with special focus on the application of double haploids in plant breeding and genetics. This review identifies existing problems affecting the efficiency of androgenesis, gynogenesis, and parthenogenesis in cucurbit species. Donor plant genotypes and surrounding environments, developmental stages of explants, culture media, stress factors, and chromosome doubling and ploidy identification are compared at length and discussed as methodologies and protocols for androgenesis, gynogenesis, and parthenogenesis in haploid and double haploid production technologies.  相似文献   

12.
Novel technologies in doubled haploid line development   总被引:1,自引:0,他引:1       下载免费PDF全文
haploid inducer line can be transferred (DH) technology can not only shorten the breeding process but also increase genetic gain. Haploid induction and subsequent genome doubling are the two main steps required for DH technology. Haploids have been generated through the culture of immature male and female gametophytes, and through inter‐ and intraspecific via chromosome elimination. Here, we focus on haploidization via chromosome elimination, especially the recent advances in centromere‐mediated haploidization. Once haploids have been induced, genome doubling is needed to produce DH lines. This study has proposed a new strategy to improve haploid genome doubling by combing haploids and minichromosome technology. With the progress in haploid induction and genome doubling methods, DH technology can facilitate reverse breeding, cytoplasmic male sterile (CMS) line production, gene stacking and a variety of other genetic analysis.  相似文献   

13.
Zhang Z  Qiu F  Liu Y  Ma K  Li Z  Xu S 《Plant cell reports》2008,27(12):1851-1860
In vivo haploid production induced by inducer lines derived from Stock 6 is widely used in breeding program of maize (Zea mays L.), but the mechanisms behind have not yet been fully understood. In this study, average frequency of haploid induction in four inbred lines by Stock 6-derived inducer line HZI1 was above 10%. About 0.2% kernels from the cross Hua24 x HZI1 had mosaic endosperm showing yellow shrunken parts from Hua24 to normal parts with purple aleurone from HZI1. Individual lagged chromosomes and micronuclei were observed in mitotic cells of ovules pollinated by HZI1. Above 56.4% of the radicles from the kernels with purple aleurone and colorless embryos were mixoploid (2n = 9-21), and more than 45.22% cells were haploid cells (2n = 10) in three crosses. More than 62.5% of the radicles from the kernels with purple aleurone and purple embryos were mixoploid (2n = 9-21) having 54.27% cells with 2n = 20. SSR analysis showed that all haploids from the cross Hua24 x HZI1 shared the same genomic compositions as Hua24 except for plants Nos. 862 and 857 with some polymorphic DNA bands. The results revealed that chromosome elimination after fertilization caused the haploid production in maize.  相似文献   

14.
The range of genetic variation of spontaneous chromosome doubling frequency of maize haploid plantlets derived from in vitro anther culture was evaluated. When regeneration is obtained by direct embryo-genesis, bypassing the callus phase, it appears that the frequency of spontaneous doubling may exceed 40 of the regenerated plantlets. This high frequency may be one consequence of the use of doubled haploid lines derived from anther culture and spontaneous chromosome doubling. We also report an increase, by more than 50, of the productivity of diploid fertile regenerated plantlets produced by colchicine supplemented medium during the cold shock pretreatment of the microspores inside the anthers. Optimization of the treatments and the anther culture procedure are discussed. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

15.
Frisch M  Melchinger AE 《Genetics》2007,176(1):477-488
The expectation of the parental genome contribution to inbred lines derived from biparental crosses or backcrosses is well known, but no theoretical results exist for its variance. Our objective was to derive the variance of the parental genome contribution to inbred lines developed by the single-seed descent or double haploid method from biparental crosses or backcrosses. We derived formulas and tabulated results for the variance of the parental genome contribution depending on the chromosome lengths and the mating scheme used for inbred line development. A normal approximation of the probability distribution function of the parental genome contribution fitted well the exact distribution obtained from computer simulations. We determined upper and lower quantiles of the parental genome contribution for model genomes of sugar beet, maize, and wheat using normal approximations. These can be employed to detect essentially derived varieties in the context of plant variety protection. Furthermore, we outlined the application of our results to predict the response to selection. Our results on the variance of the parental genome contribution can assist breeders and geneticists in the design of experiments or breeding programs by assessing the variation around the mean parental genome contribution for alternative crossing schemes.  相似文献   

16.
Liu K  Goodman M  Muse S  Smith JS  Buckler E  Doebley J 《Genetics》2003,165(4):2117-2128
Two hundred and sixty maize inbred lines, representative of the genetic diversity among essentially all public lines of importance to temperate breeding and many important tropical and subtropical lines, were assayed for polymorphism at 94 microsatellite loci. The 2039 alleles identified served as raw data for estimating genetic structure and diversity. A model-based clustering analysis placed the inbred lines in five clusters that correspond to major breeding groups plus a set of lines showing evidence of mixed origins. A "phylogenetic" tree was constructed to further assess the genetic structure of maize inbreds, showing good agreement with the pedigree information and the cluster analysis. Tropical and subtropical inbreds possess a greater number of alleles and greater gene diversity than their temperate counterparts. The temperate Stiff Stalk lines are on average the most divergent from all other inbred groups. Comparison of diversity in equivalent samples of inbreds and open-pollinated landraces revealed that maize inbreds capture <80% of the alleles in the landraces, suggesting that landraces can provide additional genetic diversity for maize breeding. The contributions of four different segments of the landrace gene pool to each inbred group's gene pool were estimated using a novel likelihood-based model. The estimates are largely consistent with known histories of the inbreds and indicate that tropical highland germplasm is poorly represented in maize inbreds. Core sets of inbreds that capture maximal allelic richness were defined. These or similar core sets can be used for a variety of genetic applications in maize.  相似文献   

17.
Ploidy variation of pronamide-treated maize calli during long term culture   总被引:1,自引:0,他引:1  
Summary Anther-derived calli of corn were treated with 10 M pronamide for 2, 3 and 4 days. The ploidy level of the calli was then evaluated using flow cytometry, at different times after the treatment. Untreated haploid calli did not change in ploidy level for 97 days but by 466 days, there were up to 50% diploid or higher ploidy cells thus showing that spontaneous doubling may occur during corn calli subculture with this genotype. Pronamide treatment did increase the percentage of diploid and tetraploid cells and by 466 days, all of the lines showed an additional change toward higher ploidy levels. This change may be due to spontaneous chromosome doubling or to differential cell cycle times of cells with different ploidy levels. The ploidy level of plants regenerated from the cultures was determined by counting the guard cell chloroplast numbers and the correlation with the ploidy level of the cultures was r2=0.84. These studies show that pronamide treatments can increase haploid maize callus chromosome numbers and that spontaneous chromosome doubling can occur with time in maize callus.  相似文献   

18.
Information regarding the genetic diversity and genetic relationships among elite inbred lines is necessary to improve new cultivars in maize breeding programs. In this study, genetic diversity and genetic relationships were investigated among 84 waxy maize inbred lines using 50 SSR markers. A total of 269 alleles were identified at all the loci with an average of 5.38 and a range between 2 and 13 alleles per locus. The gene diversity values varied from 0.383 to 0.923 with an average of 0.641. The cluster tree generated using the described SSR markers recognized two major groups at 32% genetic similarity. Group I included 33 inbred lines while group II included 51 inbred lines. The clustering patterns of most of the waxy maize inbred lines did not clearly agree with their source, pedigree or geographic location. The average GS among all inbred lines was 35.7 ± 10.8. Analysis of waxy maize inbred lines collected from Korea and China at 50 SSR loci revealed higher values of average number of alleles (4.9) and gene diversity (0.638) in Korean inbred lines as compared to Chinese inbred lines (3.5 and 0.563, respectively). The information obtained from the present studies would be very useful for maize breeding programs in Korea.  相似文献   

19.
The flow karyotypes of different maize (Zea mays L.) inbred and hybrid lines were analyzed. The accumulation and isolation of large quantities of high-quality metaphase chromosomes from root tips was achieved from many kinds of maize lines. The chromosome suspensions were prepared by a simple slicing method from synchronized maize root tips and analyzed by flow cytometry. Variations of experimental flow karyotypes were detected among inbred and hybrid lines in terms of the positions and/or the numbers of chromosome peaks. The 2C DNA amount among eight inbred lines ranged from 5.09 to 5.52 pg. The selection of appropriate maize lines is critical for sorting specific single chromosome types. At least five different chromosome types can be discriminated and sorted from five maize lines. The variability of DNA content in maize chromosome 1 was 9.1%, ranging from 0.685 to 0.747 pg. Differences were detected in the DNA content of homologous chromosome 1 of hybrid lines.  相似文献   

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