秋水仙素诱导甘菊多倍体研究

以甘菊种子为试验材料,研究了不同秋水仙素浓度和处理时间对甘菊多倍体诱导的影响。结果表明:500mg/L的秋水仙素水溶液浸渍种子12h,变异率为23%,达到了极显著差异。根尖染色体压片检查表明,四倍体染色体数为2n=4x=36,并且获得了同源四倍体甘菊1株(2n=4x=36)。四倍体植株表现出叶片下表皮气孔保卫细胞变大,叶绿体数变多,叶片变小,花径变大,舌状花数目减少,管状花数目增多。     

一系法杂交水稻研究的技术策略探讨

通过一系法利用和固定水稻的远缘杂种优势是一项具有极大诱惑力但难度颇大的科研难题。我国水稻无融合生殖研究尚处在探索性阶段,还没有筛选到具有实用价值的无融合生殖种质。由于多倍体水稻的有性生殖能力明显变弱,在多倍性水平筛选和创造水稻无融合生殖种质有可能成为一系法杂交稻研究的突破口。     

Chimerical structure and carotenoid inheritance in Chrysanthemum morifolium (Ramat.)

Summary Progeny analysis showed that yellow-flowered chrysanthemum sports with carotenoid only in L1 are indistinguishable from their white progenitors in breeding behaviour; those with carotenoid in L2 breed quite differently. Chimerical structure has, therefore, to be considered when analysing flower colour inheritance data. Segregations were consistent with the action of the single dominant gene I. Such simply inherited characters may be useful in studies to distinguish between the several alternative patterns of inheritance which can be suggested in the species.     

水产动物染色体操作育种研究进展

随着科学技术的高速发展,我国水产动物育种技术有了很大的提高。染色体操作育种技术作为现代遗传育种的重要组成部分,在水产动物育种中得到了广泛应用。本文就近年来水产动物染色体操作育种技术,包括人工诱导多倍体与检测多倍体的方法、雌核发育和雄核发育的研究现状和发展前景进行综述。     

秋水仙素离体诱导分蘖洋葱茎尖多倍体的研究

以分蘖洋葱品系Z-018的茎尖外植体为材料,通过不同浓度秋水仙素及处理时间对分蘖洋葱茎尖细胞染色体的诱导,以获得倍性变异的分蘖洋葱材料。结果表明:当秋水仙素质量分数为0.01%,处理4 d时,多倍体的诱导率最高,可达42.22%。得到的变异植株与正常二倍体植株相比,表现为生长缓慢,叶片、假茎及根系粗壮,叶片的气孔保卫细胞变大,密度减小。进一步对根尖染色体数目进行鉴定及利用流式细胞仪分析测定DNA含量,在149株变异株中,获得倍性变异株117株,其中四倍体材料81株,占变异总数的54.36%。     

杉木多倍体变异苗诱导及倍性鉴定

为了探究秋水仙素处理对杉木萌动种子的诱变效应,以3种杉木种子为材料,用0.9%的秋水仙素溶液浸泡处理后播种,60d后统计变异苗得率并用流式细胞仪检测变异苗不同部位的细胞倍性。结果表明,经秋水仙素溶液浸泡处理后,3种来源的杉木种子变异苗得率差异显著,全同胞种子Z3#得率最高,为23.45%;3种来源的杉木种子经秋水仙素处理后所得的变异苗均表现为胚根短缩,下胚轴下部明显膨大。流式细胞仪检测表明,胚根部分57.2%的细胞为混倍体细胞,下胚轴下部42.04%的细胞为四倍体细胞,下胚轴中部四倍体细胞所占比例为9.15%,下胚轴上部和子叶部分的细胞均为二倍体细胞;秋水仙素溶液浸泡种子可诱导获得表型特征及细胞倍性发生明显变异的变异苗。本研究结果为进一步开展杉木同源多倍体新种质的创制奠定了基础。     

Peroxidase isozyme differences in tall fescue cultivars and allopolyploid accessions

Summary The use of isoelectric focusing for the isozymic identification of cultivars and wild forms in tall fescue (Festuca arundinacea Schreb.) and determination of ploidy effects was investigated. Peroxidase zymograms from allopolyploid accessions (4x, 6x, 8x, and 10x, x=7) and randomly sampled plants of the cultivars Kenhy, Kentucky 31, and Missouri 96, were compared for band number, position, and staining intensity. There was little isozymic variation among plants in the tetraploid and hexaploid, but considerably more in the octoploid and decaploid members of the series. Yet no significant effects of ploidy on isozyme complexity or band number were observed. There were no consistent differences in band number, position, or frequencies among the three cultivars in spite of their diverse parentage. Isoclectric focusing can be used successfully in tall fescue, but the limited variability of the peroxidases encourages investigation of other isozyme systems in the future.Contribution from the Missouri Agricultural Experiment Station. Journal Series No. 8627. Research supported by USDA-SEA Competitive Research Grant 5901-0410-9-0366-0.     

A generalized framework for AMOVA with multiple hierarchies and ploidies

The analysis of molecular variance (AMOVA) is a widely used statistical method in population genetics and molecular ecology. The classic framework of AMOVA only supports haploid and diploid data, in which the number of hierarchies ranges from two to four. In practice, natural populations can be classified into more hierarchies, and polyploidy is frequently observed in extant species. The ploidy level may even vary within the same species, and/or within the same individual. We generalized the framework of AMOVA such that it can be used for any number of hierarchies and any level of ploidy. Based on this framework, we present four methods to account for data that are multilocus genotypic and allelic phenotypic (with unknown allele dosage). We use simulated datasets and an empirical dataset to evaluate the performance of our framework. We make freely available our methods in a new software package, polygene , which is freely available at https://github.com/huangkang1987/polygene .     

The use of synthetic octoploids in strawberry breeding

Summary A number of methods of producing synthetic octoploids from Fragaria species of lower levels of ploidy are described. Six synthetic octoploids were produced from various combinations involving one hexaploid species, two tetraploid species and four diploid species. Three of the synthetic octoploids are male fertile and were used successfully as male parents in crosses with octoploid strawberry cultivars.