迎阳报春四倍体诱导及鉴定

在离体培养条件下,研究了秋水仙素溶液处理对迎阳报春愈伤组织分化和多倍体诱导的效应。结果表明,秋水仙素处理明显抑制愈伤组织的分化,使死亡率增加;在试验浓度和时间范围内,以30mg·L-1秋水仙素溶液处理愈伤组织10d,四倍体诱导率最高,为23.08%;四倍体植株与二倍体植株相比,其气孔变大,且叶片变厚、变大,叶色浓绿、株型紧凑;二倍体植株染色体2n=2x=24,四倍体植株染色体2n=4x=48。     

秋水仙素诱导青岛百合四倍体研究

以青岛百合试管苗为试验材料,采用浸泡法和混培法研究了秋水仙素对青岛百合进行染色体加倍的诱导效果。结果表明:以0.05 %的秋水仙素浸泡处理24h的诱导效果最佳,诱导频率高达53.3%;经秋水仙素诱导的多倍体与正常二倍体植株比较,植株叶片变大,根系粗壮,气孔显著增大而单位面积气孔数减少。对变异材料的细胞学研究发现, 四倍体植株的染色体数目为2n=4x=48。     

黑果枸杞多倍体诱导及鉴定

为了建立黑果枸杞多倍体诱导方法及快速、准确和高效的多倍体鉴定技术,以黑果枸杞二倍体种子经浸泡后的吸胀种子与萌动种子为材料,用不同浓度的秋水仙素进行不同时间的诱导处理,通过流式细胞仪测定细胞核DNA含量的方法对诱导后的植株进行倍性鉴定,并与传统的染色体计数、气孔密度和大小测定、叶绿素相对含量测定等不同方法进行比较。结果表明,0.1%的秋水仙素(内含2%的DMSO)可有效地诱导黑果枸杞萌动种子的染色体加倍,其中24 h处理的效果最好,诱导率为33.3%。经流式细胞仪细胞核DNA含量测定以及压片染色体计数等方法鉴定,获得的多倍体有四倍体、八倍体。在形态上,多倍体植株具有叶色深绿,叶脆,易折断,叶片加厚、卷曲,叶下表皮气孔增大,密度减少等特征。本研究建立的黑果枸杞多倍体诱导方法以及利用流式细胞仪进行细胞核DNA含量测定分析植株倍性技术可方便快速的培育出黑果枸杞多倍体植株,为黑果枸杞新品种选育提供参考。     

秋水仙素诱导地锦多倍体研究

用不同浓度秋水仙素处理不同萌发时期地锦体细胞胚胎及丛生芽苗诱导多倍体,对多倍体植株进行染色体数目及稳定性检测。结果表明:(1)秋水仙素对地锦体胚及丛生芽的生长有不同程度抑制作用,对根系生长的抑制尤为明显。以0.05%秋水仙素处理48h以上对地锦体胚萌发有显著抑制作用,0.1%浓度处理96h产生完全抑制。(2)0.05%秋水仙素处理1cm体胚48h可诱导3.3%地锦体胚产生多倍体嵌合植株,多倍细胞比率40%。以0.1%秋水仙素处理地锦丛生芽24h,多倍体诱导率可达13.3%,多倍细胞比率62.5%~75%。说明秋水仙素处理丛生芽效果要好于处理体胚。(3)本实验诱导的多倍体植株全为混倍体,多倍细胞占40%~75%,但在无性增殖中有逐代下降趋势。(4)多倍体植株中出现4裂和5裂叶片的变异体。     

二甲戊灵与秋水仙素离体诱导虎眼万年青多倍体发生的比较研究

以白花虎眼万年青(Ornithogalum thyrsoides)组培的丛生芽(2n=2x=12)为试验材料,采用溶液浸泡法,研究秋水仙素和二甲戊灵的不同浓度和处理时间对白花虎眼万年青多倍体的诱导效果,观察根尖细胞染色体数,叶片下表皮保卫细胞及叶片组织结构特征。结果表明:800μmol·L-1二甲戊灵浸泡24h,变异率达46.67%,0.05%秋水仙素处理48h,达42.22%,两种诱变剂诱导变异的差异虽不显著,但前者处理后材料存活率高于后者(前86.67%,后80.0%)。对变异的材料通过细胞学鉴定,发现两种诱变剂均能诱导出四倍体白花虎眼万年青。从处理时间短,材料死亡率低,对人畜伤害小,成本低,变异率较高以及两种诱变剂处理得到的多倍体气孔、叶片结构特征的相似性等综合条件考虑,可将二甲戊灵作为秋水仙素的替代品诱导多倍体。此外,对比二倍体与四倍体植株形态特征、叶片下表皮气孔数目及大小,可将气孔大小作为初步快速检测多倍体的有效方法。本试验用2种诱变剂诱导白花虎万年青多倍体,并从形态、气孔、叶片组织结构比较诱导前后差异,旨在为白花虎眼万青年多倍体新品种研究提供数据支持。     

基于悬浮细胞培养的半夏多倍体诱导研究：Ⅱ.单细胞水平COLO诱导及多倍体植株再生

在建立了高效的半夏悬浮细胞培养和植株再生体系的基础上,本研究以悬浮细胞作为靶标材料,以秋水仙素（COLO）为多倍体诱导剂,对COLO诱导多倍体的适宜浓度等关键因素进行研究,并在获得多倍性细胞后,经诱导分化和再生形成纯合的多倍体植株。结果显示,0.05～0.10mg/ml的COLO处理24h,可获得较好的多倍体细胞诱导效...     

秋水仙素诱导兰考泡桐同源四倍体

在含不同浓度秋水仙素的MS+0.1mg/L NAA+15mg/L BA(最适器官发生)双层培养基上进行兰考泡桐四倍体植株诱导试验,并通过变异植株根尖细胞染色体观察和叶片单细胞DNA含量测定进行倍性分析。结果表明,预培养12d的兰考泡桐叶片在秋水仙素浓度为10mg/L的双层培养基上预培养处理24h时,四倍体诱导率最高达到23.4%。变异植株叶片比二倍体大,叶片长宽比变小,叶片单个气孔变大,气孔密度变小。     

秋水仙素诱导杂交兰四倍体及倍性鉴定

以杂交兰F1代无菌苗(2n=2x=40)为供试材料,分别用浓度为0.02%、0.05%、0.10%和0.20%的秋水仙素对其根状茎处理24、48和72h,成功获得了四倍体植株。试验结果表明,以0.10%的秋水仙素处理48h诱导效果最佳,变异率为36%。根尖染色体压片表明,四倍体染色体数为2n=4x=80,二倍体对照为2n=2x=40。加倍后的植株较二倍体植株粗壮,叶片变厚,颜色变深,茎基部粗壮,颜色深,生长势变缓,根系变粗,根状茎增粗,可作为新材料加以利用。     

秋水仙素诱导石斛多倍体的初步研究

本实验以秋水仙素为诱导剂,对石斛杂交种Dendrobium utopia ‘Messenger’×Den. whiterabbit ‘Sakurahime’的二倍体试管苗进行了多倍体诱导、细胞学观察及染色体鉴定等研究。结果表明,当秋水仙素浓度为0.4 ~0.6mg/L时石斛的诱导率较高,最高时可达62.2%。变异植株的叶片变短变厚,假鳞茎明显增粗。在显微镜下观察到变异株的气孔长度和宽度约增加21.44%和28.30%,保卫细胞的长度和宽度约增加30.88%和24.98%。     

彩色马蹄莲2n花粉诱导及其三倍体植株的获得

2n配子介导的有性多倍化因其具有染色体重组创造新型变异的机会而越来越受到育种家的重视.本研究用化学试剂秋水仙素处理彩色马蹄莲(coloured Zantedeschia hybrid)二倍体栽培种幼蕾诱导2n配子,并对2n配子形成的细胞学特征进行了显微观察.结果显示,秋水仙素处理可以诱导彩色马蹄莲2n花粉产生,2n花粉的花粉粒明显变大,适宜的秋水仙素处理浓度为0.15％;配子形成过程中出现平行、融合等纺锤体定位异常现象,四分体时期出现二分体、三分体,产生减数分裂异常的多核细胞、小孢子形成过程中核融合等异常现象;诱导的2n花粉与正常1n雌配子杂交,杂交后代经染色体鉴定筛选获得三倍体后代(2n=3x=48).本研究结果表明,人工诱导2n花粉是培育彩色马蹄莲有性多倍体的一种有效可行的方法.     

秋水仙碱诱导粗皮桉花粉染色体加倍研究

目前自然界仍未发现天然多倍体桉树的存在,建立人工诱导桉树未减数2n花粉技术体系对于推进桉树的多倍体种质创制及遗传改良的意义重大。本研究以粗皮桉为对象,探究其花蕾发育与小孢子母细胞减数分裂进程的特点,并对不同发育阶段花蕾施加秋水仙碱处理,诱导粗皮桉花粉染色体加倍。结果表明,待观察到小孢子母细胞减数分裂开始后48 h,即处于细线期至粗线期的花蕾占比最高时,在靠近花序位置的花枝上切口并导入0.5%浓度的秋水仙碱溶液处理6 h的效果最佳,人工诱导2n花粉的有效诱导率达到31.34%。诱导获得的粗皮桉2n花粉较普通单倍性花粉的形态差异显著。本研究揭示了粗皮桉花蕾发育与小孢子母细胞减数分裂的时序性关系,建立了基于花蕾着生位置和发育时数,即时判别粗皮桉小孢子母细胞减数分裂时期的方法,明确了采用秋水仙碱溶液处理诱导粗皮桉花粉染色体加倍的最佳时机和处理条件,为进一步开展桉树多倍体种质创新工作奠定了重要基础。     

Why no tetraploid cultivar of foxtail millet?

Autotetraploid material was induced by colchicine treatment of a pure line of foxtail millet and an interspecific hybrid between foxtail millet and giant green foxtail. Compared with diploid material, tetraploids were smaller, flowered later, and had a two-fold reduced fertility (number of grain per cm of spike). Grain weight increased by 20% with polyploidy, but total grain yield decreased by 46%. This work illustrates the difficulty of breeding polyploid lines of foxtail millet that are of agronomic use.     

秋水仙素诱导大蒜四倍体的研究

用5种不同浓度的秋水仙素处理大蒜花苞气生鳞茎进行多倍体诱导,发现在固体培养基上接种处理时毒害作用较小,四倍体的诱导率最高能达到66.7%。而液体培养基浸泡处理的毒害作用较大,适宜进行高浓度短时间处理。添加1.5%二甲基亚砜和25℃的温度有利于四倍体大蒜的诱导。细胞水平的证据表明,经过秋水仙素诱导处理得到了大蒜四倍体植株。     

Studies on awns in polyploid rice (Oryza sativa L.) and preliminary cross experiments of a special awnless tetraploid rice

Awns are an important genetic character of rice (Oryza sativa L.) and almost all awnless diploid varieties will change into awned varieties after polyploidization. In order to increase the understanding of awns and promote the development of polyploid rice breeding, the effect of polyploidization on awns was investigated and the development and distribution characteristics have been summarized. Furthermore, cross experiments were made between a special awnless tetraploid rice and two awned tetraploid rice. The results showed that the awns of polyploid rice initially emerged at the pistil–stamina formation stage and there was a stable corresponding relationship between awn development and other organs or development characteristics. Polyploidization had a great effect on awns. Awn length was considerably affected when diploid rice was doubled to polyploid. However, the degree of change varied between varieties. The F₁ hybrids between awnless and awned tetraploid rice in this research were all partial awn types and showed that the larger the mean, maximum awn length and the percentage of awned spikelets (PAS) of their awned parents, then the larger these of their F₁ hybrids. But different cross combinations showed some variation. The F₂ generations were still all partially awned and awnless type was not found. And the awn length and PAS of the plants developing from awned grains were significantly greater than that of the plants developing from awnless ones. This showed that the awn character of a grain could affect the plants developing from this grain. The results laid the foundation of further research of awn inheritance.     

Complete chloroplast DNA sequences of Georgian indigenous polyploid wheats (<Emphasis Type="Italic">Triticum</Emphasis> spp.) and B plasmon evolution

Three types of plasmon (A, B and G) are present for genus Triticum. Plasmon B is detected in polyploid species - Triticum turgidum L. and Triticum aestivum L. By now, 21 complete sequences of chloroplast DNA of the genus Triticum is published by different authors. Many inaccuracies can be detected in the sequenced chloroplast DNAs. Therefore, we found it necessary to study of plasmon B evolution to use only those sequences obtained by our method in our laboratory. Complete nucleotide sequences of chloroplast DNA of 11 representatives of Georgian wheat polyploid species were determined. Chloroplast DNA sequencing was performed on an Illumina MiSeq platform. Chloroplast DNA molecules were assembled using the SOAPdenovo computer program. Using T. aestivum L. subsp. macha var. palaeocolchicum as a reference, 5 SNPs were identified in chloroplast DNA of Georgian indigenous polyploid wheats. 38 and 56 bp inversions were observed in paleocolchicum subspecies. The phylogeny tree shows that subspecies macha, durum, carthlicum and palaeocolchicum occupy different positions. According the simplified scheme based on SNP and indel data the ancestral, female parent of all studied polyploid wheats is an unknown X predecesor, from which four lines were formed.     

The nature of eurytopy in polyploid earthworm species in relation to their use in biological soil amelioration

Summary Many of the most widely distributed species of Lumbricidae are polyploid. So far polyploid forms have been found to be distributed more widely than diploid ones. Taking Eisenia nordenskioldi as an example, it was shown that polyploids are able to occupy new ecological niches within the area of the diploid form. Ecological differences observed in representatives of different chromosomal races provide polyploids with the chance to coexist in one biocurrent, occupying different ecological niches.Dedicated to the late Prof. Dr. M.S. Ghilarov     

Molecular characterization of a novel waxy allele (Wx-A u 1a) from Triticum urartu Thum. ex Gandil.

Granule Bound Starch Synthase I, or waxy protein, is the sole enzyme responsible for the accumulation of amylose during the development of starch granules in wheat. The full coding region of the waxy (Wx) gene was sequenced in Triticum urartu, (a wild diploid species) and is related to the A genome of polyploid wheats. The Wx gene of T. urartu (Wx-A ^u 1) showed a homology of ~88.0?% with Wx-A1 from polyploid wheats. A greater homology was found with Wx-A ^m 1 from the diploid cultivated wheat einkorn. Most of the differences were found in introns although several changes were also detected in exons that led to amino acid changes in the transit peptide and mature protein. These results show the potential of T. urartu as a source of new alleles that could be used in the breeding of durum and common wheat in order to synthesize starches with different properties.