秋水仙素浸芽法处理玉米单倍体的加倍效果研究

试验采用28个育种材料的玉米单倍体籽粒,使用0.06%秋水仙素溶液浸泡幼芽上部和幼芽全部,研究秋水仙素对玉米单倍体的加倍效果的影响。结果表明,3年中不同秋水仙素浸芽方法处理玉米单倍体的成活率、授粉率和结实率之间的差异达到显著或极显著水平。浸泡幼芽上部处理能够明显减轻药害,缩短缓苗时间,提高单倍体植株的加倍效果,成活率、授粉率和结实株率均是浸泡幼芽全部处理的1.5倍左右,而且浸泡幼芽上部处理的授粉率和结实率分别是对照的2倍和4倍以上。     

秋水仙素诱导马铃薯野生种S.acaule多倍体的初步研究

马铃薯野生种需通过人工诱导染色体加倍后才能与栽培种进行杂交。本试验以马铃薯野生种S.acaule无菌苗带腋芽茎段为材料,采用浸泡法和混合培养法研究了秋水仙素诱导马铃薯野生种S.acaule产生多倍体的诱导效果。结果表明:在继代增殖培养基中添加浓度为0.3%的秋水仙素,共同培养时间为14d时获得诱导变异率最大,为31.6%;获得的87株变异株有2株为多倍体植株。     

秋水仙素离体诱导大花蕙兰多倍体试验

在离体培养条件下,以大花蕙兰红宝石原球茎为材料,比较了秋水仙素浸泡法和混培法在不同浓度、不同处理时间诱导加倍的效果。结果表明:无论是用秋水仙素溶液浸泡还是将秋水仙素加入培养基中混培,均可诱导大花蕙兰多倍体的产生。但以混培法效果较好,在秋水仙素3%、处理15d的条件下,诱导率最高达30%。     

青檀多倍体诱导试验初报

为获得具有优良性状的青檀四倍体植株,以青檀幼苗为试验材料,通过秋水仙素浸泡生长点的方法,研究了不同秋水仙素浓度和处理时间对青檀染色体加倍的诱导效果。结果表明：以0.4％—0.8％秋水仙素处理72ｈ诱导效果最佳,变异率最高达34.2％。经流式细胞仪和茎尖染色体鉴定,初次镜检青檀四倍体植株染色体数目为2n＝4x＝36,成功获得了青檀四倍体植株。     

白魔芋多倍体诱导研究初报

采用种子浸泡法和根状茎顶芽滴液法进行白魔芋多倍体诱导，比较了不同秋水仙素浓度和不同处理时间对出苗率和变异率的影响。结果表明，滴液法对材料的毒害性更小，经同一浓度秋水仙素溶液处理后出苗率和植株形态变异率均高于种子浸泡法，但诱变加倍的效果不如浸泡法。实验中获得一株纯合四倍体植株，由0.20%秋水仙素溶液处理种子48h诱变得到。     

秋水仙素浓度、浸苗时间对烟草单倍体幼苗的加倍效应研究

为了提高烟草单倍体植株的染色体加倍率,采用二次饱和D-最优设计,以两片真叶期的烟草单倍体幼苗为材料,研究了秋水仙素浓度及其浸苗处理时间对染色体加倍的效应.结果表明,随着秋水仙素浓度的提高,加倍率呈开口向下的抛物线曲线变化趋势;加倍率与浸苗时间呈线性回归关系,加倍率随浸苗时间的延长而增加;0.346 9%的秋水仙素、浸苗72 h是烟草单倍体幼苗染色体加倍率最高(达54.18%)的最佳处理组合.     

秋水仙素诱导乌拉尔甘草同源四倍体的研究

在组织培养条件下,用秋水仙素溶液浸泡乌拉尔甘草试管苗(2n=2X=16)茎尖进行同源四倍体诱导,比较了不同秋水仙素浓度和不同处理时间对存活率、变异率的影响,并对加倍植株的鉴定和纯合四倍体的分离方法进行了研究.结果表明,秋水仙素浓度为0.1%,浸泡时间为12h时,茎尖的存活率和变异率分别为52.3%和22.1%,诱导率较高,并通过保卫细胞和根尖染色体数目鉴定,成功获得了甘草同源四倍体(2n=4X=32),为开展甘草多倍体育种奠定了物质和技术基础.     

东北生态区玉米单倍体浸芽加倍效果的初探

以高诱1号诱导的玉米单倍体子粒为材料,采用秋水仙素浸芽的方法进行人工加倍。结果表明:秋水仙素浓度、浸芽的温度和浸芽时间对玉米单倍体加倍有明显的影响,且差异达极显著水平。0.05%秋水仙素和5%二甲基甲砜混合药剂在15℃下浸泡9h,单倍体的加倍效果最好,加倍率可达38.1%。     

半浸根法加倍小麦远缘杂交幼胚再生植株染色体

染色体加倍是小麦单倍体育种和克服远缘杂种不育的重要技术之一.多年来,应用秋水仙素对花培产生的单倍体植株的染色体加倍进行了大量研究[1～4],但对小麦远缘杂交幼胚再生植株的染色体加倍技术研究很少.传统的全浸根法染色体加倍技术成功率低,而且死苗严重.和现昌等[5]用半浸根法就地挖坑加倍小麦花粉植株,加倍率达80%以上,幼     

球茎大麦在大麦育种上的应用——Ⅰ.大麦单倍体的诱导与加倍单倍体的产生

以三种栽培大麦品种为母本,三种球茎大麦为父本进行杂交。诱导栽培大麦单倍体,结果杂交成胚率平均为47.9％,幼胚离体培养成苗率平均为54.0％。这些胚培苗的根尖细胞染色体数目分别含有7,14,21条,不同组合杂交后代含有的染色体数目不同,所有含有7条染色体的后代,其染色体C-带带型显示为父本栽培大麦的染色体,表明该后代为栽培大麦单倍体,用滴加0.04％秋水仙素的Knop溶液进行单倍体植株的染色体加倍,结果加倍率达90％以上,另外,我们还讨论了染色体消失法诱导单倍体的优越性及其机理。     

开发实用的染色体加倍体系构建成烟草DH群体

通过对4种染色体加倍方法(烟草浸花药法、浸花培苗法,叶片再生法及浸腋芽法等)的比较研究表明：以4g／L浓度的秋水仙碱浸泡花药法加倍率最高达47．5％～75％,其次为叶片再生法(30％～36．67％)和浸苗法(16．67％～32．35％),而浸腋芽法较低(17．78％)。前两种方法加倍率虽高,但有较高畸形苗比率,叶片再生法工序较繁琐。作者认为烟草加倍单倍体产生,应以采用浸苗法为主。在使用秋水仙碱浸苗加倍时,添加DMSO可明显促进秋水仙碱的加倍效率,且促进作用随时间延长而提高：从高效、快捷和节约等原则考虑,我们开发了烟草有效的染色体加倍体系,以4g／L的秋水仙碱 20g／LDMSO溶液浸苗48h的效果最好。对两个组合烟草单倍体苗浸12h以上,其染色体加倍效率达到对照的2．30-2．93倍。本试验用较低浓度秋水仙碱添加DMSO有利于节约实验费用。通过完善染色体加倍技术程序已构建成2个DH群体,供基因定位研究。     

人工诱变芦荟多倍体的初步研究

以秋水仙索为诱变剂，利用茎段浸泡和秋水仙素培养基2种方法对库拉索芦荟进行诱变，结果表明，茎段浸泡秋水仙素法诱导四倍体葡萄的效果优于秋水仙素培养基法，0．2％的秋水仙素处理4d变异效果最好，诱变率达到最高值41.5％。变异株叶片肥厚，叶色深绿，叶片表皮气孔保卫细胞中叶绿体数增多。     

The effect of colchicine on triticale anther-derived plants: Microspore pre-treatment and haploid-plant treatment using a hydroponic recovery system

In cereals, chromosome doubling of microspore-derived haploid plants is a critical step in producing doubled haploid plants. This investigation was undertaken to study the effect of incorporation of colchicine in the induction medium for anther culture, and the effect of colchicine on anther culture-derived plants of triticale grown under controlled greenhouse conditions. In the latter case, chromosome doubling of adult sterile plants derived from anther culture of fourteen triticale populations was attempted, where androgenetic plants with non-dehiscent anthers were cloned and subjected to the colchicine treatment, and then grown with the aid of hydroponics. The hydroponic system provided optimal conditions for recovery of the affected haploids from the toxic effects of colchicine treatment and all colchicine-treated plants survived. A topcross-F₁ (TC₁F₁) population with timopheevii cytoplasm produced the highest percentage of plants with seed-set either due to chromosome doubling by colchicine (98%) or spontaneous doubling of chromosome number (15%). Colchicine-treated anthers performed inferior than control in both induction and regeneration phases. One of the key observation of this study was the reversal from reproductive stage back to the vegetative stage which in turn enabled further cloning of haploid plants under hydroponic conditions once they were identified as sterile. The one hundred percent survival rate of in vitro-derived plants, 100% survival rate of colchicine treated haploid plants and the high chromosome doubling success rate (X = 82.3) observed in this study imply that a temperature-controlled greenhouse with an hydroponic system provides an efficient environment for inducing chromosome doubling of haploid plants in cereals. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effective Diploidization of Microspore-Derived Haploids of Rape (Brassica napus L.) by In Vitro Colchicine Treatment

A technique for the in vitro colchicine treatment of microspore-derived haploids of rape (Brassica napus L.) is presented. This allows effective and time-saving chromosome doubling. The most effective method consists of an application of 50 mg/1 colchicine in a liquid B5 medium to the rooted micro-spore-derived plantlets for 4–8 days. By this treatment more than 50 % of the plants developed at least diploid sectors. A change of medium after some days may even increase this diploidization rate.     

Genetic and environmental effects on chromosome doubling of sugarbeet (Beta vulgaris L.) haploids

Summary Chromosome doubling has been a limiting factor for production of doubled-haploids, a means of obtaining fruly homozygous individuals, and a time-saving alternative to repeated selfing for the creation of inbred lines. The existence of genetic, environmental and genotype × environment interaction effects on chromosome doubling ability of sugarbeet (Beta vulgaris L.) haploids was investigated. Haploids were derived from four distinct, highly heterozygous diploid populations through in vitro culture of unpollinated ovules. Ovule-derived plants were treated with colchicine to double their chromosome complement. Environmental effects were determined from replication of the experiment at seven dates. Both genetic and environmental factors were found to affect chromosome doubling ability of sugarbeet haploids. No significant interaction between genotype and environment was identified. The presence of genetic effects on chromosome doubling ability is discussed with regard to its implications on breeding programs.     

Development of novel chromosome doubling strategies for wheat × maize system of wheat haploid production

Two chromosome doubling strategies were evaluated for producing wheat doubled haploids from wheat x maize crosses: (i) in vitro colchicine application to haploid embryos and (ii) colchicine treatment through postpollination tiller injections. In the in vitro approach the haploid embryos were rescued on medium containing colchicine (at concentrations of 0.2, 0.3, 0.4 and 0.5%) and moved to a colchicine‐free regeneration medium 48 h later. Embryos exposed to 0.5% colchicine had 91.67% of their regenerated plants showing chromosome doubling. In the tiller injection approach, different concentrations (0.5, 0.75 and 1.0%) of colchicine solution, which also contained 2,4‐D (100 ppm), were injected into the uppermost inter‐node of crossed tillers 48 and 72 h after pollination. The chromosome doubling efficiency varied from 33 to 100%, with 1% treatment being the most effective. No chimeras of doubled/haploid sectors were observed in the case of the tiller injection treatment and all the florets showed seed set in the doubled plants. Stomatal guard cell length provided rapid, early‐stage and unambiguous analysis of ploidy level on the basis of 10 guard cell observations per plant.     

The production of homozygous diploid plants of Solanum verrucosum by tissue culture techniques

Summary Monohaploid plants of S. verrucosum (2n=x=12) were induced in anther culture. Axillary buds from these plants were treated with colchicine in shoot tip culture for 48 hours and then transferred to a colchicine free medium. The resulting plantlets were scored for diploidy by stomatal chloroplast counts and root tip cytology and it was found that doubling of the chromosome number had occurred.     

秋水仙素诱导蚕豆及玉米根尖细胞染色体变异的研究

为进一步了解秋水仙素对农作物根尖细胞染色体畸变的遗传毒害效应,以地方品种敏感型绿皮小粒蚕豆和饲用玉米为材料,研究不同浓度秋水仙素（0、0.01%、0.05%、0.10%、0.15%、0.20%）及不同培养时间（24、48、72h）对2种作物染色体的畸变影响。结果表明：秋水仙素能诱发根尖膨大,当秋水仙素浓度为0.20%处理24h,蚕豆根尖膨大率100%;秋水仙素浓度为0.20%处理72h,玉米根尖膨大率65.8%;适当浓度秋水仙素（0.01%、0.05%）可促进蚕豆和玉米根尖细胞的有丝分裂,当浓度≥0.10%,反而抑制蚕豆和玉米细胞分裂。在染色体畸变类型中,微核最多,其次是染色体断片,最少是染色体桥。秋水仙素浓度0.20%,处理时间72h,蚕豆畸变率和玉米畸变率均最高,分别为11.92%和7.25%;秋水仙素浓度0.10%,处理时间72h,蚕豆染色体加倍指数最高为7.97%;秋水仙素浓度0.20%,处理时间24h,玉米细胞加倍指数最高为4.64%。     

马铃薯高效染色体加倍方法建立与抗寒资源创制

In this work, different treatment combinations including colchicine concentrations and treatment methods as well as different time points was used to investigate the survival rate and chromosome doubling efficiency of potato tissue culture plantlets. The potato chromosome doubling by using colchicine had been successfully optimized. The potato plantlet stems treated with 0.1% colchicine for three days shaking at 120 r min^-1 showed the highest doubling efficiency due to its better contact to the colchicine solution. Compared with other potato chromosome doubling techniques, this method has much higher chromosome doubling rate, shorter time treatment and easier to operate, so that it could provide a higher efficient method for potato ploidy operation. In the meantime, compared with the diploid, the tetraploid interspecific hybrids showed differences in the morphological characteristic, which had higher plants, thicker stem, bigger petals and pollen grain. In addition, no significant difference was found between diploid and tetraploid interspecific hybrids in terms of cold resistance, but both significantly enhanced cold resistance compared with the common potato cultivar. Taken together, the doubled interspecific hybrids could sever for improving cold resistance of potato cultivars.