内蒙古不同生态区冷蒿染色体核型观察

以内蒙古不同生态区的冷蒿(Artemisia frigida)为研究对象,采用碱性石碳酸品红染色法和核型分析标准,对冷蒿染色体进行了观察分析.结果表明:冷蒿染色体数目有2n=18和2n=36两种倍性,在冷蒿的原种和变种中均有二倍体和四倍体类型.     

新疆紫草的组织培养及其染色体分析

新疆紫草(Arnebia euchroma)的胚轴、子叶、根都产生愈伤组织。不同来源的外植体产生苗的能力不同,胚轴来源的愈伤组织分化苗最多,而且苗生长旺盛。根的愈伤组织只产生不定根。新疆紫草的核型是 K(2n)=14=2m 8sm 2sm(SAT) 2st。随着继代培养代数增多,染色体变异的种类和频率以及染色体数目显著增加。如果继代培养时间较长,染色体数目变异的范围更广,而且出现染色体结构变异。     

新疆紫草的组织培养及其染色体分析

新疆紫草(Arnebia euchroma)的胚轴、子叶、根都产生愈伤组织。不同来源的外植体产生苗的能力不同,胚轴来源的愈伤组织分化苗最多,而且苗生长旺盛。根的愈伤组织只产生不定根。新疆紫草的核型是K(2n)=14=2m+8sm+2sm(SAT)+2st。随着继代培养代数增 多,染色体变异的种类和频率以及染色体数目显著增加。如果继代培养时间较长,染色体数目变异的范围更广,而且出现染色体结构变异。     

盾叶薯蓣胚乳再生体系的建立及其染色体倍性鉴定

以盾叶薯蓣（Dioscorea zingiberensis）的胚乳为外植体,研究了不同植物生长调节剂对胚乳愈伤组织诱导及植株再生的影响,并鉴定了再生植株。结果表明：愈伤组织诱导形成的适宜培养基为MS＋2.0mg·L^–12,4-D＋0.5mg·L^–16-BA,不定芽分化的适宜培养基为MS＋2.0mg·L^–16-BA＋0.1mg·L^–1NAA,生根的适宜培养基为1/2MS＋0.3mg·L^–1NAA;再生植株炼苗移栽后,成活率可达80%;对获得的再生植株腋芽生长点进行染色体制片观察,发现染色体数目为20的细胞占观察细胞总数的10%,染色体数目为21–29的细胞占16%,染色体数为30的细胞占74%;获得了三倍体植株。     

几个芒果品种的胚性及多胚苗遗传分析

通过目测,筛选出芒果多胚种子,观察其多胚形态;将多胚种子培育成多胚苗,观察其生长发育状况;取多胚苗和母树叶片进行体细胞染色体数目鉴定及同工酶的分析.结果表明,多胚类群的品种中有单胚现象出现,土芒、吕宋、象牙单胚出现的频率分别为1.04%、3.85%和5.44%;土芒和象牙胚数出现的范围分别为2-6和2-8.多胚种子子叶形态和胚轴的着生位置各异.种子多胚的萌发率、成活率及多胚苗的生长状况均与多胚种子的胚数、子叶发育大小等因素相关.多胚苗体细胞染色体数目是2n=40,未发现染色体的数目变异.POD同工酶分析表明,同一种子的多胚苗间酶谱上存在着差异.     

黄麻栽培种圆果种×长果种的种间杂交研究

１９８９—１９９１年对黄麻栽培种圆果种（Ｃｏｒｃｈｏｒｕｓｃａｐｓｕｌａｒｉｓ）和长果种（Ｃ．ｏｌｉｔ－ｏｒｉｕｓ）选用了具有不同茎色和腋芽性状的材料做了６个组合,获得１３４株杂种Ｆ＿１苗。但苗株发根不良,在移栽后两周陆续死亡,最后幸存ＲＲ－５×（ＢＬ×７７－１９）Ｆ＿１组合中两株植株并开花、结果。Ｆ＿１均有腋芽,表现为父本的性状;花果形状偏向母本;茎色红同双亲。这两株的Ｆ＿２,茎色和腋芽性状分离成４种表现型：红茎或青茎有腋芽及红茎或青茎无腋芽。其中红茎有腋芽的生长较快。对种间杂交技术、亲本间的花粉与柱头亲和性、杂交花的胚珠受精情况及染色体构型等方面也作了观察、研究。     

中国西部高山8种龙胆属植物的染色体数目

本文报道了我国西部高山上的８种龙胆属植物的染色体数目。其中宽筒龙胆的染色体数目为２ｎ＝４８,提钟龙胆的染色体数目为２ｎ＝２６,小齿龙胆和四数龙胆的染色体数目为２ｎ＝２４,南山龙胆的染色体数目为２ｎ＝１８,上述５种植物的染色体数目为首次报道,其余蓝玉簪龙胆的染色体数目为２ｎ＝２４,线叶龙胆的染色体数目为２ｎ＝４８,钻叶龙胆的染色体数目为２ｎ＝１８。     

甘蔗健康种苗繁育技术研究进展

甘蔗健康种苗系指通过种茎温汤处理或腋芽茎尖培养等方法脱去甘蔗体内病菌的腋芽试管苗或种茎及其无性繁殖种茎苗,以及在不同隔离条件下逐代繁育并符合标准的原原种、原种和生产用甘蔗种苗。在生产甘蔗健康种苗过程中,利用间歇浸没式生物反应器(TIBs)进行甘蔗健康种苗的快繁,提高了增殖系数,降低了工作量。"甘蔗健康种子"的新技术,大大减少了甘蔗种植的用种量,并有利于机械化操作,降低了甘蔗种植成本。     

减数分裂中染色体不分离与染色体病

人类细胞减数分裂是精卵形成过程中的重要阶段。它包括染色体的一次复制 ,细胞的两次连续的分裂以及同源染色体配对、交换 ,同源染色体分离 ,姐妹染色单体分离等一系列复杂的过程。在细胞分裂进入中、后期时 ,如果其一对同源染色体或两姐妹染色单体未分别向两极移动 ,却同时进入一个子细胞中 ,结果细胞分裂所形成的两个子细胞中 ,一个将因染色体数目增多而形成超二倍体 ,一个则由于染色体数目减少而形成亚二倍体。这一过程称染色体不分离 (ｃｈｒｏｍｏｓｏｍａｌｎｏｎ -ｄｉｓｊｕｎｃｔｉｏｎ) ,从而引起配子中染色体数目异常 ,产生非整…     

染色体倍性的几个重要概念及表示方法

为清楚理解和掌握染色体数目变异的内容,必须弄清有关染色体数目变异的一些重要概念,如染色体组、单倍体与一倍体、Zn、n、x符号的含意等。现将一些概念的确切含意叙述如一F。染色体倍性是指细胞中含的染色体组数,又分整倍性和非整信性,整倍性是指细胞中所含有的染色体组都是完整的染色体组,如单倍体、二倍体、三倍体等。非整倍性是指细胞中所含的染色体组处于不完整状态,一般指二倍体种成对染色体的成员增加了或减少了。在二倍体细胞或个体中,能维持配子正常功能,包括一定数目、形态结构和一定基因组成的一套染色体称为染色体组或…     

Phenotypic Variation and Changes of Chromosome Number in Plantlets Regenerated from Potato Protoplasts

Morphological variation and change of chromosome number in the plantlets of potato (Solanum tuberosum L. cv. Xiao Yie Zi × Duo Zi Bai) regenerated from mesophyll protoplasts have been studied. The normal plantlets from protoplasts were similar to parent plants. Their chromosome numbers were 2n = 48±or 2n= 72 of euploid. The plantlets with distinctive phenotypic variation were likely to be aneuploid with increased chromosome numbers.     

Somatic Embryogenesis and Cytological Variation in Protoplast Culture of Levisticum officinale Koch

Protoplasts were isolated from spongy calli in a well growing state. Protoplasts were induced to undergo sustained divisions and to form colonies in the liquid C81V medium supplemented with 2,4-D and kinetin. When protoplast derived colonies were transferred onto agarsolidified medium, the spongy, white calli developed. After being subcultured on N6 medium plus 6BA and IBA, the light-yellow, granular embryogenic calli emerged on the protoplast regenerated callus surface. A large number of plantlets were obtained on MS medium with NAA and IBA via somatic embryogenesis Cytological observation on the donor calli used for protoplast isolation and plantlets regenerated from protoplasts were carried out. Remarkable variation of nucleus morphology and chromosome numbers were observed in donor calli. However, the cytological abnormalities in plantlets regenerated from protoplasts were comparatively less seen. The reason are discussed.     

Detection of somaclonal variation of cotton (Gossypium hirsutum) using cytogenetics, flow cytometry and molecular markers

Two protocols of plant regeneration for cotton were adopted in this study, namely, 2, 4-D and kinetin hormone combination and IBA and kinetin hormone combination. Twenty-eight embryogenic cell lines via somatic embryogenesis and 67 regenerated plants from these embryogenic calli were selected and used for random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR), chromosomal number counting, and flow cytometric analysis. The roles of RAPD and SSR markers in detecting somaclonal variation of cotton (Gossypium hirsutum L.) were evaluated. Two cluster analyses were performed to express, in the form of dendrograms, the relationships among the hormone combinations and the genetic variability. Both DNA-based techniques were able to amplify all of the cell clones and regenerated plantlets genomes and relative higher genetic variation could be detected in the culture type with 2, 4-D and kinetin hormone combination. The result suggested that 2, 4-D and kinetin hormone combination could induce relative high somaclonal variation and RAPD and SSR markers are useful in detecting somaclonal variation of regenerated cotton plants via somatic embryogenesis. Chromosome number counting and flow cytometry analysis revealed that the number of chromosomes and ploidy levels were nearly stable in all regenerated plants except two regenerated plantlets (lost 4 and 5 chromosomes, respectively) which meant that cytological changes were not correlated with the frequency of RAPD and SSR polymorphisms. This result also might mean that the cell lines with variation of chromosome numbers were difficult to regenerate plants.     

Spontaneous versus colchicine-induced chromosome doubling in maize anther culture

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.     

秋水仙碱诱导甘草四倍体的研究

以胀果甘草成熟种子为材料,消毒后在培养皿中萌动处理12 h、24 h、36 h,用浓度为0.05%、0.075%、0.10%的秋水仙碱处理12 h、24 h、36 h,来进行四倍体的诱导,并对诱导处理后获得的再生植株进行染色体鉴定。结果表明:种子萌动处理24 h后,用浓度为0.075%的秋水仙碱溶液处理24 h诱导效果最好,变异率为41%。其体细胞染色体数目由2n=2x=16变为2n=4x=32。     

红芽芋球茎片两步法离体快繁及其再生苗生理和光合特性研究

以江西铅山红芽芋(Colocasia esculenta L.Schott var.cormosus‘Hongyayu’)试管苗为材料,建立了芋球茎片两步法离体快繁体系,并对其再生苗的形态指标、染色体数目、生理和光合特性以及叶绿素荧光特性进行了检测。结果表明:(1)红芽芋球茎片单芽诱导的最佳培养基为MS+KT 2 mg/L+6-BA 1 mg/L+NAA0.1mg/L,诱导培养30d后将单芽从球茎片上分离,再接种到生根培养基(MS+KT 2mg/L+NAA 0.1mg/L)上培养30d即可形成完整植株,移栽成活率高达98%;(2)由球茎片单芽、丛生芽、不定芽离体快繁获得的红芽芋再生苗在形态指标、叶下表皮气孔参数、染色体数目、生理生化指标以及叶片光合特性参数和叶绿素荧光特性方面均无显著差异。说明红芽芋球茎片两步法离体培养的再生苗繁殖系数高、染色体数目稳定,该离体快繁体系可应用于江西铅山红芽芋的工厂化生产。     

欧当归原生质体培养中体细胞胚胎发生和细胞学变化

从继代培养的欧当归(Levisticum officinale Koch)愈伤组织分离的原生质体在 C81V培养基中培养,得到了较高频率的持续分裂。形成的细胞团转移到固体培养基上后,发展成了白色松软型的愈伤组织。将其转移到附加6-苄氨基嘌呤和吲哚丁酸的 N6培养基上继续培养了2—3个月后,表面出现了浅黄色、颗粒状的胚性愈伤组织。后者在附加吲嗓丁酸和萘乙酸的 MS 培养基上培养,可通过体细胞胚胎发生途径分化出大量小植株。对供体愈伤组织和原生质体再生植株进行了细胞学观察。     

扁茎黄芪同源四倍体的诱导

以扁茎黄芪的干燥成熟种子为试验材料,用0．1％、0．3％和0．5％的秋水仙碱溶液分别浸泡种子24h、48h、72h和96h来诱导同源四倍体,并对诱导处理后获得的再生植株进行染色体鉴定,得出以0．3％秋水仙碱溶液浸泡72h为诱导同源四倍体的最佳处理组合。     

Effect of genotype,explant, subculture interval and environmental conditions on regeneration of shoots from in vitro monoploids of a diploid potato species,Solanum phureja Juz. & Buk.

In vitro anther-derived monoploids (2n=x=12) of Solanum phureja were compared for shoot regeneration from leaf and stem explants under various environmental conditions. Monoploids from the same or different diploid clones varied for frequency and earliness of shoot regeneration and number of shoots formed per explant. Leaf explants regenerated at higher frequencies than stem explants. Explants from stock plantlets subcultured at a 2- or 4-week interval regenerated earlier and at a higher frequency than those from plantlets subcultured at longer intervals. Regeneration frequency and number of shoots per explant were greater when explants were incubated at 20°C compared to 25°C. Explants from stock plantlets maintained under a 16 h as opposed to an 11 h photoperiod exhibited increased shoot regeneration; however, neither photoperiod nor the maintenance temperature of the stock plantlets influenced regeneration frequency. Genotypic differences were observed for the frequency of chromosome doubling among regenerated shoots whereas temperature treatments had no influence on chromosome doubling.Abbreviations BA benzyladenine - GA₃ gibberellic acid - IAA indole-3-acetic acid - NAA -naphthale-neacetic acid     

Ploidy doubling by callus culture of potato dihaploid leaf explants and the variation in regenerated plants

Somatic chromosome doubling of potato dihaploids was achieved by culturing callus from leaf pieces derived from glasshouse and in vitro grown plants. The glasshouse-grown leaves produced better callus on average but there was no significant difference between the average number of plantlets per callus regenerated from the two types of material. Mixtures of 2x and 4x plants were obtained from callus culture and the proportions of each ploidy type varied with the dihaploid genotype. Leaflet length/breadth ratios were chiefly determined but ploidy but there was variation within ploidy groups. There were also differences in blight and cyst nematode resistance between tetraploids derived from the same dihaploid.