甘薯同一不亲和群内品种间体细胞杂种

利用PEG融合方法,融合甘薯(Ipomoea batatas ) B不亲和群内品种‘koganesengan’和‘bitambi’的原生质体。将融合处理的原生质体进行培养,共获得45株再生植株。4株再生植株形态上表现出融合双亲的中间特性,其中2株染色体数为融合两亲之和（2n = 12x (2n + 2n) = 180）,另外2株分别为41～103和35～100,因细胞不同而不同。经RAPD分析,这4株再生植株分别具有双亲特异的DNA扩增带或双亲都不具有的新扩增带。鉴定这4株再生植株为杂交不亲和的B群内品种间体细胞杂种。     

柑橘与枳属间体细胞杂种再生及其对脚腐病抗性的评价

Page橘柚 (CitrusreticulataBlanco×C .paradisiMacf.)胚性细胞悬浮系原生质体与枳 (Poncirustrifoliata (L .)Raf.)叶肉原生质体经电场诱导融合 ,4～ 5个月再生 15 0余棵小植株。再生植株根系发达 ,叶片具三叶特征。随机检查 2 0余株再生苗根尖染色体数目 ,表明都为四倍体 (2n =4x =36 )。随机取 7株进行RAPD分析 ,表明被检测植株都为杂种。用引起脚腐病的寄生疫霉菌 (PhytophthoraparasiticaDastar)毒素接种体细胞杂种及双亲叶片 ,结果表明 ,Page橘柚中度感病 ,枳高抗 ,体细胞杂种为抗病类型。     

甘薯同一不亲和群内品种间体细胞杂种

利用PEG融合方法,融合甘薯(Ipomoea batatas)B不亲和群内品种‘koganesengan'和‘bitambi'的原生质体.将融合处理的原生质体进行培养,共获得45株再生植株.4株再生植株形态上表现出融合双亲的中间特性,其中2株染色体数为融合两亲之和(2n=12x(2n 2n)=180),另外2株分别为41～103和35～100,因细胞不同而不同.经RAPD分析,这4株再生植株分别具有双亲特异的DNA扩增带或双亲都不具有的新扩增带.鉴定这4株再生植株为杂交不亲和的B群内品种间体细胞杂种.     

粉兰烟草原生质体再生植株

原生质体培养成再生植株是植物休细胞杂 交的关键环节。烟草是原生质体培养和体细胞 杂交的常用材料。烟草属的几个种已能成功地 由原生质体培养成再生植株。野生的粉兰烟草 (N. glazsca)由于具有染色体数目（2n一24）比 普通烟草（2n=48）少的优点,并已成功地被 用车体细胞杂交的亲木之一^[3,4]。本文介绍粉兰 烟草从原生质体游离到植株再生的实验结果。     

水稻原生质体再生植株及后代的性状表现

获得了粳型水稻77-170品系原生质体再生植株(R_2)6个株系的206棵后代植株。对其中96株进行性状观察和细胞学染色体鉴定,发现再生植株子代在株高、剑叶和主穗长、单株有效穗数、每穗粒数、育性、生育期等性状上都产生了变异,除株高外其他性状在第2代遗传上不稳定,染色体倍性稳定(2_n=24)。对56株再生植株子代作酯酶、过氧化物酶同工酶测定,其酶谱谱带与对照实生株相似。     

小麦再生植株的变异研究 Ⅱ.再生植株当代(R_1代)的细胞学和形态学变异

再生植株具有高频率的染色体异常,其中有20.61％表现为染色体数量变异,最常见的为2n—1类型,其次为2n—2类型,也有2n 1、2n—3个体以及染色体数嵌合株。再生植株减数分裂各期均有染色体异常行为,可以见到的有落后染色体、染色体桥、断片、二分体延迟、微核,还有粗线期十字型配对等结构变异,以及五分体、六分体和畸型四分体等异常现象。微核率随培养时间延长而增加,可用作染色体伤害的一个指标。再生植株R_1代存在着许多形态学变异。性状变异与染色体数目变异没有明显关系。     

小麦×冰草属间杂种F_1的植株再生及其变异

在对0.5—40.cm长幼穗培养4周后诱导出愈伤组织的基础上,获得了88株普通小麦(Triticum aestivum cv.Chinese Spring,2n=6x=42,AABBDD)×沙生冰草(Agropyron desertorum Fisch.> Schult.,2n=4x=28,PPPP)杂种F_1的再生植株。不同长度的幼穗在培养时,其愈伤组织发生的部位及其增殖速度不同。再生植株的产生主要是通过直接器官发生途径。所有的再生植株染色体数目全与杂种F_1相同,为2n=35。与杂种F_1相比,再生植株的减数分裂行为是相当复杂的,证明有染色体结构变异的发生。每茎穗数、叶片失绿斑等形态上的变异是由环境效应引起的;而株高、每穗轴节上小穗数和育性是由遗传效应决定的。特别值得注意的是,再生植株的自交结实率高达5.49%,共获得自交种子484粒,这对利用P染色体组中的期望基因有着极为重要的意义。     

白菜与甘蓝之间体细胞杂交种获得与遗传特性鉴定

为拓宽白菜育种的基因资源,改良白菜品质,以白菜(Brassica campestris,2n=20,AA)和甘蓝(B.oleracea L.var.capitata,2n=18,CC)的子叶和下胚轴为材料分离、制备原生质体。采用40%聚乙二醇(Polyethylene glycol,PEG)进行原生质体融合。融合细胞在以0.3 mol/L蔗糖、0.3 mol/L葡萄糖为渗透稳定剂,附加1.0 mg/L 2,4-D+0.5 mg/L 6-苄氨基嘌呤(6-BA)+0.1 mg/L 1-萘乙酸(NAA)+1.0 mg/L激动素(Kinetin,Kin)的改良K8p培养基中培养并诱导细胞分裂。小愈伤组织经增殖培养后在MS+0.2 mg/L玉米素(Zeatin,ZEA)+1 mg/L 6-BA+0.5 mg/L Kin+0.4 mg/L NAA的固体分化培养基上诱导出不定芽。30 d后再转入MS基本培养基,获得完整的再生植株。将生根的植株转移到花盆,并对其杂种性质进行形态学、细胞学和分子生物学鉴定。结果表明,经细胞融合分裂出的320个愈伤组织中,获得了35棵再生植株,其再生率达10.94%。形态学观察显示,绝大多数再生植株的叶面积较大,株型和叶型为两种杂交亲本的中间型,部分植株的叶片浓绿、肥厚。染色体计数结果显示,36.4%的再生植株染色体数为2n=38;36.4%的再生植株的染色体数为2n=58 60;27.2%的再生植株的染色体数为2n=70 76,超过两个融合亲本的染色体数的总和。流式细胞仪测定DNA含量显示,再生植株DNA含量变化比较大,其结果与染色体鉴定结果相吻合。随机扩增多态性DNA(Randomamplified polymorphic DNA,RAPD)和基因组原位杂交(Genomic in situ hybridization,GISH)分析结果证明再生植株具有双亲基因组。体细胞杂种花粉育性比较低,杂交、回交后其育性逐渐获得恢复,与白菜回交后代逐渐恢复了育性。通过体细胞杂交和回交、杂交获得了形态变化广泛的个体,为白菜的品种育种提供多样的种质资源。     

Ogura CMS紫菜苔×萝卜×甘蓝型油菜杂种的获得及细胞遗传学研究

以OguraCMS紫菜苔×萝卜杂种F1(AR ,2n =19)为母本 ,以甘蓝型油菜 (AACC ,2n =38)为父本进行杂交 ,获得了 4棵杂种植株。其中 1株 (PRN 1)的花色为嵌合体 ,该植株上的花多为黄色 ,但是也有乳白色花 ,另外还有 1朵花甚至 1个花瓣上同时具有黄色和白色区域 ,其余 3株 (PRN 2、 3、 4 )都开白花。PRN 4的花药开花前退化 ,其余 3株都可以看到 3～ 6枚花药 ,能够产生部分花粉 ,但是PRN 2的花粉不能被I2 KI溶液染色。PRN 2具有 4个蜜腺 ,PRN 1和PRN 3具有 2个蜜腺 ,PRN 4无可见蜜腺。在低温下PRN 2叶色正常 ,其余 3株幼叶表现不同程度缺绿。PRN 1的染色体数目为 2n =38,染色体平均配对构型为 14 6 7Ⅰ +10 0 7Ⅱ +1 0 6Ⅲ ,其染色体组构成可能是AACR ;PRN 2的染色体数目为 2n =35 ,染色体平均配对构型为 13 89Ⅰ +8 33Ⅱ +1 33Ⅲ +0 11Ⅳ ,PRN 3的染色体数目为2n =33,染色体平均配对构型为 14 0 0Ⅰ +7 82Ⅱ +1 0 0Ⅲ +0 0 9Ⅳ。PRN 4的染色体数目未能确定。与甘蓝型油菜回交后PRN 1～ 3植株各自产生了一定数量的种子 ,而PRN 4则未产生种子。对这些杂种及其后代的遗传及育种意义进行了讨论     

中间锦鸡儿(caranaga intermedia)染色体变异研究

对中间锦鸡儿(caranaga intermedia)种子根尖染色体进行检测,统计分析了染色体数目和结构变异类型.核型分析结果表明中间锦鸡儿正常核型为2n=2x=16=14m+2sm,还发现了核型公式为2n=2x=16+1B=1st+9m+2sm+1m(sAT)+1sm(SAT)+2m(SAT)+1B;核型公式为2n=2x=16+1B=6sm+8m+2m(SAT)+IB;以及核型公式为2n=2x=15=7sm+8m的变异类型.本研究首次发现了中间锦鸡儿存在B染色体和中间随体,此外还发现存在单体植株.随体具有个体差异,有中间随体和端部随体两种,且无论个体间和个体内B染色体均存在数目和结构的多态性.对其中120粒种子根尖染色体结果统计分析.发现具有15条染色体的植株占0.83%;具有16条染色体的植株占89.17%;具有17条染色体的植株占3.3%;具有18条染色体的植株占2,5%,其中有一个体中多于的一条染色体始终呈点状;19条染色体的植株占1.67%,5条多于染色体的占0.83%,而多余染色体条数在1～3之间变动的植株占1.67%.     

Somaclonal Variation in Chromosome Number and Nuclei Number of Regenerated Plants from Protoplasts of Actinidia eriantha

By counting the chromosome number of root tip cells in 18 regenerated plants derived from protoplasts of Actinidia eriantha Benth., the authors found 12 euploid plants and 6 mixoploid plants. Of the 12 euploid plants, 6 were diploid (2n = 2x = 58) and the other 6 were tetraploid (2n =4x = 116). The chromosome numbers of the mixoploid plants varied from 59 to 203. Mttltinueleate phenomenon was also observed in the interphase cells of 10 protoplast-derived plants. Cells with binuclei or trinuelei were common and cells having heptanuclei were also seen occassionally. Muhinucleate phenomenon did not occur in the control, i. e., the donor plant, where the chromosome number was 2n = 2x = 58.     

Phenotypic and cytological variation among plants derived from anther cultures ofLilium longiflorum

Summary Anther culture of the Easter Lily (Lilium longiflorum; 2n=2x=24) was attempted in order to evaluate its potential in generating haploids for the production of hybrid cultivars. The effects of genotype, temperature (low temperature treatment of buds and high temperature treatment of cultures), sucrose concentration and growth regulators were tested. The most important factors for callus induction were the genotype and the presence of 2,4-dichlorophenoxyacetic acid. Pre-treatments at low or high temperature had no apparent effect, while high sucrose concentration was inhibitory. Callus was derived from 28 of the 108 genotypes tested and plants were regenerated. Phenotypic variations were observed among these regenerants. Somatic chromosome numbers were determined in 42 plants derived from 10 donor genotypes. Thirteen plants were diploid and 29 were mixoploid with chromosome numbers ranging from 11 to 26. Four of the mixoploid plants had a high proportion of cells with haploid chromosome numbers, particularly at early stages of development. Meiosis was examined in plants with flower buds. Most plants had 12 bivalents at Metaphase I, but also aneuploids were observed. Other irregularities included bridges and laggards at Anaphase I. The occurrence of high frequencies of haploid cells (up to 80%) in root tips suggests that some plants may be of gametic origin. Research was supported by the Easter Lily Research Foundation, the Ohio Floriculture Foundation, the Gloeckner Foundation and the Oregon Agricultural Experiment Station (technical paper no. 8398).     

Chromosome elimination and in vivo haploid production induced by Stock 6-derived inducer line in maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.)

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.     

两广茶区10个茶树品种染色体数目研究

采用植物染色体去壁、低渗、火焰干燥制片技术,分析了两广茶区１０个茶树品种染色体数目。结果表明,这１０个茶树品种均为二倍体（２ｎ＝２ｘ＝３０）;但在广东平远锅　品种中发现３个三倍体细胞;在广东连南大叶种中发现１个单倍体细胞;在清远笔架茶等６个茶树品种中均发现染色体数少于３０条的细胞。研究结果说明,茶树染色体基数具有高度的稳定性,极端气候条件的变化,很可能是导致染色体出现整倍性或非整倍性变异的原因。     

Long-term ploidy stability of shoot primordium cultures and produced plants of melon

The chromosome number of cells in the shoot primordium aggregates and produced plants of melon [Cucumis melo L. 'Prince' (2n=2x=24)] was examined. Shoot primordium aggregates were induced from shoot-tips cultured in liquid medium and shaken at low speed (2 rpm). They were maintained by subculturing small pieces (5mm<) every 4 weeks. Shoot primordium aggregates just after induction contained about 97 diploid and 3 tetraploid cells, which was similar to those maintained in shoot primordium cultures for 6 years. This indicates that the ploidy level was maintained stably. On the other hand, plants produced from the shoot primordium aggregates just after induction were either diploid, tetraploid or mixoploid with both diploid and tetraploid cells. These ploidies were again observed among plants produced from shoot primordium cultures that were 2, 3 or 4 years old. A majority of produced plants were diploid while the total frequency of tetraploids and mixoploids was less than 8 of plants produced from all ages. Therefore, the frequency of somaclonal variation with respect to ploidy among plants produced from shoot primordium aggregates is likely to be stable at a low level over the long term.     

多花水仙(Narcissus tozetta L.)染色体基数x=10和X=11之间进化关系的研究

多花水仙的染色体基数有x=10和x=11两类。基数x=10组型有两种,一种是具6长、4短的典型不对称的二形染色体组型;另一种是具有4长、2中、4短(或5长、2中、3短)的非二形染色体组型。基数x=11则具有4长、2中、5短(或5长、2中、4短)的非二型或非典型二形的染色体组型。x=10的典型不对称的二形染色体组型是原始的组型。基数x=11是从原始的x=10、2n=20组型中的(第5、6号)染色体发生不等长易位后,增加了一对短小的中着丝粒染色体而形成的。另一个x=10、2n=20的非二型新组型,可能从x=11组型丢失了短小的中着丝粒染色体衍生而来,也可能从易位后的个体所产生的不含中着丝粒染色体的雌、雄n配子结合而得到。     

美味猕猴桃原生质体再生植株细胞遗传学研究 Ⅰ．体细胞染色体数目的变化

研究了美味猕猴桃叶愈伤组织原生质体再生植株和母株（ＡｃｔｉｎｉｄｉａｄｅｌｉｃｉｏｓａｌｉｎｅＮｏ．２６）茎尖体细胞染色体数目。结果表明：母株２ｎ＝６ｘ＝１７４。所测２９株再生植株的茎尖体细胞染色体数目差异显著,多为非整倍体类型,占所测植株的７２．４％左右;体细胞染色体数目介于１４２－３１０条之间,其中２ｎ＝６ｘ＝１７４约占２０．７％,少于１７４条染色体的植株约占３１．０％,超过１７４条染色体的植株则占４８．３％左右。个别单株部分茎尖体细胞在有丝分裂后期出现染色体桥、断片和落后染色体等异常现象。并对以上现象进行了扼要的讨论。     

Cytological and breeding behavior of pentaploids derived from 3x × 4x crosses in potato

Cytology and breeding behavior of Solanum commersonii - S. tuberosum hybrids derived from 3 x x 4 x crosses was examined. The chromosome number of hybrids ranged from hypo-pentaploid (2 n=5 x - 8=52), to hyper-pentaploid (2 n=5 x + 7=67), with the euploid pentaploid 2 n=5 x=60 class predominant. The high variability in chromosome number of the 3 x x 4 x hybrids was attributed to the fact that meiotic restitution during megasporogenesis of the 3 x female may have involved poles with various chromosome numbers, resulting in 2 n eggs with 24-48 chromosomes. Microsporogenesis analyses provided evidence that chromosome pairing between S. commersonii and S. tuberosum genomes occurred. In addition, chromosome distribution at anaphase I and anaphase II revealed an average chromosome number of 29.5 and 29.1 per pole, respectively. To further study the extent of transmission of extra genome chromosomes from pentaploids, 5 x x 4 x and 4 x x 5 x crosses were performed, and the chromosome number of resulting progeny was determined. Ploidy ranged from 2 n=4 x=48 to 2 n=5 x=60 following 5 x x 4 x crosses, and from 2 n=4 x + 1=49 to 2 n=5 x=60 following 4 x x 5 x crosses. These results provided indirect evidence that the pentaploid hybrids produced viable aneuploid gametes with a chromosome number ranging from 24 to 36. They also demonstrated that gametes with large numbers of extra chromosomes can be functional, resulting in sporophytes between the 4 x and 5 x ploidy level. Fertility parameters of crosses involving various (aneuploid) pentaploid genotypes were not influenced by chromosome number, suggesting a buffering effect of polyploidy on aneuploidy. The possibility of successfully using (aneuploid) pentaploid genotypes for further breeding efforts is discussed.     

三种药用车前的染色体数目和核型的研究

<正> 车前为常用中药材,《神农本草经》和明李时珍的《本草纲目》中列为上品,以干燥全草及种子入药,有清热、明目、利尿、止泻、降低血压和镇咳祛痰等功效。 本文报道了作为“车前”中药材的三种车前属Plantago L.植物:大车前P. major L.车前P. aslatica L. 和平车前P. depressa Willd.染色体数目和核型的资料,旨在为探讨车前属内的分类和进化及为提高车前中药材的产量和质量的研究提供必要的细胞学资料。     

Alteration of chromosome behavior and synchronization of parental chromosomes after successive generations in Brassica napus x Orychophragmus violaceus hybrids.

In an earlier study, the progenies of intergeneric hybrids Brassica napus (2n = 38) x Orychophragmus violaceus (2n = 24) were investigated in successive generations (F1-F4) for the cytological phenomenon of parental genome separation during mitotic and meiotic division. In the present study, inbred lines (F5-F8) derived from 1 such hybrid were characterized for morphology, chromosome pairing behaviour, and genome composition. One F5 plant (2n = 31) with slightly yellow petals and 12:19 and 15:16 segregation ratios in its pollen mother cells (PMCs) produced F6 plants with distinct morphological characteristics and wide variations in fertility and chromosome numbers (2n = 25-38). F7 and F8 lines with distinctive morphology and wide ranges in chromsome numbers were established. In PMCs of F7 plants from 4 F6 plants, 0-12 labelled chromosomes from O. violaceus, which predominantly appeared as bivalents, were identified by genomic in situ hybridization. They behaved synchronously with B. napus chromosomes during meiotic division. The results provide molecular cytogenetic evidence of the inclusion of O. violaceus chromosomes in the original hybrids and the cytology in the hybrids documented earlier. They also show that chromosome behaviour was altered and the parental chromosomes became synchronized after successive generations.