烟草和枸杞属间原生质体电融合再生杂种植株

烟草（Ｎｉｃｏｔｉａｎａ ｔａｂａｃｕｍ Ｌ．）叶肉原生质体和枸杞（Ｌｙｃｉｕｍ ｂａｒｂａｒｕｍ Ｌ．）悬浮细胞原生质体在适宜电场条件下能以４％ —５％ 的频率发生异质融合。用过氧化物酶和超氧歧化酶同工酶方法对随机选取的１００ 个细胞系进行分析,发现杂种愈伤组织形成频率为９％ 。其中５个杂种细胞系具有分化能力,再生出大量丛生小苗。这些小苗多数在形态上兼有双亲特征并难以生根和长大。叶片酯酶同工酶分析表明,其中２ 个杂种细胞系（ＮＬ４ 和ＮＬ８）再生苗含有一条双亲没有的重组酶带。对亲本和杂种细胞系ＮＬ４ 的细胞学观察结果表明,杂种细胞系的染色体数目为２ｎ＝ ５５—８０,明显高于亲本。对亲本及ＮＬ４ 和ＮＬ８ 愈伤组织的基因组ＤＮＡ 进行ｒＤＮＡ Ｓｏｕｔｈｅｒｎ 杂交发现,ＮＬ８ 含有双亲的全部谱带,且在３．０ ｋｂ 处出现１ 条新带;ＮＬ４ 没有枸杞的特征带,但在３．０ ｋｂ 和５．５ ｋｂ 处出现２ 条新带,说明这两个杂种中的双亲ｒＤＮＡ 可能已发生分子间重组。从ＮＬ４ 愈伤组织得到４ 株形态上近似烟草的完整植株,并移栽成活     

黄花烟草和枸各间原生质体融合再生杂种小苗

利用改良的ＰＥＧ方法以２％的频率诱导黄花烟草原生质体和经ＩＯＡ失活的枸杞原生体融合。在获得的２５０块愈伤组织中,有５块为形态上与枸杞愈伤组织类似。对这５块愈伤组织的过氧化物酶和酯酶同工酶分析结果表明,其中的２块（记作Ｈｙ２和Ｈｙ５）为对称程度较高的体细胞核杂种;其它３块为不对称程度较高的体细胞核杂种。细胞学观察指出,Ｈｙ２和Ｈｙ５的平均染色体数目分别为９８．２和５９．３。此外,两个杂种的几乎所有中     

通过“供体-受体”原生质体融合将裸燕麦部分核基因组转移给普通小麦(英文)

本文进行了小麦和裸燕麦悬浮细胞原生质体的电融合,并基于双亲失活(用IOA处理受体小麦原生质体,用γ-射线照射供体裸燕麦细胞系),获得可能的杂种愈伤组织。对7块愈伤组织进行了乙醇脱氢酶(Adh)同工酶筛选,发现5块表现出双亲特征酶带。对3个杂种细胞系进行5种同工酶分析,证实它们均为稳定的不对称体细胞核杂种细胞系;它们表现出小麦的完整谱带和裸燕麦的部分谱带。对2个杂种细胞系及亲本的核糖体DNA Southern分析结果表明只有一个杂种细胞系(HB 95)含有双亲的全部谱带。细胞学观察表明,2个杂种细胞系的染色体数目均显著高于双亲。从杂种细胞系HB 94中分化出叶原基等分化结构。Adh同工酶分析表明,这些分化结构具有和母体细胞系完全相同的杂种谱带。     

单倍体小麦与羊草的属间体细胞杂交

以失去植株再生能力的小麦单倍体愈伤组织和羊草二倍体愈伤组织为材料,游离原生质体,并用紫外线自理２羊草原生质体,用ＰＥＧ法融合,对融合克隆进行染色体和同工酶分析,在已贩２６个克隆中有２１个是杂种,其中有一个克隆再生出短命小植株,结果 体小麦与二倍体草的不对称融合虽然再生互补效应不如二倍体小麦,然而杂种优先生长的现象仍然比较明显。如果改善实验条件和双亲原始的再生能力,这种融合方式仍然可以利用。     

通过“供体—受体”原生质体融合将裸燕麦部分核基因组转移给普通小麦

本文进行了小麦和裸燕麦悬浮细胞原生质体的电融合,并基于双亲失活（用ＩＯＡ处理受全小麦原生质体,用γ－射线照射供体裸燕细胞系）,获得可能的杂种愈伤组织。对７块愈伤组织进行了乙醇脱氢酶（Ａｄｈ）同工酶筛选,发现５块表现出双亲特征酶带。对３个杂种细胞系进行５种同工酶分析,证实它们均为稳定的不对称体细胞核杂种细胞系;它们表现出小麦的完整谱带和裸燕麦的部分谱带。对２个杂种细胞系及亲本的核糖体ＤＮＡ Ｓｏｕｔ     

原生质体融合获得柑桔种间体细胞杂种

粗柠檬(Citrus jambhiri Lush)叶肉原生质体与哈姆林甜橙(C.sinensis L.Osbeck)胚性悬浮细胞系原生质体经PEG诱导融合,培养7天时原生质体恢复分裂。再生的胚状体在含有GA_3的培养基中萌发出茎芽。茎芽经生根诱导成为完整植株。对首批再生的5棵植株进行染色体检查,结果表明,全为四倍体,2n=4x=36。淀粉胶电泳分析过氧化物酶同工酶,结果显示这5棵植株为体细咆杂种。粗柠檬和哈姆林甜橙在该位点上均为同质结合,基因型分别是MM和FF。体细胞杂种含有双亲的酶带,基因型为MMFF。杂种植株生长旺盛,根系发达,叶片及植株形态介于双亲之间。本文对其作为砧木品种的可能性等问题作了讨论。     

普通小麦与无芒雀麦不对称体细胞杂交的研究

普通小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）９９Ｐ原生质体与经紫外线照射的无芒雀麦（ＢｒｏｍｕｓｉｎｅｒｍｉｓＬｅｙｓ）愈伤组织来源的原生质体用ＰＥＧ法诱导融合。融合再生的３个单细胞克隆（Ｎｏ．１～Ｎｏ．３）经染色体、同工酶和ＲＡＰＤ分析表明,它们均为杂种细胞系。Ｎｏ．１克隆形成的愈伤组织分化出大量白化苗,其叶片同工酶和ＲＡＰＤ分析均出现双亲特征谱带及新带,白化苗的染色体数目为４２～５４,大于亲本小麦,并具有无芒雀麦的小染色体和染色体断片,确认它们为不对称体细胞杂种。     

普通小麦与玉米不对称体细胞杂交的研究

以长期继代培养,经分化实验证明无分化能力的普通小麦（Triticum aestivum L.)济南177原生质体为受体,以经380uW/cm^2紫外线处理的继代第3－5天的墨西哥黑甜玉米（Zea mays L.cv.Sccharina F.Nigera)胚性悬浮组织原生质体为供体,使用PEG的方法诱导融合。融合再生的18个单细胞克隆的愈伤组织经形态学比较、染色体检查、同工酶分析、5S rRNA间隔序列分析,确认克隆1为杂种愈伤组织,杂种愈伤组织再生出来的白化苗未进行杂种鉴定。同时,初步探讨了紫外线对玉米原生质体的影响。     

烟草种间的体细胞杂交──Ⅰ．通过原生质体融合将波缘烟草部分核基因组转移给普通烟草

通过“供体──受体”原生质体融合获得５个“波缘烟草＋普通烟草”体细胞杂种细胞系（ＴＵ＿１至ＴＵ＿５）。对５个杂种细胞系的细胞学观察表明,其中２个系为多细胞融合产物,其平均染色体数目分别为１６７．２和１９８．４;３个系为二细胞融合产物,其平均染色体数目分别为５４．３７０．６和６２．８。杂种细胞系的一个明显特征是所有观察的中期细胞均存在数量不等的畸变染色体。对５个杂种细胞系再生植株叶片苹果酸脱氢酶和酯酶的同工酶分析结果表明,它们均为程度不同的不对称核杂种,即只含有供体亲本（波缘烟草）的部分核基因组。以小麦ｒＤＮＡ为探针对杂种细胞系基因组ＤＮＡ的Ｓｏｕｔｈｅｒｎ杂交结果表明,杂种中双亲的载有ｒＤＮＡ的染色体可能均有部分消除;此外,杂种中新ＤＮＡ片段的存在说明双亲ｒＤＮＡ可能发生了分子间重组。两个由多细胞融合产生的杂种细胞系（ＴＵ＿２和ＴＵ＿５）再生苗不易生根而且形态上异常。３个由二细胞融合产生的杂种细胞系（ＴＵ＿１、ＴＵ＿３和ＴＵ＿４）再生苗可生根长大,形态上类似受体亲本;对其根尖的细胞学观察表明,染色体数目在５１─６６之间,说明均为只含有少量供体亲本染色体的不对称核杂种。     

普通小麦与簇毛麦原生质体的紫外线融合

从来源于普通小麦品种济南177（Triticum aestivum cv.Jinan 177）悬浮细胞系的原生质体与来源于簇毛麦（Haynaldia villosa）胚性愈伤组织的原生质体融合获得体细胞杂种。供体簇毛麦原生质体在融合之前用紫外线照射30s或1min,紫外线剂量为360Цw/cm^2。仅由紫外线照射30s的组合获得再生愈伤组织克隆。细胞学、生物化学及PCR分析结果证实了再生克隆的杂种性质。用线粒体基因特异的探针进行的RFLP分析的结果表明,杂种中含有融合双亲的线粒体并且发生了重组。由杂种愈伤组织再生得到白化苗。讨论了紫外线对融合产物的影响。     

Intergeneric Somatic Hybrid Plants of Nicotiana tabacum L. and Lycium barbarum L. by Protoplast Electrofusion

Mesophyll protoplasts of Nicotiana tabacum L. and protoplasts from cell suspension of Lycium barbarum L. were heterofused by electrofusion with a frequency of ca. 4%--5%. One hundred cell lines were selected at random identified by isozyme analysis with peroxidase and superoxide dismatase, and the differences from their parent were found. Results indicated that 9 cell lines expressed enzymatic bands characteristic of both parents. Five of the 9 cell lines were highly morphogenic and regenerated numerous young shoots that manifested morphological traits specific to both parents. However, these shoots never grew up or regenerate roots. Esterase analysis of leaf material from the regenerants of 5 morphogenic hybrid cell lines demonstrated that two of them (NL4 and NL8) expressed an unique hybrid band which were not shown in either parents. Cytological observation on parental and NL4 hybrid cell lines revealed that the somatic chromosome number of NL4 varied from 58 to 80, significantly higher than that of either parents. Ribosomal DNA analysis of NL4 and NL8 showed that NL8 covered all fragments of both parents: NL4 did not have the fragments characteristic of Lyciurn barbarurn L. Both hybrids had new fragments, suggestive of intermolecular recombination of rDNAs of the parents. Four normal plants morphologically similar to tabacco parent were obtained from hybrid cell hne NL4, which survived after being transferred to soil. Cytological analysis of root-tips from one of the plants indicated that it has ca. 58 chromosomes. This paper also discussed the problems on the production frequency and incompatibility of somatic cell hybrid.     

Morphological and molecular characterization of fertile tetraploid somatic hybrids produced by protoplast electrofusion and PEG-induced fusion between Lycopersicon esculentum Mill. and Lycopersicon peruvianum Mill.

Summary Mesophyl protoplasts of two genotypes of cultivated tomato (Lycopersicon esculentum Mill.) and one of its wild relative species (Lycopersicon peruvianum Mill.) were fused by using electrofusion and polyethyleneglycol-induced fusion. Forty-three fertile tetraploid somatic hybrid plants, each deriving from separate calli, were recovered from both fusion procedures. Electrofusion appeared more efficient than chemical fusion for the production of somatic hybrids. These plants appeared morphologically similar, whatever the fusion procedure and tomato genotype. They had intermediate leaf, inflorescence, and flower morphology. After self-pollination, the hybrids set fruit of intermediate size and color. The hybrid nature of these plants was confirmed by isoelectric focusing of the Rubisco small subunits used as nuclear markers. L. esculentum and L. peruvianum were distinguished by means of two chloroplast markers: CF1-ATPase subunit as analyzed by isoelectro-focusing and ct DNA restriction patterns. All hybrids displayed both ct markers of only one parent with no biased transmission. Mitochondrial (mt) DNAs were prepared from flower buds by using miniaturized CsCl gradients. Preliminary analysis indicated that mt genomes from the hybrids all differed from those of both parents. mt DNA Sall restriction enzyme analysis revealed that all but two hybrids contained one novel fragment of 13.5 kb. Gene mapping experiments showed that the mt apocytochrome b and ATPase subunit 9 homologies in the somatic hybrid mt DNA resembled L. esculentum and L. peruvianum, respectively; the mt nad5 probe distinguished at least four distinct patterns in the hybrids. These results indicated that mt DNA rearrangements involving intergenomic recombinations occurred through protoplast fusion. A greater mt DNA polymorphism was induced with chemical fusion than with electrofusion.     

Genotyping of somatic hybrids between <Emphasis Type="Italic">Festuca arundinacea</Emphasis> Schreb. and <Emphasis Type="Italic">Triticum aestivum</Emphasis> L.

In order to genotype hybrid genomes of distant asymmetric somatic hybrids, we synthesized hybrid calli and plants via PEG-mediated protoplast fusion between recipient tall fescue (Festuca. arundinacea Schreb.) and donor wheat (Triticum aestivum L.). Seventeen and 25 putative hybrid clones were produced from the fusion combinations I and II, each with the donor wheat protoplast treated by UV light for 30 s and 1 min, respectively. Isozyme and RAPD profiles confirmed that ten hybrid clones were obtained from combination I and 19 from combination II. Out of the 29 hybrids, 12 regenerated hybrid plants with tall fescue phenotype. Composition and methylation-variation of the nuclear and cytoplasmic genomes of some hybrids, either with or without regenerative ability, were compared by genomic in situ hybridization, restriction fragment length polymorphism, and DNA methylation-sensitive amplification polymorphism. Our results indicated that these selected hybrids all contained introgressed nuclear and cytoplasmic DNA as well as obvious methylation variations compared to both parents. However, there were no differences either in nuclear/cytoplasmic DNA or methylation degree between the regenerable and non-regenerable hybrid clones. We conclude that both regeneration complementation and genetic material balance are crucial for hybrid plant regeneration.     

Somatic hybrid plants between the forage legumes Medicago sativa L. and Medicago arborea L.

Interspecific somatic hybrid plants were obtained by symmetrical electrofusion of mesophyll protoplasts of Medicago sativa with callus protoplasts of Medicago arborea. Somatic hybrid calli were picked manually from semi-solid culture medium after they were identified by their dual color in fluorescent light. Twelve putative hybrid calli were selected and one of them regenerated plants. The morphogenesis of the somatic hybrid calli was induced by the synthetic growth regulator 1,2 benzisoxazole-3-acetic acid. Somatic hybrid plants showed intensive genome rearrangements, as evidenced by isozyme and RFLP analysis. The morphology of somatic hybrid plants was in general intermediate between the parents. The production of hybrids by protoplast fusion between sexually incompatible Medicago species is related to the in vitro respon siveness of the parental protoplasts. The possibility of using somatic hybrid plants in alfalfa breeding is discussed.     

Rapid alterations of DNA sequence and cytosine methylation induced by somatic hybridization between Brassica oleracea L. var. italica and Brassica nigra (L.) Koch

Somatic hybrids were produced between hypocotyl protoplasts of Brassica oleracea L. var. italica (broccoli) and mesophyll protoplasts of B. nigra (black mustard) using polyethylene glycol—mediated protoplast fusion. A total of fifteen somatic hybrids derived from six calli (no. 1, 3, 8, 21, 38 and 44) were obtained. Cytological analysis showed that all the hybrids possessed 2n = 34, the sum of the parental chromosomes and the genomic in situ hybridization analysis revealed their BBCC genome constitutes. Moreover, all the hybrids exhibited different type of meiosis abnormalities, which were more usually observed in pollen mother cells at metaphase II/anaphase II (MII/AII, 16.1–39.6 %) than at metaphase I/anaphase I (MI/AI, 7.8–15.2 %). Simple sequence repeat analysis revealed that all the hybrids showed the same cytoplasmic genome as broccoli. Structure and methylation-variation of the nuclear were investigated by amplified fragment length polymorphism (AFLP) and DNA methylation-sensitive amplification polymorphism (MSAP). Our results indicated that all the hybrids mainly had the AFLP and MSAP banding patterns from the addition of two parents plus some alterations. The incidences of the AFLP polymorphic bands in the hybrids showed a range of 9.8–18.7 % while the DNA methylation alteration in the hybrid no. 38 was 4.07 %. This result suggested that somatic hybridization could induce more DNA sequence changes than methylation alterations in the early stage of allotetraploid hybrids.     

Interspecific hybridization between the cultivated potato Solanum tuberosum subspecies tuberosum L. and the wild species S. circaeifolium subsp. circaeifolium Bitter exhibiting resistance to Phytophthora infestans (Mont.) de Bary and Globodera pallida (Stone) Behrens

Summary Somatic fusions between the cultivated potato Solanum tuberosum and the wild species S. circaeifolium subsp. circaeifolium Bitter were produced in order to incorporate desirable traits into the potato gene pool. Selection of the putative hybrids was based on a difference in callus morphology between the hybrids and their parents, with the hybrids showing typical purple-colored cells in otherwise green calli. In all, 17 individual calli regenerated to plants. Of the nine plants that could be transferred to the greenhouse, eight showed a hybrid and one a parental morphology. Restriction fragment length polymorphism (RFLP) analysis confirmed the hybrid character in the former group. Chloroplast counts in stomatal guard cells and flow cytometric determination of nuclear DNA content showed that four hybrid plants were tetraploid (4x), one was mixoploid (5x–8x), and the others were polyploid (6x; 8x). Three out of four tetraploid hybrids were found to be fully resistant to Phytophthora infestans, and all four hybrids were resistant to Globodera pallida pathotypes Pa2 and Pa3. It was further observed that the type and amount of steroidal glycoalkaloids varied among the tubers of the parents and the hybrids. Using the hybrids as female parents in crosses with S. tuberosum, viable seeds could be obtained. This demonstrates the potential of these hybrids in practical plant breeding.     

Asymmetric somatic hybridization between wheat (Triticum aestivum) and Avena sativa L.

Common wheat is one of the most important cereal crops in the world. The improvement of its yield and quality by the introduction of heterologous gene(s) is very significant. Avena sativa L. (2n = 42), belonging to the Avena tribe, possesses resistance to drought, coldness and many dis-eases. Its contents of proteins and fat in seed, especially lysine and unsaturated fatty acid are highest in crops, therefore it is regarded as healthy food. Sexual hybridization between wheat and Avena sativa…     

鹰嘴紫云英甲硫氨酸抗性系原生质体培养及植株再生

本研究建立了鹰嘴紫云英(AstragaluscicerL.)甲硫氨酸抗性系原生质体再生植株的实验体系。以茎切段诱导的松软愈伤组织为材料,通过酶法游离出大量有活力的原生质体。原生质体经培养持续细胞分裂形成了愈伤组织,并分化出再生苗。比较了不同培养基、培养密度对原生质体形成细胞分裂和再生的影响。结果表明,原生质体以2×105个/ml的植板密度,在附加2.0mg/L2,4-二氯苯氧乙酸(2,4-D)、0.2mg/L6-苄氨基嘌呤(6-BA)、200mg/L水解酪蛋白、2%蔗糖和0.3mol/L甘露醇DPD培养基中培养后,其分裂频率达38.3%。原生质体培养形成的愈伤组织仍具有对甲硫氨酸的抗性。转移到附加10mg/LKT、0.5mg/LNAA的MS分化培养基上,获得大量的再生苗。     

Production and characterization of somatic hybrid plants between leek (Allium ampeloprasum L.) and onion (Allium cepa L.)

 Results are reported on the production and characterization of somatic hybrids between Allium ampeloprasum and A. cepa. Both symmetric and asymmetric protoplast fusions were carried out using a polyethylene-based mass fusion protocol. Asymmetric fusions were performed using gamma ray-treated donor protoplasts of A. cepa and iodoacetamide-treated A. ampeloprasum protoplasts. However, the use of gamma irradiation to eliminate or inactivate the donor DNA of A. cepa proved to be detrimental to the development of fusion calli, and thus it was not possible to obtain hybrids from asymmetric fusions. The symmetric fusions yielded a high number of hybrid calli and regenerated plants. The analysis of the nuclear DNA composition using interspecific variation of rDNA revealed that most of the regenerated plants were hybrids. Flow cytometric analysis of nuclear DNA showed that these hybrid plants contained a lower DNA content than the sum of the DNA amounts of the parental species, suggesting that they were aneuploid. A shortage of chromosomes in the hybrids was confirmed by genomic in situ hybridization. Chromosome counts in metaphase cells of six hybrids revealed that these plants lacked 2–7 leek chromosomes. One hybrid showed also the loss of onion chromosomes. The hybrids had an intermediate phenotype in leaf morphology. The application of these somatic hybrids in breeding is discussed. Received: 7 April 1997 / Accepted: 10 September 1997