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1.
Otto Schieder 《Molecular & general genetics : MGG》1978,162(2):113-119
Summary Following fusion of protoplasts from a chlorophyll-deficient diploid mutant of Datura innoxia Mill. which can be regenerated to shoots, with green wild-type protoplasts of Datura stramonium L. var. tatula L. which can not, it was possible to isolate 49 green hybrid calli on agar medium. Most of these somatic hybrid calli gave rise to leaves and shoots. The chromosome numbers of the somatic hybrids were determined: 15 were tetraploid (amphidiploid), 24 hexaploid, and the other showed an aneuploid chromosome number.In a similar experiment protoplasts of the Datura innoxia mutant were fused with green wild-type protoplasts of Datura discolor Bernh. which are also not able to be regenerated, four green calli were obtained from which leaves and shoots developed after some transfers on agar medium. Three of them showed the amphidiploid (48) chromosome number, whereas one possessed an aneuploid number of 46 chromosomes.After transfer of rooted shoots to soil flowering plants could be obtained in both combinations. The habits of the somatic hybrids in both combinations were intermediate between the habits of the respective parental plants.Dedicated to my father, Prof. Dr. Theodor Schieder, on the occasion of his 70th birthday. 相似文献
2.
Otto Schieder 《Molecular & general genetics : MGG》1976,149(3):251-254
Summary Ten different mutants with altered pigment patterns were isolated following X-irradiation of approximately 105 haploid protoplasts of Datura innoxia Mill. Seven of the selected strains gave rise to shoots and 3 to leaves only. The mutants were selected from light green or white calli, which had developed 4 weeks after transfer of developing cell clusters onto B5 agar medium containing 0.5 mg/l BAP (Gamborg et al., 1968). Of the 10 mutant strains 5 were light green, two were yellow, one was pale yellow and one was white. One additional strain does not possess anthocyanin in its stems; a feature chracteristic of the wildtype is the possession of anthocyanin. This strain is able to grow in soil and has now flowered. None of the mutants obtained is haploid. Nine are diploid and the other is tetraploid. The chlorophyll deficient strains can be propagated on B5 agar medium supplemented with higher concentration of sucrose than normally required for the growth of the wild-type. 相似文献
3.
M. C. Daunay M. H. Chaput D. Sihachakr M. Allot F. Vedel G. Ducreux 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,85(6-7):841-850
Summary In order to produce fertile somatic hybrids, mesophyll protoplasts from eggplant were electrofused with those from one of its close related species, Solanum aethiopicum L. Aculeatum group. On the basis of differences in the cultural behavior of the parental and hybrid protoplasts, 35 somatic hybrid plants were recovered from 85 selected calli. When taken to maturity either in the greenhouse or in the field, the hybrid plants were vigorous, all rapidly overtopping parental individuals. The putative hybrids were intermediate with respect to morphological traits, and all of their organs were larger, particularly the leaves and stems. DNA analysis of the hybrids using flow cytometry in combination with cytological analysis showed that 32 were tetraploids, 1 hexaploid and 2 mixoploids. The hybrid nature of the 35 selected plants was confirmed by a comparison of the isoenzyme patterns of isocitrate dehydrogenase (Idh), 6-phosphogluconate dehydrogenase (6-Pgd) and phosphoglucomutase (Pgm). Chloroplast DNA (ctDNA) restriction analysis using Bam HI revealed that among the 27 hybrid plants analyzed, 10 had S. aethiopicum patterns and the 17 remaining hybrids exhibited bands identical with those of eggplant without any changes. All of the somatic hybrid plants flowered. Both parental plants had 94% stainable pollen, while the hybrids varied widely in pollen viability ranging from 30% to 85%. The somatic hybrids showed high significant variation in fruit production. Nevertheless, there was a tendency for low fertility to be associated often with S. aethiopicum chloroplast type and/or with an abnormal ploidy level, while good fertility was mostly associated with the tetraploid level and eggplant chloroplasts. Interestingly, 2 tetraploid somatic hybrid clones were among the most productive, yielding up to 9 kg/plant. As far as the fertility of the F1 sexual counterpart was concerned, only 2 fruits of 50 g were obtained. Hybrid fertility in relation to phylogenetic affinities of the fusion partners is discussed. 相似文献
4.
One of the methods which enhances production of plant secondary metabolites including alkaloids is the use of abiotic elicitors
in vitro. The aim of the study was the employment of aluminum (Al) as an abiotic elicitor in such concentrations, which were
not stressful for the plant, to avoid intense growth limiting, but could elicit tropane alkaloid biosynthesis. The in vitro
propagated plantlets of Datura innoxia were exposed to different concentrations of AlCl3 (0, 25, 75 and 225 μM) to determine its effects on hyoscyamine and scopolamine contents in roots and shoots, which were analyzed
by HPLC. Antioxidant enzyme activities were determined by spectrophotometer. Results showed that aluminum reduced shoots’
and roots’ fresh weights and the reduction in roots were more than the shoots. In addition, Al had significant positive effects
on hyoscyamine and scopolamine contents especially in roots of the plantlets and AlCl3 caused ROS production in shoots. These findings suggest that aluminum can likely elicit the tropane alkaloid biosynthesis
in D. innoxia plantlets in vitro. 相似文献
5.
Yakov I. Ratushnyak Nickolai N. Cherep Anna V. Zavgorodnyaya Sergei A. Latypov Irina V. Borozenko Raiysa I. Rachkovskaya Yuri Y. Gleba 《Molecular & general genetics : MGG》1993,236(2-3):427-432
Summary Thirteen nuclear asymmetric hybrids were regenerated under selective conditions following fusion of chlorophyll-deficient protoplasts from cultivated tomato (Lycopersicon esculentum Mill.) and -(-irradiated protoplasts from the wild species Lycopersicon peruvianum var. dentatum Dun. All hybrid plants were classified as being asymmetric based on morphological traits, chromosome numbers and isozyme patterns. The majority of the hybrids inherited Lycopersicon peruvianum var. dentatum chloroplasts. Mitochondrial DNA analysis revealed mixed mitochondria populations deriving from both parents in some of the hybrids and rearranged mitochondrial DNA in others. The asymmetric hybrids express some morphological traits that are not found in either of the parental species. Fertile F1 plants were obtained after self-pollination of the asymmetric hybrids in four cases. The results obtained confirm the potential of asymmetric hybridization as a new source of genetic variation, and as a method for transferring of a part of genetic material from donor to recipient, and demonstrate that it is possible to produce fertile somatic hybrids by this technique. 相似文献
6.
After fusion of protoplasts from a diploid (2n=24) and a tetraploid (4n=48) chlorophyll-deficient mutant of Datura innoxia Mill. with diploid (2n=72) green wild-type protoplasts of Atropa belladonna L. thirteen somatic hybrids could be selected, most of which had already started to produce leaves and shoots. Hybrid calli were recognizable by the production of hairs, typical for Datura innoxia, and the green colour, derived from Atropa belladonna. Further proof for the hybrid nature was furnished by cytological investigations. The metaphase chromosomes of both species are easily distinguishable in their size: chromosomes of Datura innoxia are about twice as large as those of Atropa belladonna. The chromosome numbers of the hybrids varied from ca. 84 to ca. 175.Abbreviations BAP
6-benzylaminopurine
- NAA
-naphthalene acetic acid 相似文献
7.
N. V. Borisjuk V. P. Momot Y. Gleba 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,76(1):108-112
Summary Behavior of ribosomal RNA genes in the process of somatic hybridization was analyzed using hybrids Nicotiana tabacum + Atropa belladonna. Blothybridization of parental species DNAs to 32P-rDNA specific probes revealed two classes of ribosomal repeats in both tobacco and nightshade; their length was 11.2 kb, 10.4 kb (tobacco) and 9.4 kb, 10.2 kb (night-shade). For analysis of hybrids, labelled 32P rDNA specific probes were hybridized to DNA of parental species and somatic hybrids digested with restriction endonucleases EcoR1, EcoRV and BamH1. A new class of ribosomal DNA repeat, absent in parental species, was found in hybrid line NtAb-1. Possible mechanisms of appearence of a new rDNA class in the process of somatic cell fusion are discussed. 相似文献
8.
F. Begum S. Paul N. Bag S. R. Sikdar S. K. Sen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(6-7):1167-1172
An attempt to transfer genes from droughttolerant Diplotaxis harra, a wild relative of Brassica species, to an elite oil-yielding cultivar, B-85, of mustard (Brassica juncea) was made through protoplast fusion, as the two plant systems are sexually incompatible. By following the standard protocol for PEG-mediated protoplast fusion followed by high pH, high Ca++, DMSO treatment and appropriate cell-culture technique, 16 presumptive somatic hybrid plants could be regenerated. Chromosomal analysis of four such somatic hybrids revealed that three of them were asymmetric. Analysis of morphological characters, meiotic chromosomes, and esterase isoenzyme pattern revealed that all the somatic hybrids were different from each other. Furthermore four chromosomes of each genome could undergo homoeologous pairing at meiosis indicating the possibilities for genetic recombination and chromosomal rearrangements. Irregular distribution of chromosomes at anaphase-II at meiosis has been a consistent feature of these plants. Eventually, pollen of all the somatic hybrids showed complete infertility preventing the recovery of any selfed seed. Nevertheless, ovule fertility of one somatic hybrid was not totally impaired as it had set some seeds upon backcrossing with the B. juncea parent. The esterase isoenzyme banding pattern of 24 individual progeny plants of this backcross provided evidence for their recombinant nature. It was thus confirmed that a transfer of genetic traits from Diplotaxis harra to B. juncea had indeed taken place. Furthermore, it was conceptualised that a transfer of alien genes through the protoplast-fusion technique is primarily possible in situations where meiotic pairing of the chromosomes of the two participating genomes generates recombinant gametocytes which can pass through subsequent filial generations. 相似文献
9.
B. Nzau Matondo M. Ovidio J. C. Philippart P. Poncin 《Zeitschrift fur angewandte Ichthyologie》2011,27(3):859-867
The aim of this study was to further test the viability of the roach Rutilus rutilus × common bream Abramis brama hybrid in terms of reproductive behaviour and sexual production. Egg release, mating and aggressive acts in reproductive behaviour, as well as absolute fecundity and sperm density in milt for sexual production were examined in the first generation of these hybrids at their first sexual maturity. The F2 and backcrosses of hybrids were also studied. The results revealed that these hybrids expressed a normal and typical mating behaviour, producing viable gametes. Under experimental reproduction between hybrids (hybrid reproduction), the number of egg‐release acts (range, 21–66) was nearer (χ2 test, P > 0.05) the number of mating acts (11–65). Moreover, hybrid males exhibited territorial and aggressive behaviours. However, in experimental reproduction of female and male hybrids mixed with parental males (mixed reproduction), the egg‐release act and the mating act were inhibited by the intense territorial and aggressive activities of the common bream male. Absolute fecundity values (median, <2.2 × 103 eggs) and sperm density (<7 × 109 spermatozoa ml?1) of hybrids showed a greater decrease (U test, P < 0.05) than in parental species (median, >6.0 × 103 eggs and >14 × 109 spermatozoa ml?1, respectively). Nevertheless, these hybrids were fertile. F2 and backcross generations were produced, although with a significantly lower viable hatching rate (FEP test, P < 0.05) in F2 individuals from the female and its corresponding hybrid male (<6%), indicating a very low chance of survival in rivers. 相似文献
10.
B. Nzau Matondo A. B. Nlemvo M. Ovidio P. Poncin J. C. Philippart 《Zeitschrift fur angewandte Ichthyologie》2008,24(1):63-67
Fertility in first‐generation hybrids of roach, Rutilus rutilus, and silver bream, Blicca bjoerkna, was investigated. Sperm and egg production of hybrids at first sexual maturity were examined. Eggs from female hybrids were artificially fertilized with the sperm of a corresponding hybrid male; a hybrid male from the reciprocal crossbreeding; a parental species male R. rutilus; and a parental species male B. bjoerkna. The results revealed that gametogenesis was normal in female hybrids. However, in male hybrids, a low efficiency of gametogenesis was observed. The semen of male hybrids was extremely dilute, with spermatozoa concentration lower than that in parental species. Nevertheless, these F1 hybrids (males and females) from reciprocal crossbreeding were fertile. F2 and backcross generations were produced, but F2 crosses from the female hybrid and corresponding hybrid male displayed a drastically slower hatching rate. Also higher proportions of deformed embryos were hatched than in other post‐F1‐generation crosses. 相似文献
11.
Stephen V. Evola 《Molecular & general genetics : MGG》1983,189(3):455-457
Summary In somatic hybrids of each of four chlorate-resistant cell lines of Nicotiana tabacum L., two of which were also nitrate-nonutilizing, and a common chlorate-sensitive parent, nitrate utilization and/or chlorate resistance were found to be recessive traits. Complementation for nitrate utilization was observed in somatic hybrids of the two nitrate-nonutilizing cell lines. No chlorate-resistant or nitrate-nonutilizing seedlings were detected among a large number of progeny resulting from the self-fertilization of a somatic hybrid plant one of whose parents was one of the nitrate-nonutilizing cell lines. 相似文献
12.
M. Skarzhinskaya M. Landgren K. Glimelius 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(8):1242-1250
Intertribal Brassica napus (+) Lesquerella fendleri hybrids have been produced by polyethylene glycol-induced fusions of B. napus hypocotyl and L. fendleri mesophyll protoplasts. Two series of experiments were performed. In the first, symmetric fusion experiments, protoplasts from the two materials were fused without any pretreatments. In the second, asymmetric fusion experiments, X-ray irradiation at doses of 180 and 200 Gy were used to limit the transfer of the L. fendleri genome to the hybrids. X-ray irradiation of L. fendleri mesophyll protoplasts did not suppress the proliferation rate and callus formation of the fusion products but did significantly decrease growth and differentiation of non-fused L. fendleri protoplasts. In total, 128 regenerated plants were identified as intertribal somatic hybrids on the basis of morphological criteria. Nuclear DNA analysis performed on 80 plants, using species specific sequences, demonstrated that 33 plants from the symmetric fusions and 43 plants from the asymmetric fusions were hybrids. Chloroplast and mitochondrial DNA analysis revealed a biased segregation that favoured B. napus organelles in the hybrids from the symmetric fusion experiments. The bias was even stronger in the hybrids from the asymmetric fusion experiments where no hybrids with L. fendleri organelles were found. X-ray irradiation of L. fendleri protoplasts increased the possibility of obtaining mature somatic hybrid plants with improved fertility. Five plants from the symmetric and 24 plants from the asymmetric fusion experiments were established in the greenhouse. From the symmetric fusions 2 plants could be fertilised and set seeds after cross-pollination with B. napus. From the asymmetric fusions 9 plants could be selfed as well as fertilised when backcrossed with B. napus. Chromosome analysis was performed on all of the plants but 1 that were transferred to the greenhouse. Three plants from the symmetric fusions contained 50 chromosomes, which corresponded to the sum of the parental genomes. From the asymmetric fusions, 11 hybrids contained 38 chromosomes. Among the other asymmetric hybrids, plants with 50 chromosomes and with chromosome numbers higher than the sum of the parental chromosomes were found. When different root squashes of the same plant were analysed, a total of 6 plants were found that had different chromosome numbers. 相似文献
13.
Anne-marie A. Wolters Annette C. Vergunst Frank van der Werff Maarten Koornneef 《Molecular & general genetics : MGG》1993,241(5-6):707-718
Protoplast fusion experiments between Lycopersicon esculentum or L. peruvianum and Nicotiana tabacum or N. plumbaginifolia were performed to investigate the possibility of producing symmetric and asymmetric somatic hybrids between these genera. These fusions, which involved 1.7 × 108 protoplasts, yielded 35 viable hybrid calli. Plant regeneration was successful with two calli. One of these regenerants flowered, but developed no fruits. Analysis of the nuclear DNA by means of dot blot hybridization with species-specific repetitive DNA probes combined with flow cytometry, revealed that the nuclei of most hybrid calli contained the same absolute amount of Nicotiana DNA as the Nicotiana parent or (much) less, whereas the amount of Lycopersicon DNA per nucleus was 2–5 times that of the parental genotype. Eighteen of the 34 hybrids analyzed possessed Lycopersicon chloroplast DNA (cpDNA), whereas the other 16 had DNA from Nicotiana chloroplasts. The cpDNA type was correlated with the nuclear DNA composition; hybrids with more than 2C Nicotiana nuclear DNA possessed Nicotiana chloroplasts, whereas hybrids with 2C or less Nicotiana nuclear DNA contained Lycopersicon chloroplasts. Mitochondrial DNA (mtDNA) composition was correlated with both nuclear DNA constitution and chloroplast type. Hybrids possessed only or mainly species-specific mtDNA fragments from the parent predominating in the nucleus and often providing the chloroplasts. The data are discussed in relation to somatic incompatibility which could explain the low frequency at which hybrids between Lycopersicon and Nicotiana species are obtained and the limited morphogenetic potential of such hybrids. 相似文献
14.
应用SRAP分子标记方法对冬枣×宁梨巨枣的子代进行了分子鉴定及遗传多样性分析。采用构建基因池的方法对SRAP分子标记引物进行筛选,从88对引物中筛选出15对多态性好、主带清晰的引物,并对子代进行了真实性鉴定及多态性分析。结果表明:(1)15对引物共产生95个多态性条带,平均每对引物产生6.3个多态性条带,显示了较高的多态性比率。(2)80个子代中44个具有父本特征带,鉴定为真杂种。子代遗传多样性及UPGMA聚类分析表明,子代个体与亲本间的遗传相似系数在0.55~0.98之间,个体差异明显。该研究结果为枣树杂交育种提供了重要的分子证据。 相似文献
15.
K. C. Sink J. B. Power N. J. Natarella 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1978,53(5):205-208
Summary Attempts at the reciprocal cross between Petunia parodii and P. inflata using standard emasculation and pollination techniques failed. Limited pollen tube growth down the style in reciprocal crosses led to reproductive isolation between the self-compatible P. parodii and self-incompatible P. inflata. The interspecific hybrid was successfully produced by bud-pollination of P. parodii with P. inflata as the male parent in 22 percent of attempts, but not in the opposite direction. In vitro pollination of P. parodii ovaries with P. inflata pollen also produced hybrids. The small size of the ovary made it technically impossible to use P. inflata as the female parent for in vitro pollination. The interspecific hybrids were intermediate, as compared to the two parents, for six of the seven plant and flower characters measured. Furthermore, the hybrids had high pollen fertility, set abundant seed upon self-pollination, and readily inter-crossed with the parental species. The results are consistent with a high degree of chromosomal homology in the parental species and with minor genetic divergency leading to reproductive isolation that is pre-zygotic in nature. Overcoming the barriers to cross-incompatibility by practical techniques resulted in fertile interspecific hybrids that segregated for parental characters. The potential value of employing the parental species in somatic hybridization experiments is discussed.Michigan Agricultural Experiment Station Journal Article No. 8404 相似文献
16.
J. O. Rasmussen J. P. Nepper O. S. Rasmussen 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(3-4):403-410
Fourteen somatic hybrids generated by electrofusion of mesophyll protoplasts from a non-flowering dihaploid S. tuberosum clone, DHAK-11, and a male-sterile dihaploid clone S. tuberosum, DHAK-33, were grown in the greenhouse and subjected to morphological assessments and tests for fertility and resistance to the white potato cyst nematode Globodera pallida pathotypes Pa2 and Pa3. The ploidy level of the hybrids ranged from 38 to 63 chromosomes. All hybrids developed flowers with violet petals except for one, hy-56, that possessed red petals. The colour of the tuber skin was purple in all hybrids except in hy-56 where the tuber skin was red. All of the hybrids were female fertile and generated viable seeds. Near-tetraploid hybrids produced the highest number of seeds per fruit and these seeds had a normal size. Hybrids with 58 or more chromosomes produced smaller seeds and less seeds per fruit. The germination frequency of the seeds was not influenced by the chromosome number of the hybrids. Pollen viability was determined and the male fertility of three hybrids was tested. Pollination with these three hybrids gave rise to fruit development, but only one produced viable seeds. The hybrids were tested for resistance to G. pallida pathotypes Pa2 and Pa3. A high level of resistance to Pa3, inherited from one parental clone, DHAK-11, and a high level of resistance to Pa2, inherited from the other parental clone, DHAK-33, was combined in four hybrids. These results demonstrate, that protoplast fusion is an efficient method for restoring the fertility of somatic hybrids generated from sterile parent clones, and is a powerful procedure for the complementation of multigenetic disease resistance traits in potato breeding lines. 相似文献
17.
Lean Han San Fernand Vedel Darasinh Sihachakr René Rémy 《Molecular & general genetics : MGG》1990,221(1):17-26
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. 相似文献
18.
Somatic hybridization is a potential method for gene transfer from wild relatives to cultivated crops that can overcome sexual
incompatibilities of two distantly related species. In this study, interspecific asymmetric somatic hybrids of Brassica oleracea var. botrytis (cauliflower) and Brassica nigra (black mustard) were obtained by protoplast fusion and their backcrossed (BC3) and selfed (S3) offspring were analyzed. Cytological analysis showed that the B. nigra chromosomes were successively eliminated in the backcrosses with cauliflower. The fertility of the hybrid progenies was quite
different due to the asynchronous and abnormal chromosome behavior of pollen mother cells (PMC) during meiosis. Analysis of
sequence-related amplified polymorphism (SRAP) showed that all of these hybrids mainly had the DNA banding pattern from the
two parents with some alterations. Genetically, the selfed generations were closer to B. nigra, while the backcrossed generations were closer to the cauliflower parent. Analysis of cleaved amplified polymorphic sequences
(CAPS) and restriction fragment length polymorphisms (RFLP) showed that all somatic hybrids in this study contained chloroplast
(cp) DNA of the donor parent black mustard, while mitochondrial (mt) DNA showed evidence of recombination and variations in
the regions analyzed. Furthermore, three BC3 plants (originated from somatic hybrids 3, 4, 10) with 2–8 B. nigra-derived chromosomes shown by genomic in situ hybridization (GISH) displayed a more cauliflower-like morphology and high resistance
to black-rot. These plants were obtained as bridge materials for further analysis and breeding. 相似文献
19.
Otto Schieder 《Planta》1978,141(3):333-334
The hybrid nature of tetraploid somatic hybrids of two genetically different chlorophyll-deficient mutants from Datura innoxia Mill. was demonstrated with the aid of anther culture. Green and chlorophyll-deficient androgenetic lines could be regenerated from the pollen grains. 相似文献
20.
E. Nenz F. Pupilli F. Damiani S. Arcioni 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(1-2):183-189
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. 相似文献