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1.
J. Keller 《Euphytica》1990,47(3):241-247
Summary Induction of haploid plants is of great importance for breeding purposes because of the possibility to obtain from haploids homozygous material by artificial chromosome doubling in relatively short times. The present study reports the first evidence of successfull haploid induction in onion. Isolated ovules, ovaries, or whole flower buds of different Allium species were cultured on BDS agar medium. Testa browning in the ovules and an extensive growth of the latter were observed. In cultures of ovaries and flower buds, development of callus and subsequent regeneration of plantlets from the region of the nectaries were observed. In leek, sometimes supernumerary flower organs like ovules were formed in this callus. In onion (Allium cepa L.), plantlets developed from the ovules in all culture methods. Chromosome numbers of these plantlets were counted in root tip squash preparations. They were found to be haploid. Haploid plants were significantly smaller than diploid ones. They were transferred to soil and developed until bulb formation. Because of their importance for breeding, haploid plants obtained by gynogenesis are further stored in vitro.  相似文献   

2.
Summary Variation in the capacity to regenerate shoots and morphogenetic potential were investigated by cyclic culture and regeneration of Nicotiana tabacum var. BEL W3. Explants were excised from different shoots formed by the same callus line. Differences in the organogenetic in vitro response among regenerated plantlets was observed in two subsequent regenerate generations. A progressive decrease of the regenerative capacity was observed across callus line generations.  相似文献   

3.
Summary An in vitro propagation of two genotypes of Begonia x hiëmalis was achieved through adventitious shoot formation on (sub)cultured leaf-disc explants and subsequent transplantation to soil of explant-parts with adventitious shoots.After irradiation of detached leaves with different doses of X-rays and two cycles of adventitious shoot formation on in vitro (sub)cultured leaf-disc explants, plantlets were produced. About 30% of these plants was mutated with respect to e.g. the colour, size and form of the leaves and flowers. The great majority of the mutants (98.5%) proved to be solid (non-chimeric).  相似文献   

4.
Summary Experiments upon in vitro culture of immature durum wheat embryos, harvested at different growth stages, were made in two consecutive years. Callus formation and plantlet regeneration were obtained. The ability to form callus and the degree of morphogenetic processes varied with the different hormonal treatments used and with the age of the embryos. In the first year the best response for callus growth was observed with 2,4-D 2 mg l-1 plus adenine 50 mg l-1 or 2,4-D 5 mg l-1 alone in the more mature embryos (15 and 20 days after anthesis). On the contrary, NAA 5 mg l-1 had a greater shoot regeneration effect. In the next year, at all 2,4-D concentrations and for the two different ages of the embryos tested, all embryos formed callus. Regeneration of plantlets was obtained in higher percentage in calli originated from the more developed embryos. The effect of changed media upon plantlet regeneration was studied after callus transplant.Investigation by cytophotometry and chromosome counts on different calli showed, practically in all cells, a diploid condition. A histological analysis demonstrated embryogenic somatic characteristics in many samples of callus. The pattern of organogenesis seemed to be via adventitious bud formation but structures resembling embryoids were also observed in the callus.  相似文献   

5.
Serge Gudin 《Euphytica》1993,72(3):205-212
Summary Two crosses between Rosa hybrida L. cultivars, that fail to produce progenies by conventional means, were carried out. In one of them, total hip abscision occured seven weeks after pollination; in the other one, only 2% of the fertilized hips remained on the plants after eleven weeks. Four- and five-week-old fertilized ovules were isolated in the first cross and six-week-old embryos in the second. The ovules were cultured on six media which differed in their mineral salt and sucrose concentrations while the embryos were cultured on only one of these media and eventually cold treated for one month at 4° C before being placed in a culture room set at 23° C. The embryos that had been isolated in ovulo when they were still not visible under a binocular lens developed atypically. The embryos isolated in ovulo when they were heart-shaped and on average 0.27 mm long performed in ovulo germination on some media and/or enlargement on all of them after two weeks; after another two week culture, once isolated from the ovule, all of them germinated. The cultured isolated embryos, that were exposed to cold, enlarged and germinated more rapidly when placed at 23° C than those not exposed to cold. Furthermore, the plantlets resulting from untreated embryo germination were characterized by large cotyledons which were only partially green. These results are discussed in regard to embryogenesis, precocious germination and dormancy.  相似文献   

6.
Brent Tisserat 《Euphytica》1982,31(1):201-214
Summary A discussion of a suitable procedure to rapidly propagate free-living date palms (Phoenix dactylifera L.) from callus cultures is presented. Embryogenic callus derived from lateral bud explants was subjected to various auxin treatments in liquid and agar media including p-chlorophenoxyacetic acid. -naphthaleneacetic acid or 2,4-dichlorophenoxyacetic acid at 0.0, 0.1, 1.0 and 10.0 mg/l concentrations in order to obtain optimum growth. Subsequent plantlet initiation from callus was found to be related to initial auxin pretreatments upon subculture to medium devoid of hormones. Plantlet production from callus subcultured from media containing 0.0, 1.0 and 10.0 mg/l auxin concentrations was notably lower than from callus precultured on the 0.1 mg/l auxin levels. In order to improve in vitro adventitious rooting isolated plantlets were cultured on media containing 0.0, 0.1, 1.0 and 10.0 mg/l concentrations of indole-3-acetic acid or -naphthaleneacetic acid in various physical environments. Optimum adventitious rooting responses and survival in free-living conditions were obtained by culturing plantlets in medium containing 0.1 mg/l for 8–16 weeks prior to transplanting to soil. Axillary shoot outgrowths (offshoots) were found to be common in plantlets cultured on a variety of media once an adequate root-shoot system was developed. Mention of a trademark name or proprietary product does not constitute a guarantee or warranty of the product by the US. Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.  相似文献   

7.
Summary Callus induction, callus growth and organogenetic processes were investigated in hypocotyl and stem cultures of four species of Amaranthus each of which comprised several varieties. Callus formation occurred in almost all the varieties in 100% of explants. The combinations of naphtaleneacetic acid plus benzylaminopurine or 2,4-dichlorophenoxyacetic acid plus Kinetin were very effective in causing callus formation; the results for callus growth in presence of the same growth regulator combinations revealed in some cases significant differences among the varieties.As far organogenesis-based on a few varieties-only A. caudatus and A. hypochondriacus responded well forming shoots from callus when cultured in presence of indoleacetic acid plus Kinetin and/or indoleacetic acid plus benzylaminopurine. Root regeneration was also observed in several varieties. Complete plantlets were obtained from rooted shoots.The results are discussed in relation to hormonal effect and the genotype importance.  相似文献   

8.
Summary A simple protocol for leaf rooting in beans (Phaseolus vulgaris L.) was developed and used to investigate the reaction of Xanthomonas campestris pv. phaseoli (Xcp), causal pathogen of common bacterial blight disease, in detached versus attached bean leaves. Trifoliate leaves of different sizes (one-third, two-thirds, and fully expanded), either with or without the pulvinus attached to the petioles, were excised from 20 day-old plants of six bean cultivars/lines. Leaf cuttings were cultured in potting medium and then incubated for 5 to 10 days under transparent polyethylene plastic cover in the greenhouse. Roots were readily initiated along the petioles of the leaf cuttings, whether the pulvinus was present or absent. All leaves which were two-thirds expanded and fully expanded developed roots 5 to 7 days after culture. Eighty to 90 percent of the leaves which were one-third expanded formed roots 8 to 10 days after incubation. Laminae of the rooted leaf cuttings were viable and green during the 2 to 3 months period in culture after removing the plastic cover. The common bacterial blight reactions were similar for inoculated attached leaves, detached rooted leaves (inoculated either after or prior to rooting), and moistened detached leaves incubated without rooting. The latter were only usable for evaluation of the Xcp reaction in growth chamber experiments but not under greenhouse conditions. The rooted leaves would be useful for screening bean lines for multiple disease resistance, especially if the pathogens require different environments for disease expression.Abbreviations CBB Common Bacterial Blight - Xcp Xanthomonas campestris pv. phaseoli (Smith) Dye  相似文献   

9.
Gitta Oettler 《Euphytica》1984,33(1):233-239
Summary One hexaploid wheat cultivar (Triticum aestivem) and two tetraploid wheat lines (T. durum) were crossed with seventeen inbred lines of rye (Secale cereale). Seed set, degree of hybrid embryo differentiation at the time of excision for in vitro culture and recovery of amphihaploid plantlets from various embryo categories were studied. Degree of embryo differentiation was predominantly determined by maternal wheats, paternal rye genotypes appearing to be of minor importance. T. aestivum x rye hybrid embryos were superior to those produced from T. durum for degree of differentiation. The proportion of plantlets developing from differentiated embryos was high for all wheat parents, whereas undifferentiated embryos were mostly unsuitable for plantlet production. The results revealed that cross-incompatibility in hexaploid wheat x rye crosses was due to failure of fertilization, while in tetraploid wheat x rye crosses it was caused by lack of embryo differentiation. Correlation analyses showed that seed set provided a criterion to predict the amphihaploid plantlets to be expected from a particular wheat x rye combination.  相似文献   

10.
J. R. Rout  N. P. Sarma 《Euphytica》1991,54(2):155-159
Summary Callus induction and green plant regeneration at high frequencies from an interspefic hybrid, Oryza sativa L. x O. rufipogon Griff. has been achieved by simply coordinating the growth regulators in the induction medium. The study was conducted with two different basal media (Potato-2 and N6) and seven different combinations of growth regulators 2,4-D, NAA and kinetin. Synergistic effects of the two auxins in enhanced anther response to callus induction and subsequent green plant regeneration were observed in both media. The highest frequency of callus induction was obtained on Potato-2 medium supplemented with 1 mg/12,4-D, 2 mg/l NAA and 1 mg/l kinetin. The same combination of growth regulators which yielded higher frequencies of callus induction also induced higher mean number of calli per anther. Although the calli formed on N6 medium showed high regenerability, there was a concomitant increase in the number of albinos among the regenerants. The auxins in the induction media had considerable influence on the regeneration capacity of the calli. The regeneration frequencies were higher from calli formed in the presence of both auxins in the induction media. The levels of growth regulator combinations seem to influence the green plant regeneration especially for calli induced on Potato-2 medium. Among the pollen grain derived plants the majority were either haploids or double haploids and very few were chromosomal variants.  相似文献   

11.
Summary A assessment of in vitro characters: embryo size, differentiation stage and germination time of haploid embryos, was carried out with a view to developing a selection procedure to increase the efficiency of doubled haploid (DH) production using the Hordeum bulbosum system. The differentiation stage of haploid embryos at the time of excision was found to be the most promising character for selection. In the two spring crosses examined 55% of excised embryos were undifferentiated and 45% were differentiated, with overall success rates, in terms of the percentage of DHs produced, of 7.91% and 25.16%, respectively. 17% of excised embryos produced callus. These embryos performed poorly in terms of regeneration and subsequent growth. It is suggested that only differentiated non-callusing embryos are maintained in order to maximize the efficiency of DH production. It is also shown that the overall success rate depends not only on initial stages such as seed setting but also on genotypic differences in response to colchicine treatment at later stages.  相似文献   

12.
Summary Fusarium solani f.sp. eumartii Carp. Snyder and Hansen (Fusarium eumartii) is a soil inhabitant that induces the so-called Potato Wilt and Stem End Rot disease. Prior to wilting, the pathogen induces peculiar small bronze spots on the leaflets. Failure to isolate F. eumartii from infected leaflets suggests the involvement of a toxin in the disease. The fungus was grown in liquid Richard's medium and thereafter a filtrate was obtained dialyzing (MW cutoff 12,000–14,000) and sterilizing the culture by filtration (0.22 m). Potato leaves treated with both the pathogen or the filtrate showed symptoms of bronze spots and significantly higher electrolyte leakage when compared to controls. Tomato leaves showed neither bronze spots nor electrolyte leakage after plant inoculation with the pathogen or with the filtrate treatment. Both, the absence of visible symptoms and the lack of electrolyte leakage in tomato could be associated to a certain degree of host specificity of the F. eumartii filtrate towards potato. The filtrate also induced symptoms similar to infections by F. eumartii in adult plants and in vitro plantlets of cultivars Huinkul MAG and Kennebec. Callus responses to the filtrate were related to responses of the cultivars to the pathogen in greenhouse. These results show the potential of the culture filtrate of F. eumartii for use in screening for wilting resistance.  相似文献   

13.
Felicitas Svejda 《Euphytica》1979,28(2):309-314
Summary Heritability in the broad sense and the distribution of levels of winterkill were analyzed in the offspring from hardy diploid and from hardy, semi-hardy and tender tetraploid roses. The heritabilities for different parental combinations ranged from 51 to 92%.The offspring from crosses of hardy parents were also hardy and showed little variation in hardiness levels. The offspring from crosses of hardy roses with the semi-hardy R. kordesii and the tender Queen Elizabeth survived the winters without coverage but showed a wider variation in hardiness levels.The desirable level of hardiness, an average winterkill of less than 10%, could be achieved through selection in the first or second generation of breeding, depending on the hardiness levels of the parents. The hypothesis is advanced that winterhardiness in roses is controlled by very few or closely linked genetic factors.Contribution No. 557  相似文献   

14.
F. Diaz  N. Jouve 《Euphytica》1986,35(1):129-135
Summary The electrophoretic isozyme phenotypes for the AAT-2 and AAT-3 regions of leaves of Triticum turgidum, T. aestivum, Secale cereale, x Triticosecale (hexaploid) and T. aestivum/ S. cereale 6R addition line are described. The phenotypes varied in distribution and relative intensity of the isozyme bands, which were densitometrically measured. The results are consistent with a hypothesis of the dimeric structure for the AAT-2 and AAT-3 systems.  相似文献   

15.
B. S. Ahloowalia 《Euphytica》1982,31(3):755-759
Summary A procedure for plant regeneration from callus culture of potato, Solanum tuberosum L. is described. Calli were induced from 1–2 mm long shoot apices of potato cultivars Cara and A25/19 on half-strength Murashige and Skoog's medium (half-MS) supplemented with 3.2 mg IAA (indole-3-acetic acid), 1.0 mg kinetin (6-furfurylamino)purine], and 0.5 mg 2,4-D [2,4-dichlorophenoxy)acetic acid]/1. Sixty percent explants produced nodular calli on this medium within 30 days. Calli differentiated into shoot-primordia when subcultured on half-MS medium supplemented with 0.5 mg 2,4-D and 1.0 mg zeatin [6-(4-hydroxy-3-methybut-2 enylamino)amino purine]/1. Differentiated calli on half-MS medium without growth hormones produced complete plantlets which were cloned on the same medium and transferred into soil.  相似文献   

16.
Summary Daylily plantlets with tetraploid or octaploid chromosome numbers were induced from colchicine-treated diploid callus (2n=22). Callus tissue of the daylily Hemerocallis flava L. was placed on a morphogenetic induction medium, a modified MS formula supplemented with 1 mg 2,4-D and 1 mg kinetin/liter, plus 0,10, 20, or 40 mg/liter colchicine in the dark at 12°C for 3 days and recuperated for 1 week under the same environmental conditions except that colchicine was left out. The calluses were then returned to the normal growth temperature 25°C. Ploidy was identified by chromosome counts of squashed root-tip cells collected from the newly potted plantlets and later by measurements of stomates and pollen grains. Over 50% of the plants initiated from the colchicine-treated calluses were completely tetraploid. All of the plantlets differentiated from untreated callus had a diploid number of 22. Of the 3 colchicine levels applied, the 20 mg/liter treatment appeared to be the most effective in production of tetraploidy.  相似文献   

17.
Summary Parts of Saintpaulia ionantha leaves were cultured on a medium supplemented with different concentrations of colchicine or caffeine. The explants were transferred to a control medium without these chemicals after different periods of time. The chromosome number of the regenerated plantlets was counted. In all the experiments, polyploid plantlets were found, but the percentage of them was higher with colchicine. There were no differences in frequency of polyploid plantlets among treatments with the same chemical. In both cases a high percentage of cytochimeric plantlets was observed and possible explanations of their occurrence are given.  相似文献   

18.
The time course of cannabinoid accumulation in the leaves of individual plants of three Cannabis accessions was determined by gas-chromatographic analysis in greenhouse-grown plants. The total amounts and the concentration ratios of CBD, THC and CBG were determined; two accessions (an experimental hybrid, (21R × 15R) × NL, and plants from a seized seed lot) were found chemotypically uniform, with all plants belonging to chemotpe II (mixed) and I (high THC) respectively. The Carmagnola accession showed chemotypic heterogeneity, with a majority of plants belonging to chemotype III. The CBD/THC and CBG/CBD ratios were shown to be largely constant in the leaves, since 28 and until 103 days after sowing, and consistent with the ratios determined on mature inflorescences. CBD and THC maximum amounts in the leaves showed a peak in the leaves around 80 days from sowing, and were shown to be simultaneous during the growth period, irrespective of the chemotypes. Callus cultures were obtained from all the five different chemotypes (I, II, III, IV, V), and GC analyses were performed. Independently of the type and amount of cannabinoids in the mother plants, it was confirmed that callus cultures of Cannabis were not able to produce detectable amounts of any cannabinoids.  相似文献   

19.
Summary Interspecific hybrids betweenLimonium perigrinum andL. purpuratum were obtained usingL. perigrinum as the female parent. No hybrids were produced by the reciprocal cross. Twelve- to 15-day-old embryos were rescued and cultured within their embryo sacs on modified B5 or KM medium. After two to three days the embryos were excised from their embryo sacs and re-plated on to fresh medium. When the embryo-derived plantlets had attained a length of 1 cm they were transferred to a modified MS medium containing BA and NAA for shoot proliferation. Plantlets were transferred to modified MS medium supplemented with IBA for 24 hours for root initiation then to a modified growth-regulator-free MS medium for root growth. After a further 28 days the plantlets were transferred to soil-less medium for acclimatisation. The hybrid characteristics of one of the 15 embryo-derived plants were determined by flow cytometry and by examination of morphological features. The mean DNA contents of 2C nuclei fromL. perigrinum, the hybrid andL. purpuratum were 13.98 pg, 16.81 pg and 19.37 pg, respectively. Mitotic and meiotic chromosome counts fromL. perigrinum andL. purpuratum showed that both parents and their hybrids had identical chromosome numbers (2n=24), and that the species were closely related. Morphological analyses of leaves and flowers showed that the hybrids displayed a number of features intermediate between both parents.Abbreviations B5 Gamborg et al. (1968) B5 medium - BA benzyl adenine - IBA indole-3-butyric acid - KM Kao and Michayluk (1975) medium - MS Murashige and Skoog (1962) medium - NAA napthalene-1-acetic acid - PVP polyvinylpyrrolidone  相似文献   

20.
A fully fertile interspecific hybrid (Cucumis hytivus Chen and Kirkbride, 2n =4x =38) between Cucumis hystrix Chakr. (2n= 2x =24) and C. sativus L. (2n = 2x = 14) was previously produced by means of F1 (2n = 19) embryo rescue and subsequent chromosome doubling. This amphidiploid, a new synthetic species, may serveas a genetic bridge in Cucumis, and thus is a source for broadening the genetic base of C. sativus. The identification and characterization of fertile progeny possessing lower ploidy levels would facilitate bridging among Cucumis species. Putative allotriploids (2n = 26) were recovered from C. hytivus × C. sativus matings by means of embryo culture, and experiments were designed to confirm their genetic constitution, describe their morphology, and establish an efficient protocol for their micropropagation. Apical and axillary buds of these putative allotriploid plants were used as explants to establish a micropropagation system for subsequent verification and characterization of ploidy. Of the array of micropropagation media tested, then ability to be most effective for the induction of adventitious buds (desginated Stage II) was a Murashige and Skoog (MS)growth media containing 13.3μM BA + 1.1μM NAA or containing10 μm BA only. The mean number of adventitious buds per explant in the two media was 6.8 and 6.5, respectively. Shoots resulting from adventitious buds produced roots (Stage III) in relative abundance (39 of 42, 92.8%) on half-strength MS medium containing 1.0 μm IBA. The survivorship of rooted plantlets after acclimatization as assessed by relative production of leaves in plantlets (designated Stage IV) was 91.4% (148 of 162). The chromosome number in putative allotriploid plants as determined in mitotic root tip figures in all plants was 2n = 26, the number expected for allotriploids derived from such a mating. An examination of pollen viability in five samples of each plant by cytochemical staining revealed stainability to be < %.Compared to their parents, the allotriploid genotypes possess a high degree of parthenocarpy (84.8%) as measured by setting fruit in pollen-free conditions. While allotriploid fruit are black-spined and similar to the maternal parent C. hytivus, the dark green leaves typical of allotriploid plants mirrors that of the paternal C. sativus parent. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

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