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1.
Summary Employing in vitro culture of ovaries, ovules and embryos, interspecific hybrids have been obtained amongst two important oilseed crops, Brassica napus x B. juncea and their reciprocal. The test-tube hybrid plants have been transferred to the field, and reared to maturity. The F1 seeds obtained from the hybrid ovaries showed normal germination, and the hybrid plants exhibited a range of variation of characters. 相似文献
2.
Summary The risk for a gene dispersal is reported for reciprocal crosses between a transgenic rapeseed variety resistant to the herbicide phosphinotricin and five related species. The first stages after pollination were cytologically observed and fertilized ovaries were established in in vitro culture for the production of interspecific hybrids. A similar classification was observed for the index of pollination compatibility and embryo yield. From the 243 embryos produced, 109 plantlets were obtained in a greenhouse. All the interspecific combinations tested were able to produce hybrid plants. A higher number of hybrids was obtained when rapeseed was used as the female parent. The hybrids had the expected triploid structure except for two amphidiploid, B. napus × B. oleracea, and one amphidiploid, B. napus × S. arvensis, plants with 56 chromosomes. The triploid hybrids were sterile or partially fertile but two of the amphidiploid plants, B. napus × B. oleracea, were fully fertile. The cytoplasm source did not seem to affect the fertility of the hybrids. 相似文献
3.
Summary Atrazine resistant Brassica napus × B. oleracea F1 hybrids were backcrossed to both parental species. The backcrosses to B. napus produced seeds in both directions but results were much better when the F1 hybrid was the pollen parent. Backcrosses to B. oleracea failed completely but BC1s were rescued by embryo culture both from a tetraploid hybrid (2n = 4x = 37; A1C1CC) and sesquidiploid hybrids (2n = 3x = 8; A1C1C). Progeny of crosses between the tetraploid hybrid and B. oleracea had between 25 and 28 chromosomes. That of crosses between the sesquidiploid hybrid and B. oleracea had between 21 and 27. A few plants that had chromosome counts outside the expected range may have originated from either diploid parthenogenesis, unreduced gametes or spontaneous chromosome doubling during in vitro culture. Pollen stainability of the BC1s ranged from 0% to 91.5%. All the BC1s to B. oleracea were resistant to atrazine. 相似文献
4.
A successful interspecific hybridization between cucumber (Cucumis sativus L., 2n = 14) and a wild it Cucumis species, C. hystrix Chakr. (2n = 24) was made via embryo rescue. Hybrid plants (2n = 19; 7 from cucumber and 12 from C. hystrix) were sterile, but morphologically uniform. Self-pollination and backcrossing of F1 hybrid plants to either parent confirmed presence of both male- and female-sterility that were likely caused by lack of homology
and improper pairing during meiosis. While the multiple-branching habit, densely brown hairs (on corolla and pistil), orange-yellow
corolla, and ovate fruit of F1 hybrid plants were similar to that of the C. hystrix parent, the appearance of the first pistillate flower was more similar to that of C. sativus parent. The diameter and internode length of the stem, and the shape and size of leaves and flowers were intermediate when
compared to the parents. The chromosome number in the hybrid was doubled through somaclonal variation during embryo culture
and regeneration process to restore the fertility. Pollen grains were released and fruits with viable seeds matured on fertile,
synthetic amphidiploid plants. The results from flow cytometry indicated that, on average, 7.3% of the morphologically unique
regenerants had the 4C DNA content of 2.35 pg relative to the 2C DNA content of the original F1 hybrid at 1.17 pg and, therefore, were likely chromosome-doubled F1 hybrids (2n = 38). Nutrition alanalysis indicated that the synthetic species had higher protein (0.78%)and mineral (0.35%)
content compared to the normal pickling cucumber(0.62% and 0.27%, respectively), and could be considered a new Cucumis crop having a special place in the future agriculture. Preliminarily evaluation indicates that C. hystrix possesses a high level of root-knot nematode resistance, and that this resistance is partially expressed in the interspecific
F1 and chromosome-doubled F1. This and the fact that the fruit morphology of the fertile amphidiploid differs during the growing season (e.g., short and
long fruit) suggest that it could be useful in broadening the germplasm base of cucumber.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
Wheat-barley translocations were identified by genomicin situ hybridization (GISH) in backcross progenies originating from in vitro regenerated wheat (Triticum aestivum L. cv. Chinese Spring) × barley (Hordeum vulgare L. cv. Betzes) hybrids. The regenerated hybrids were pollinated with the wheat line Martonvásári 9 kr1. Five translocated
wheat-barley chromosomes were recovered among 51 BC2F2 progeny from the in vitro regenerated wheat × barley hybrids. All were single breakpoint translocations with the relative positions of the breakpoints
ranging from the centromere to about 0.8 of the relative arm length. Of the four translocations with intercalary breakpoints,
three were transfers of terminal barley segments to wheat chromosomes; one was a transfer of a terminal wheat segment to a
barley chromosome. Because of the absence of diagnostic N-bands, the identity of three barley segments could not be determined;
in one translocation the barley chromosome involved had a NOR so it must have been 5H or 6H, and the centric translocation
was 4HS.2BL. Following selfing, homozygotes of four translocations were selected. The experiment suggests that in vitro culture conditions are conducive for major genome rearrangements in wheat-barley hybrids.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Nobumichi Inomata 《Euphytica》1993,69(1-2):7-17
Summary Crossability and cytology were examined in F1, F2, B1 and hybridsplants of F1 hybrids of Brassica campestris and three wild relatives of B. oleracea, B. bourgeaui, B. cretica and B. montana, respectively. The F2 plants were obtained after self-and open pollination of the F1 hybrids. The B1 and hybrid plants were produced after the F1 hybrids backcrosses with B. campestris and crossed with B. napus, respectively. After crossing the F1 hybrids, many seeds of the F2, B1 and hybrid plants were harvested. Multivalent formation was high in the chromsome configuration for the PMCs of F2, B1 and hybrid plants, suggesting that crossing over might occur between them. Many different types of aneuploids were obtained in the progenies of the F2, B1 and hybrid plants. It is suggested that different types of normal egg cells may be produced by one-by-one or little-by-little chromosome addition. The possibility is discussed of gene transfer from B. bourgeaui, B. cretica and B. montana, to cultivated plants, B. campestris and B. napus. 相似文献
7.
Summary Interspecific hybrids have been obtained in an otherwise incompatible cross betweenBrassica juncea × Brassica hirta through the in vitro culture of hybrid ovules and ovaries. The best response was observed from ovules and ovaries cultured 10–15 and 5–7 days after pollination respectively on a basal medium supplemented with indoleacetic acid, kinetin and casein hydrolysate. In some cases the basal cut end of the ovaries proliferated to form callus and shoots. The in vitro-derived hybrid seeds varied in their colour, size and shape, and the F1 plants in the field showed a large diversity in their morphological traits. The hybrids were sterile, and had an intermediate number of chromosomes (2n=30). 相似文献
8.
Three segregating F2 populations were developed by self-pollinating 3 black rot resistant F1 plants, derived from across between black rot resistant parent line 11B-1-12 and the susceptible cauliflower cultivar ‘Snow
Ball’. Plants were wound inoculated using 4 isolates ofXanthomonas campestris pv. campestris (Xcc) race 4, and disease severity ratings of F2 plants from the three populations were scored. A total of 860 arbitrary oligonucleotide primers were used to amplify DNA
from black rot resistant and susceptible F2 plants and bulks. Eight RAPD markers amplified fragments associated with completely disease free plants following black rot
inoculation,which segregated in frequencies far lower than expected. Segregation of markers with black rot resistance indicates
that a single, dominant major gene controls black rot resistance in these plants. Stability of this black rot resistance gene
in populations derived from 11B-1-12 may complicate introgression into B. oleracea genotypes for hybrid production.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Summary Intergeneric hybrids (F1) Diplotaxis erucoides (DeDe) x Brassica napus (AACC) and the first backcross to B. napus (BC1) have been obtained through in vitro culture of excised ovaries. The chromosome numbers of F1 and BC1 plants proved the occurrence of unreduced gametes. The study of metaphase I chromosome pairing showed that autosyndesis in De genome and allosyndesis between De and A/C genomes might exist. The male fertility of the F1 plants was low. Some male-sterile plants were found in F1 and BC1 progeny. The possibilities of creating addition lines B. napus-D. erucoides and of obtaining a new cytoplasmic male sterility in B. napus are discussed. 相似文献
10.
Summary Hybridization between radish and oilseed rape has been cumbersome, requiring elaborate embryo rescue techniques. With a modified flower culture method, we have achieved successful hybridization between radish and (transgenic) oilseed rape without the laborious and technically demandingin vitro ovule or embryo rescue techniques.The hybrid nature of the intergeneric hybrids was demonstrated using morphological traits, and DNA analyses. The described method will facilitate the generation ofRaphanobrassica hybrids useful for biosafety studies of the potential for transgenes to spread in weedyCruciferae as well as for breeding programs aimed at introducing useful radish genes, e.g. nematode resistance genes, into oilseed rape. 相似文献
11.
The genetics of resistance to Phomopsis stem blight caused by Diaporthe toxica Will., Highet, Gams & Sivasith. in narrow-leafed lupin (Lupinus angustifolius L.) was studied in crosses between resistant cv. Merrit, very resistant breeding line 75A:258 and susceptible cv. Unicrop.
A non-destructive glasshouse infection test was developed to assess resistance in the F1, F2, selected F2-derived F3 (F2:3) families, and in selfed parent plants. The F1 of Unicrop × 75A:258 (and reciprocal cross) was very resistant, and the F2 segregated in a ratio of 3:1 (resistant: susceptible), which suggested the presence of a single dominant allele for resistance
in 75A:258. In Merrit × Unicrop (and reciprocal), the F1 was moderately resistant, and the F2 segregated in a ratio of 3:1 (resistant: susceptible). Thus Merrit appeared to carry an incompletely dominant resistance
allele for resistance. The F1 of Merrit × 75A:258 (and reciprocal) was very resistant and the F2 segregated in a ratio of 15:1 (resistant: susceptible), which supported the existence of independently segregating resistance
alleles for resistance in 75A:258 and Merrit. Alleles at loci for early flowering (Ku) and speckled seeds (for which we propose the symbol Spk) segregated normally and independently of the resistance alleles. Resistant F2 plants gave rise to uniformly resistant or segregating F2:3 families, whereas susceptible F2 plants gave rise only to susceptible F2:3 families. However, the variation in resistance in the F2 and some F2:3 families of crosses involving 75A:258, from moderately to extremely resistant, was greater than that expected by chance or
environmental variation. We propose the symbols Phr1 to describe the dominant resistance allele in 75A:258, and Phr2 for the incompletely dominant resistance allele in Merrit. Phr1 appears to be epistatic to Phr2, and expression of Phr1 may be altered by independently segregating modifier allele(s).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
Summary The first backcross and F2 progenies from triploid F1 and tetraploid F1 hybrids between B. napus and 2x and 4x B. oleracea ssp. capitata (cabbage) were studied for their general morphology, resistance to race 2 of the clubroot pathogen, chromosome number and meiotic chromosome behavior. No linkage was apparent between resistance and the major morphological characters. Unreduced gametes played a large part in the successful formation of seed of the B1 and F2 progeny. B1 plants with low chromosome numbers were selected for use in recurrent backcrosses. The potential use of anther culture to extract gametic progenies from resistant B1 and F2 plants with higher chromosome numbers was suggested. The presence of homoeologous pairing observed in all the plants is considered advantageous for selecting suitable progeny in later generations. 相似文献
13.
Downy mildew, incited by Peronospora parasitica (Pers.: Fr.) Fr., is a destructive disease of broccoli (Brassica oleraceaL., Italica Group). Resistant cultivars represent a desirable control method to provide a practical, environmentally benign,
and long-term means of limiting damage from this disease. Doubled-haploid (DH) lines developed by us exhibit a high level
of downy mildew resistance at the cotyledon stage. To determine the mode of inheritance for this resistance, a resistant DH
line was crossed to a susceptible DH line to make an F1, from which F2 and backcross (BC) populations were developed. All populations were evaluated for response to artificial inoculation with
P. parasitica at the cotyledon stage. All F1 plants (including reciprocals) were as resistant as the resistant parent, indicating no maternal effect for this trait. F2 populations segregated approximately 3resistant to 1 susceptible, BC populations using the resistant parent as the recurrent
parent contained all resistant plants, and the BC to the susceptible parent segregated 1 resistant to 1 susceptible. These
results indicate that resistance is controlled by a single dominant gene. This gene should be easily incorporated into F1 hybrids and used commercially to prevent downy mildew at the cotyledon stage.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
14.
Summary Some plants without pods but with gynophores were observed in two F4 progenies of two crosses of goundnut (Arachis hypogaea L.). The flowers on these plants had translucent white anthers with no or a few sterile pollen grains. Three such plants in the succeeding generation were hand pollinated with pollen from a short-duration Indian cv. JL 24. The resulting F1 hybrid plants (male sterile x JL 24) were normal. Chi-square tests for segregation for male fertile and male sterile plants in F2 and F3 generations indicated that the male sterility in these crosses of groundnut is governed by two recessive genes. We designate these genes as ms1 and ms2 with ms1ms1ms2ms2 being a male sterile genotype.Submitted as ICRISAT J. A. No. 1812. 相似文献
15.
Summary Resistance to fusarium wilt, incited by Fusarium oxysporum (Schlecht.) f. sp. lycopersici (Sacc.) Snyder & Hansen race 3 in tomato (Lycopersicon esculentum Mill.) was discovered in LA 716, a L. pennellii accession. A resistant BC1F3 breeding line, E427, was developed from LA 716. E427 was crossed with the susceptible cv. Suncoast and F1, BCP1, BCP2 (to Fla 7155, a susceptible parent) F2, F3, and BCP2S1 seeds were obtained. Segregation for resistance following root dip inoculation over three experiments indicated a single dominant gene controlled resistance. Five of the 12 BCP1S1's segregated more susceptible plants, whereas one of the 12 segregated more resistant plants than expected (P<0.05). Three of 23 F3 lines segregated more susceptible plants than expected while 1 of the 23 had more resistant plants than expected (P<0.05). Segregation in all other lines fit expected ratios. Five of the 23 F3's were homozygous resistant which was an acceptable fit to expectations (P=0.1–0.5). The gene symbol I
3 is proposed for resistance to race 3 of the wilt pathogen. Deviations from expected ratios in data reported here and for other breeding lines indicate an effect of modifier genes and/or incomplete penetrance. Plant age at inoculation and seed dormancy did not affect results.Florida Agricultural Experiment Station Journal Series No. 8101. 相似文献
16.
Summary Powdery mildew development was assessed on squash (Cucurbita pepo) plants of a susceptible cultivar, a resistant accession, their F1, and their F2 in an early summer planting in the field, covered or not covered with a shading net. Three reaction types were observed: susceptible, powdery mildew on stems and on both, the upper and lower leaf surfaces, as in the susceptible parent; resistant, no powdery mildew on leaves or stems, as in the resistant parent; and partially resistant, powdery mildew on upper leaf surfaces only, as in the F1. Disease presence on the stem was associated with susceptibility. Shading hastened the appearance of powdery mildew and increased the severity of infection on partially resistant and susceptible plants, facilitating identification of resistant individuals in the F2 population.Contribution No. 1613-E from the Agricultural Research Organization, Bet Dagan, Israel 相似文献
17.
S. Tokumasu 《Euphytica》1976,25(1):463-470
Summary Amphidiploids (Brassicoraphanus) were produced by means of colchicine treatment of F1 hybrids between Brassica japonica
Sieb. and Raphanus sativus L. The cytology of the amphidiploids was studied from F1 to F3 generations. Some plants had the euploid chromosome number 2n=38, whereas others had the aneuploid number 2n=37. One or two of either quadrivalents or trivalents, as well as some univalents, were seen in most of the plants examined. All the plants showed a low seed fertility. In F3 generation there arose some yellow-flowered plants, all of which showed a higher seed fertility than normal white-flowered plants. It is postulated that the change of flower colour might originate in the segmental exchange of only partially homologous chromosomes following multivalent formation. A gene causing white flower colour was perhaps closely linked to a gene causing sterility, and both genes were probably excluded together through the segmental exchange of the chromosomes. Therefore, it can be said that the increase of fertility was induced by cytological irregularity. 相似文献
18.
N. Inomata 《Euphytica》2005,145(1-2):87-93
Brassica napus (2n = 38) and Diplotaxis harra (2n = 26) were used to investigate gene transfer from D. harra to B. napus. Intergeneric F1 hybrids (dihaploid 2n = 32 chromosomes) were obtained through ovary culture. The chromosome associations in the first meiotic division was (0–2)III + (2–10)II + (12–28)I. Many seeds were harvested in the F1 hybrid after backcrossing with B. napus, and from open pollination of the F1 hybrid. Somatic chromosome numbers of BC1 and hybrid plants varied from 2n = 26 to 52. In the first meiotic division, high frequencies of bivalent association and relatively low pollen fertility were
observed. BC2 plants generated from the BC1 plants with 2n = 38 chromosomes, 69.6% showed 2n = 38 chromosomes. Many aneuploids with addition and deletion of chromosomes were also obtained. A bridge plant between B. napus and D. harra with 2n = 32 chromosomes should be valuable material for the breeding of brassica crops. 相似文献
19.
Summary Wide hybridizations between M. arvensis and Brassica amphidiploid species (B. napus and B. juncea) were carried out in order to incorporate desirable traits of M. arvensis into Brassica crops. Crossing barriers between them were present without the use of in vitro techniques. F1 hybrids have been produced through ovary culture, when M. arvensis were used as a female parent. Higher hybrid embryo productivity (3.07 embryos per pollination) was obtained in the cross of M. arvensis x B. napus than in that of M. arvensis x B. juncea (0.79 embryos). The hybridity was confirmed by morphology, cytology, isozyme and Southern analyses. The first backcrossing progenies and open pollinated ones were produced. 相似文献
20.
Summary Cross-incompatibility between cultivated peanuts and their wild relatives outside the section Arachis has impeded the utilization of many species possessing high resistances or good qualities. Despite the great efforts made to culture immature ovules or embryos, few hybrid offspring have been obtained. In this study, gynophores from Arachis hypogaea L. pollinated with A. glabrata Benth. were cultured and F1 hybrids seeds were harvested, and F2 and F3 generations produced. The characters of F2 generation exhibited a wide range of segregation. Leaf peroxidase isozyme PAGE analysis revealed that the hybrids were quite different from their parents in relation to band number, width and isozyme activity. The zymograms of the hybrids and their parents were partially alike. This verified the authenticity of the hybrids. 相似文献