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1.
Summary To examine whether chromosome numbers of Brassicoraphanus (amphidiploids between Brassica japonica
Sieb. and Raphanus sativus L.) are stable or not, the following four items were studied with some plants during the 2nd–11th generations: (1) chromosome numbers of open-pollinated progenies from eu-, hyper-, and hypoploids, (2) chromosome distribution at metaphase II in these plants, (3) frequency of euploids in relation to flower colour and generation, (4) seed fertility in eu-and aneuploids in relation to flower colour. In early generations, hyper-and hypoploids were frequently produced from euploids. In later generations, however, the chromosome number became less unstable. In euploids (2n=38), chromosome numbers at metaphase II showed some variation, and the mean frequency of the euploid chromosome number (n=19) was approximately 78%. This value was almost the same in white-and yellow-flowered plants through early and late generations. Nevertheless, yellow-flowered plants tended to produce euploids more frequently than did white-flowered ones. It is assumed that the difference in euploid productivity between yellow-and white-flowered plants is due to the difference in seed fertility between them. The progeny of each hypoploid showed higher chromosome numbers than their parents. The progeny of each hyperploid showed lower chromosome numbers than their parents: they were approaching to euploidy. This phenomenon, together with higher fertility of euploids and lower fertility of aneuploids, will favor the maintenance of euploidy of this strain. 相似文献
2.
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
3.
Summary Triazine resistant Brassica napus ssp. oleifera and ssp. rapifera were hybridized to cultivars of B. oleracea ssp. italica, ssp. botrytis, ssp. capitata and ssp. fimbriata. The interspecific embryos did not survive in vivo but could be rescued in vitro using a culture medium developed by Monnier (1973). The embryos did not grow directly into normal plants but were successfully regenerated using the protocol developed by Keller (1984). Hybridization efficiency ranged from 0 to 2.64 hybrids per pollination. Interspecific embryo abortion may be related to abnormal endosperm development. 相似文献
4.
Summary The 6×6×4 analysis of variance of the mean percentage embryo survival for six variegated cultivars of Pelargonium × hortorum Bailey, with mutant plastids in their germ layers, and for their isogenic green (G) clones, shows highly significant differences between females (81 to 91 per cent) and between plastid crosses (83 to 91 per cent). Between cultivar differences are attributed largely to additive effects corresponding to additive gene action, and between plastid differences to a lower survival after crosses with white (W) males than with green males. The relationship between overall fertility (% fertilization × survival) and plastid crosses is a stepwise decline in the order G×G>G×W>W×G>W×W (28 to 19 per cent) in which the white embryos growing in a white mother are approximately 30 per cent less fertile than the green embryos in a green mother. The non-surviving embryos are classified into empty, undeveloped and dwarf embryos and submitted to a 6×4 analysis of variance after summing through males. The significant heterogeneity between females is attributed largely to a difference between one cultivar-with a high frequency of dwarf and a low frequency of undeveloped embryos-and the other five cultivars. The absence of a significant plastid effect upon any stage of embryo breakdown indicates that the depressive effect of white plastids is spread evenly throughout development. 相似文献
5.
Summary Nucleus substitution of Brassica japonica (2n=20) with Raphanus sativus (2n=18) was carried out by means of repeated backcrossing of Brassicoraphavus (2n=37) to R. sativus as a pollen donor. In the course of nucleus substitution, chlorophyll deficiency appeared. Plants with more than 28 chromosomes, like their parents, had green leaves and those with 24 to 26 chromosomes had yellowish green ones. Almost all plants with 18 to 23 chromosomes showed yellow or whitish yellow. The R. sativus with B. japonica cytoplasm (2n=18) was obtained after four successive backerosses. The completely substituted R. sativus showed the same fertility as the true R. sativus used as a recurrent parent. It is assumed that the chlorophyll deficiency is caused by disharmony between the B. japonica cytoplasm and the R. sativus nucleus. The chlorophyll deficiency is discussed in comparison with male sterility or other characters which sometimes occur in alloplasmic Raphanus and Brassica species. 相似文献
6.
Summary In the synthesis of primary hexaploid triticale, a cross-incompatibility barrier exists when tetraploid wheat (4X) is crossed with diploid (2X) rye. Fertilization may occur, however, abnormal endosperm development usually leads to premature embryo death. Four selected tetraploid wheat lines were crossed as females with seven open-pollinated rye lines and the resulting embryos were rescued in vitro 13–16 days after pollination. The wheat genotypes showed a major influence on crossability (seed set), embryo development and plant recovery. The highest efficiency of amphihaploid plant recovery (18.3 plants per 100 pollinated florets) was obtained from one 4X wheat line originally selected from the cross T. carthlicum × T. dicoccoides. Some of the 3X amphihaploid plants (ABR) derived from two wheat lines showed relatively high level of partial fertility presumably as a result of meiotic restitution. Correlation analysis showed that crossability (seed set), normal hybrid embryo development in vivo and embryo culturability were independent of each other. 相似文献
7.
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
8.
Independent Inheritance of Erucic Acid Content and Flower Colour in the C-Genome of Brassica napus L. 总被引：3，自引：1，他引：3
The synthetic Brassica napus L. line No7076 was obtained from a cross between yellow-flowered and zero-erucic turnip rape (B. campestris) Sv85-38301 and white-flowered and high-erucic (41.4%) B. oleracea ssp. alboglabra No6510. This synthetic B. napus is pale-flowered and has an average erucic acid content of 25.8 %. It was crossed with the yellow-flowered and zero-erucic B. napus line SvS4-2S053 and segregation of the erucic acid content and flower colour was studied in F1 and F2 generations. The high erucic acid content was controlled by a single gene in the C-genome and was additively inherited. Strong evidence was obtained in support of independent segregation of the erucic-arid content and the flower colour characters controlled by the C-genome of B. napus. 相似文献
9.
Summary
Cajanus platycarpus, an incompatible wild species from the tertiary gene pool of pigeonpea (C. cajan (L.) Millspaugh), has many desirable characteristics for the improvement of cultivated varieties. To necessitate such transfers, embryo rescue techniques were used to obtain F1 hybrids. The F1 hybrids were treated with colchicine to obtain tetraploid hybrids, that were selfed to obtain F2, F3 and F4 progenies. All of the hybrids and subsequent progenies had an intermediate morphology between the two parents. Backcrossing of the tetraploid hybrids with cultivated pigeonpea was not possible given embryo abortion, with smaller aborted embryos than those obtained in the F0 parental cross.As a route of introgression, diploid F1 hybrids were backcrossed with cultivated pigeonpea and BC1 progeny obtained by in vitro culture of aborting embryos. BC2 plants were obtained by normal, mature seed germination. Although embryo rescue techniques had to be used to obtain F1 and BC1 plants, it was possible to produce BC2 and subsequent generations through direct mature seed. Every backcross to cultivated pigeonpea increased pollen fertility and the formation of mature seeds.Special project assistant till December, 2003. 相似文献
10.
Summary In order to elucidate the mechanism of low fertility of Brassicoraphanus, i.e., amphidiploids between Brassica japonica Sieb. and Raphanus sativus L., the chromosome number of 253 plants was studied during the 3rd–9th generations for their seed fertility. Meiotic irregularity showed no connection with degree of sterility. Brassicoraphanus consisted of euploids (2n=38), hyperploids (2n=39–43) and hypoploids (2n=34–37) with white or yellow flowers. The number of plants was highest in euploids and became lower as the chromosome number diverged from the euploid number. Further, seed fertility was highest and the range of its variation widest in euploids. The seed fertility of aneuploids became lower and its variation narrower in proportion to the number of chromosomes additional to or missing from the euploid number. Yellow-flowered plants were superior in seed fertility to white-flowered plants. Seed fertility of plants is primarily affected by their chromosome numbers and secondarily modified by genic effects. As a whole, seed fertility of Brassicoraphanus increased gradually and its variation widened with the advance of generations. This was explained mainly by the increase of balanced combinations of genes. 相似文献
11.
Relationship between sprouting in wheat and embryo response to endogenous inhibition 总被引：3，自引：0，他引：3
Summary Seed dormancy in wheat (Triticum aestivum L. em Thell) is important for minimizing pre-harvest sprouting. To facilitate breeding cultivars that tolerate pre-harvest sprouting conditions, we assessed mode and magnitude of variation of seed dormancy among genotypes and investigated involvement of endogenous water-soluble inhibitor(s) in seed germination. Embryo bio-assays established that water-soluble inhibitor was ubiquitous among the wheat cultivars studied and did not diminish in quantity during after-ripening. Germination response of embryos was decreased by endogenous inhibitor, but the effect markedly declined as embryos aged at room temperature. Variation in dormancy among cultivars was primarily caused by differential response of their embryos to endogenous inhibitor. Gibberellic acid counteracted the initial inhibitory effect of endogenous inhibitor on germination but not the subsequent inhibitory effect on seedling growth. We concluded that pre-harvest sprouting resistance involves multiple factors, particularly embryo receptivity to endogenous inhibitor, and that variation in inhibitor quantity is not solely responsible for genotypic differences in susceptibility to pre-harvest sprouting. The possibility of additional approaches to breeding for pre-harvest sprouting resistance is indicated.Contribution no. 81-389-j, Department of Agronomy, Kansas State University, Manhattan, KS 66506, U.S.A. 相似文献
12.
In order to identify the markers linked to microspore embryogenic ability in Brassica crops, RAPD segregation analyses were performed in a microspore-derived (MD) population and a F2 population derived from F1between ‘Ho Mei’ (high responsive parent in microspore embryogenesis) and ‘269’ (low responsive parent) in Chinese cabbage,
and between ‘Lisandra’ (high responsive parent) and ‘Kamikita’ (low responsive parent) in oil seed rape. After 230 and 143
primers were screened, a total of 148 and 52markers were detected to be polymorphic between the parents in Chinese cabbage
and oilseed rape, respectively. Twenty-seven percent of the markers in the MD population showed a significant segregation
distortion in both crops. Of the markers showing segregation distortion in the MD population, 71–75% of the markers followed
the expected Mendelian segregation ratio in the F2 population. When the relationships between such distorted markers and microspore embryogenesis of the F2 population were examined, 7 and 3 markers were identified to be associated with embryogenic ability in Chinese cabbage and
oilseed rape, respectively. These markers showed additive effects on embryo yields, and the plants having more alleles of
the high responsive parent produced higher embryo yields. These markers maybe useful in marker-assisted selection for improving
microspore responsiveness straits in Brassica crops.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
Crossability and embryo rescue enhancement in wide crosses between wheat and three Agropyron species 总被引：2，自引：0，他引：2
Summary Soft winter wheat lines were crossed with Agropyron intermedium, A. elongatum and A. trichophorum using pollen from single plants of Agropyron spp. to pollinate wheat spikes. Not only species but also individual plants within varieties of Agropyron species differed in percent seed set with a wheat genotype. In two arrays of crosses between two phenotypically different plants of A. elongatum and nine wheat lines, one Agropyron plant gave higher seed set (overall=27.1%) than the other (overall=3.7%). The differences were significant in seven of the nine cross combinations. Results are consistent with the hypothesis that these two plants differ in their crossability as pollen parents with wheat, and suggest the possibility of occurrence of crossability genes in wheatgrasses. The success rate of hybrid embryo rescue was higher (87.5%) with cold treatment (4°C) than without cold treatment (75.0%) of excised embryos on culture media. Results underscore the significance of genotype of the alien species for crossing with low crossable wheats, and of the physical factors for improving embryo rescue in wide crosses.Contribution No. 11,825, Purdue Agric. Exp. Stn., West Lafayette, Indiana 47907, USA. The research was supported in part by Public Varieties of Indiana. 相似文献
14.
J. M. Andeweg 《Euphytica》1956,5(2):185-195
Summary Scab caused by the fungus Cladosporium cucumerinum, may cause serious damage to frame cucumbers. Bulbosan (trichlorotrinitrobenzene) is an effective chemical means of control. Between 1945 and 1954 this German fungicide could not be supplied, and, as a result, the need for resistant varieties became very great.Before 1920 scab-resistance in pickling cucumbers was already known to Dutch growers. Selection started around 1920 on the initiative of W. G. v. d. Kroft and resulted in scab-resistant pickling cucumbers of which Baarlose Nietplekker VI is still widely grown. In 1948 G. W. v. d. Helm (Exp. Garden at Sloten) started breeding a scab-resistant yellow slicing cucumber destined for gardeners in the neigh-bourhood of Amsterdam. The resistant variety Highmoor was used as one parent. In 1954 the yellow variety Vios and the white variety Mabro were introduced. In 1952 G. W. v. d. Helm at the Exp. Garden Sloten, and J. M. Andeweg at the Institute of Horticultural Plant Breeding, Wageningen, simultaneously started breeding green scab-resistant frame cucumbers, using Highmoor as the resistant parent. In 1955 the experimental garden at Sloten introduced the scab-resistant green slicing cucumbers Amato and Proso, while in 1956 the Institute of Horticultural Plant Breeding introduced the scab-resistant green slicing cucumber Esvier. In 1953 seed of 2 first-backcross populations was supplied by the Institute to seed growers. At present intensive breeding for scab-resistance is also being carried out by a number of Dutch seed growers.Scab-resistance depends on one dominant gene; and young plants can readily be tested for resistance. Consequently a backcross scheme can easily be carried out. Rapid breeding is possible because at least 2 cultures can be carried out yearly. If necessary, cuttings of promising plants can be taken. Before and after artificial pollination the flowers can be tied up with raffia. It is simpler, however, to pinch the flowers with a special stainless clip as originally used for grafting cucumbers.The uniform fruit colour of the Dutch green frame slicing cucumbers is a recessive character; the fruit length of the Dutch varieties is dominant. 相似文献
15.
Summary New types of diploids in Brassica crops were synthesized after three consecutive selfing of aneuploids derived from backcrossing of sesquidiploids (2n=29, AAC) with B. campestris (2n=20, AA). The cytogenetic and morphological characteristics of plants with 2n=22, 24 and 40 in the S3 generation were analyzed in order to establish the extent in which these addition and polyploid lines were stabilized. A high frequency of 11II (79.7%), 12II (84.6%) and 20II (100%), were observed at metaphase I of pollen mother cells in 2n=22, 24 and 40 plants, respectively. The chromosome configuration at methaphase II also indicates that a certain level of stability has been attained cytogenetically. Although pollen stainability was relatively high, the seed set percentage was still low. Variation in morphological characteristics indicate the incorporation of one or more chromosome pairs from the C genome of B. oleracea. Other diagnostic characters such as the formation of determinate inflorescence, branching from the base of the stem, and the shift from self-incompatibility to self-compatibility must have resulted from the interaction between A and C genomes. Thus plants with 2n=22, 24 and 40 have been stabilized to some extent and can be developed into new breeding lines of Brassica. It is suggested that limited pollination could be effective in increasing the seed fertility of these plants. 相似文献
16.
Black rot is a bacterial disease of Brassica oleracea caused by Xanthomonas campestris pv. campestris. Resistance to the major black rot races 1 or 4 has been identified in related Brassica species including B. carinata and B. napus. In this study, two B. juncea accessions (A 19182 and A 19183) that are resistant to races 1 and 4 of Xcc were used as maternal and paternal parents to generate interspecific hybrids with B. oleracea cultivars. Interspecific hybrids were recovered using the embryo rescue technique and confirmed through inheritance of paternal molecular markers. Twenty-six interspecific hybrid plants were obtained between A 19182 and B. oleracea cultivars, but no interspecific hybrids were obtained using A 19183. Although interspecific hybrid plants were male sterile, they were used successfully as maternal parents to generate backcross plants using embryo rescue. All hybrid and BC1 plants were resistant to black rot races 1 and 4. 相似文献
17.
Summary For haploid plant production in Idared apple, parthenogenesisin situ was induced by irradiated pollen. The most important restrictions were seed set, embryo germination and green plant recovery
from germinated embryos. The efficiency of green plant production was strongly influenced by irradiation dose, picking time
and quality of the irradiated pollen. 250 Gy pollen was more efficient for green plant production than 500 Gy pollen. Using
250 Gy pollen with reduced germination capacity resulted in a five-fold lower green plant yield. Delaying picking of the fruits
(140 instead of 70 days after pollination) had a significant positive effect. Up to 20 plants per 1000 pollinated flowers,
showing no expression of a marker gene present in the pollen parent, were obtained in some treatments.
Induction efficiency was high when seed weight was high. This offers the possibility of selecting seeds with the best chances
for haploid plant production. Heavy seeds generally contained visual normal developed embryos, which germinated better than
those from lighter seeds and gave normal plant development. Delayed picking increased the proportion of large seeds, suggesting
that pollination with irradiated pollen retards embryo development. From treatments with irradiated pollen of poor quality
more small seeds were harvested. 相似文献
18.
Parental effects on crossability,embryo differentiation and plantlet recovery in wheat x rye hybrids
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
19.
Summary Many conventional hard red spring wheat (Triticum aestivum L. em Thell) lines, including several North Dakota cultivars, carry a gene (or genes) which restore partial male fertility to male sterile plants with Triticum timopheevi
Zhuk. cytoplasm. Since this gene has no fertility restoration function in T. aestivum cytoplasm, the postulation can be made that it is being retained in conventional lines because of pleiotropic effects, favorable linkages or chance. The research reported in this paper examined these possibilities. Forty F6 lines, derived from a single F2 plant which was heterozygous for a gene (or genes) for partial fertility restoration, were evaluated for two years in a yield trial planted at Fargo, North Dakota. The 40 lines were testcrossed to a male sterile line having T. timopheevi cytoplasm, and the mean seed set of testcrosses was used as a measure of a line's fertility restoration potential. Twenty-seven lines had the gene for partial fertility, and 13 lines apparently lacked this gene. The 40 lines differed for heading date, anther extrusion, plant height, grain yield, 200-kernel weight, test weight, and grain protein percentage. However, comparisons of lines having the restorer gene with those lacking the gene did not provide any obvious explanation for the retention of the partial fertility restorer gene in the breeding stocks of the North Dakota conventional hard red spring wheat breeding program. The possibility that the restorer gene was linked with genes for resistance to stem rust or leaf rust also was evaluated by testing lines for their reaction to several races of rust. No conclusive association was found.Contribution from the Agric. Exp. Sta., North Dakota State University, Fargo, ND 58105, Journal Article no. 相似文献
20.
Summary The merits of mentor pollen in certain interspecific hybridizations in the genus Cucumis L. were evaluated. African wild cucumber species Cucumis metuliferus
Naud. and C. africanus L. and Asian species C. sativus var. hardwickii
Alef and var. sikkimensis
Hook, were reciprocally crossed. Pollen tube growth was arrested halfway down the style in all combinations except in C. sativus × C. africanus. Mentor pollen irradiated with 100 and 200 krad grew through the style and into the ovules in all species. Fruitset was obtained in all cases when mentor pollen was used either alone or in mixtures. Fruits set after self pollination with mentor pollen yielded only seeds without embryos.In several crosses, aided by mentor pollen, a number of relatively large seeds (with enlarged embryosac) were obtained. A sample of these embryosacs contained a globular structure like an embryo. Embryosacs with embryo-like structures were explanted on several different media but no development was obtained. 相似文献