共查询到20条相似文献，搜索用时 312 毫秒
1.
Summary The triploids recovered from 4x×2x crosses in three Solanum species were very vigorous and although few seeds/fruit were obtained when the triploids were crossed to diploids, the extensive crossing programme produced sufficient seed of four species cph, chc, pnt and tar. The average seed set for the 3x-2x crosses was an extremely low 3.5 seeds/fruit.Approximately 90% of the progeny of the 3x–2x crosses were aneuploids with chromosome numbers of 2n=25–29. The frequency of the aneuploids in the three species that were studied was chc 93%, pnt 94% and tar 92%. The aneuploids of chc and tar were extremely vigorous and fertile and they were used as females in crosses to the marker stocks. The aneuploids of pnt were vigorous, but the crossability barrier of pnt prevented their use in crosses to the marker stocks. A number of the aneuploids produced seed upon being selfed, but the ability to produce self seed may be related to the pseudo-compatibility of the parental clones. In only 7 aneuploids was there an indication that the self fertility was due to overcoming the self-incompatibility barrier as a result of competition-interaction of the aneuploid gamete.Plants in the families from the triploid-diploid crosses had a tremendous amount of variation in morphological characteristics (leaf shape, size and color; berry shape, color and degree or verrucose spotting: and plant habit and vigor). A large portion of variation exhibited in these families was due to the normal genetic segregation of the heterozygous parents. It was impossible to distinguish the aneuploids from their diploid sibs especially those having only one or two additional chromosomes because they were as vigorous and fertile as the diploids.There were some preliminary indications of the existence of distinct morphological characteristics among the aneuploids (separate petals, long berries, and extreme verrucose berries). However, there was no indication that these traits were due to the dosage effect of the extra chromosome. If it should be determined that this was true, it would be extremely useful in associating genes with chromosomes and determining the phenotypic effects due to the presence of an additional chromosome.Cooperative investigations of the College of Agriculture and Life Sciences, University of Winconsin and the Agricultural Research Service, U.S. Department of Agriculture, Madison, Wisconsin. Supported in part by grants from the Research Committee of the Graduate School, University of Wisconsin.First and third author respectively, formally Graduate Research Assistant Department of Horticulture, University of Wisconsin, Madison, and Geneticist Agriculture Research Service, U.S. Department of Agriculture, University of Wisconsin, Madison. Present address: Department of Genetics. University of Wisconsin, Madison, Wisconsin 53706 and Head Breeding and Genetics Department, International Potato Center, Lima, Peru. 相似文献
2.
Summary The breeding behaviour of aneuploids of guava (Psidium guajava L.) such as trisomic, tetrasomic, and higher aneuploids has been studied. Reciprocal crosses between aneuploids and diploids indicated less than 100% crossability. The aneuploids when used as male parents crossed less frequently than as female parents and certain aneuploids crossed more readily than others. Differences were observed in fruit size, fruit weight, and seed number in the reciprocal crosses.The extra chromosome was found to be transmitted through both the egg cell and the pollen. However, the frequency of transmission was greater through the egg cell than the pollen. As high as 26% transmission of extra chromosomes were obtained through the egg cell. There was no clear cut difference between trisomics and higher aneuploids with regard to the frequency of transmission of extra chromosomes. 相似文献
3.
Maternal and embryonal control of seed colour by different Brassica alboglabra chromosomes 总被引：2，自引：0，他引：2
Most oilseed rape, Brassica napus, cultivars are black‐seeded. The progenitor species, Brassica rapa, has either yellow or black seeds, while known cultivars of the other progenitor species Brassica oleracea/alboglabra have black seeds. To determine which chromosomes of B. alboglabra are carriers of seed colour genes, B. rapaalboglabra monosomic addition lines were produced from a B. napus resynthesized from yellow‐seeded B. rapa and brown/black‐seeded B. alboglabra. Eight out of nine possible lines have been developed and transmission frequencies of the alien chromosomes were estimated. Three B. alboglabra chromosomes in three of these lines influenced seed colour. B. rapa plants carrying alien chromosome 1 exhibited a maternal control of seed colour and produced only brown seeds, which gave rise to plants with either yellow or brown seeds. However, B. rapa plants carrying alien chromosome 4 or another as yet unidentified alien chromosome exhibited an embryonal control of seed colour and produced a mixture of yellow and brown seeds. The yellow seeds gave rise to yellow‐seeded plants, while the brown seeds gave rise to plants that yielded a mixture of yellow and brown seeds, depending on the absence or presence, respectively, of the B. alboglabra chromosome. Consequently, both maternal and embryonal control of seed colour are expected to contribute to the black‐seeded phenotype of oilseed rape. 相似文献
4.
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
5.
Veli-Matti Rokka Yong-Sheng Xu Jyri Kankila Anja Kuusela Seppo Pulli Eija Pehu 《Euphytica》1994,80(3):207-217
Summary Symmetric somatic hybrids were produced by electrofusion of protoplasts of two dihaploid tuber-bearing potato (Solanum tuberosum L.) lines and Solanum brevidens Phil., a diploid non-tuber-bearing wild potato species. A total of 985 plants was obtained. Verification of nuclear hybridity of putative hybrids was based on additive RAPD patterns, general morphological characteristics and chromosome counts. 53 (90%) calli regenerated into plants which were identified as somatic hybrids. Most of the hybrids were aneuploids at the tetraploid (4×) or hexaploid (6×) level. The 20 hybrids tested expressed a high level of resistance to potato virus Y (PVY
N
) characteristic of the S. brevidens parent. Resistance to late blight (Phytophthora infestans (Mont.) de Bary) varied between hybrids, but was on average better than that of the fusion parents. Resistance of hybrids to bacterial stem rot (Erwinia carotovora subsp. atroseptica (van Hall) Dye) was not superior to that of commercial potato cultivars. 相似文献
6.
A complete set of nine primary trisomics (2n+ 1) for cv.‘Yugu No. 1’of foxtail millet, Setaria italica (L.) Beauv. (2n= 2x= 18), was identified cytologically from progenies derived from crosses between autotriploids(2n= 2x= 27) and their diploid counterparts. Five autotriploid plants were identified from 2100 seedlings derived from 4x-2x crosses; the reciprocal crosses (2x-4x) failed to produce autotriploids. Autotriploids grew vigorously and were morphologically very similar to diploids. Theprimary trisomics (2n= 2x= 19) constituted ?32.5% of the total progeny from the 3x-2x crosses, whereas 59.8% of the descendants were aneuploids with chromosome numbers ranging from 20 (double trisomics and tetrasomics) to 37 (2n= 4x+ 1; or autotetraploid with one additional chromosome). The nine primary trisomics identified were self-fertile; seven had characteristic morphology, whereas trisomics VIII and IX resembled the disomics. The seed set for trisomic V was the lowest (20%), and trisomic VIII the highest (74%). Other aneuploids with 20 or more somatic chromosomes were either self-sterile or partially fertile with various, but low, levels of seed set. Each of the primary trisomics showed its unique transmission rate when self-pollinated; trisomic IX had the highest (45.8%), whereas trisomic V had the lowest (19.6%) transmission rate. 相似文献
7.
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
8.
Karyotype analysis and interspecific hybridisation in three perennial Sesbania species (Leguminosae)
Summary The somatic chromosome number in Sesbania sesban var. nubica, S. goetzei and S. keniensis (Leguminosae; Papilionoidae) was found to be 2n=12. These findings were in agreement with earlier reports on S. sesban and S. keniensis. The chromosome number 2n=12 is a new record for S. goetzei. Similarities in karyotypes were found in the three species. All species had one pair of long metacentric chromosomes; the second pair was submedian, followed by four smaller pairs of metacentric chromosomes. Nucleolar organiser regions in the form of satellites were found on the short arm of the fourth chromosome pair in S. sesban and S. keniensis. Interspecific crosses in all possible combinations were carried out, resulting in pod and viable seed formation for the crosses S. sesban x S. goetzei, S. sesban x S. keniensis, S. goetzei x S. sesban and S. goetzei x S. keniensis. The two crosses with S. keniensis as a female parent were unsuccessful. The hybrid plants established normally and produced viable seeds. 相似文献
9.
G. F. Marais 《Plant Breeding》1988,100(2):157-159
Pollination of ‘Chinese Spring,’ monosome 1D plants with rye results in failure of hybrid seed development in a proportion of the F1 seeds corresponding to the transmission rate of the nullisomic 1D egg cells. Development and viability of these hybrid seeds closely resemble that normally observed in T. aurum× rye crosses. Using ‘Chinese Spring’ chromosome ID telosomic plants in crosses with rye, it was possible to illustrate that the observed effect was associated with the long arm of this chromosome. 相似文献
10.
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
11.
Summary Aneuploids with 2n=21 and 2n=22 derived from crossing of sesquidiploids (2n=29, AAC) and Brassica campestris (2n=20, AA) were selfed successively in order to follow the changes in chromosome number of the progenies for three consecutive generations. Progenies with 2n=22, 23 and 24 obtained after selfing of S0 generation and the succeeding S1, S2 and S3 generations were analyzed in terms of pollen stainability, % seed set as well as cytogenetically based on meiotic behaviour with the aim of determining the possibility of addition of one or more alien chromosomes into n=10 species which may lead to differentiation of single or plural disomic addition lines. The generation of aneuploids with 2n=21 progressed in such a way that most plants seem to revert to the 2n=20 chromosome number of B. campestris after selfing. From 2n=22 aneuploids, however, the succeeding progenies showed high frequency of plants with two additional chromosomes which accounted for 50.6% and 52.9% of total S3 progenies via 2n=22 and 2n=24 S2 generations, respectively. The meiotic behaviour of these progenies indicated evidence for a rule governing the frequency distribution of chromosome number among these addition lines and high possibility to breed such disomic plants with 2n=22. A method of selecting stable aneuploids was suggested in addition to the possible role of pollination biology at various processes of such breeding program. 相似文献
12.
J. G. Th. Hermsen 《Euphytica》1969,18(2):183-189
Summary The species Solanum chacoense BITT. (2n=2x=24) is a tuber-bearing, self-incompatible species which is important both for breeding and for genetic research. It crosses readily with most other tuber-bearing Solanum species including the common potato S. tuberosum (2n=4x=48). Gametophytic incompatibility hampers research in and utilization of this species. Doubling the chromosome number by colchicine makes it a self-compatible autotetraploid. By crossing selfed progeny of 4x-S. chacoense with a number of haploid-inducing diploid Solanum species a high yield of different dihaploid S. chacoense individuals (2n=24) could be obtained from one originally diploid clone: S. chacoense CPC 1153. More than 160 haploids showing a large variability were identified. The average haploid frequency was 53.7 per 100 berries. Most hybrid plants (70–100%) from four 4x × 2x crosses studied were tetraploid. The frequency of triploid hybrids was low (0–10%). Haploid-inducing capacity of fifteen male parents used in this study varied from 0–141 haploids per 100 berries. Careful examination of 156 haploids revealed 15 viable aneuhaploids (2n=25, 26, and 27), i.e. 9.4%. The potential value of these aneuhaploids is discussed.About 50% of the haploids were sufficiently male fertile to use them in crossing. A few of them set berries after selfing. Five aneuhaploids including the one with 27 chromosomes were successfully crossed as females with a diploid hybrid clone. 相似文献
13.
S. Cooper-Bland M. J. De Maine H. E. Stewart M. L. M. H. Fleming M. S. Phillips A. Kumar 《Euphytica》1996,90(2):209-216
Intraspecific tetraploid somatic and sexual hybrid plants have been resynthesised following protoplast fusion and by sexual crosses between two dihaploid potato (Solanum tuberosum) lines each possessing complementary agronomic traits. The dihaploid PDH 40 possesses good tuber shape and yield but has foliage susceptibility to late blight (Phytophthora infestans). On the other hand, the dihaploid PDH 727 possesses resistance to blight in the foliage but has a low yield of small and irregular shaped tubers. Since it was only possible to use a partial selection strategy based on culture media to facilitate recovery of somatic hybrid plants-further morphological and esterase isozyme based characterisations were performed to identify somatic hybrid plants from amongst the non-hybrid plant material. When the blight resistance of both the intraspecific somatic and sexual hybrid plants was assessed there was no significant difference in the mean resistance value and it was intermediate between those of their parents. However, the range of resistance was much wider among the sexual hybrids than among the plants derived from somatic fusion. An assessment of tuber yield between tetraploid sexual and somatic hybrids showed no significant difference and it was higher than that of either parent value. The implication of these results in the context of potato genetics and breeding is discussed. 相似文献
14.
To transfer the genes for yellow seed coat from both genomes A and C to B. napus (AACC), the hexaploid of Brassica (AABBCC)
was synthesised from reciprocal interspecific crosses between yellow-seeded B.campestris (AA) and B.carinata (BBCC). The hexaploid
with 27 pairs of chromosomes was red-seeded which showed that genic interaction existed in the trigenomic plants for the colour
of the seed coat. Hundreds of hybrid seeds were obtained from crosses between the red-seeded hexaploid and partial yellow
or brown-seeded varieties of B. napus as pollen donor. The majority of the hybrid plants (AABCC) were self fertile with brown
seeds. It appeared that the chromosomes of the B genome were excluded during the meiosis of the pentaploid and a high proportion
of the genetically balanced AC gametes could be produced. The fertility of the F2 population was increased and even reached
normal levels for some plants. Seventy-three plants with the yellow-seeded character were isolated from 2590 open-pollinated
F2 plants, most with increased fertility. After two successive self-pollinations, 18 lines produced yellow seeds and no brown
seeds segregated from these populations. The morphology of the novel yellow-seeded plants was basically towards B. napus.
Esterase isoenzyme electrophoresis showed that the plants contained some of the genetic background of B. campestris, B. carinata
and B. napus. Cytological analysis has shown that at least some yellow-seeded lines have the B.napus AACC genome composition
with 38 chromosomes and normal meiotic pairing.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
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
16.
Summary Monohaploid Solanum tuberosum plants were produced from the anthers of a dihaploid genotype. From another dihaploid genotype plants containing 36 chromosomes were obtained. For plantlet production anthers containing pollen at the uninucleate microspore stage were inoculated on a Linsmaier and Skoog-based medium supplemented with 1 mg/1 indole-3-acetic acid and 1 mg/1 benzyl aminopurine.Anthers from donor plants grown either in the summer or in the winter responded similarly on a range of media. Anther response in the form of callus induction and root formation was at least partly dependent on the genotype of the donor dihaploid plant. 相似文献
17.
Summary A number of crosses were made between diploid and tetraploid Lolium perenne plants in order to determine the degree of cross compatibility between the two different ploidy levels. The range of hybridization undertaken involved diploidxdiploid, and tetraploid x tetraploid control crossings, diploid x tetraploid crosses, tetraploid x diploid crosses and mixed pollinations. The seed set, the germination capacity of resultant hybrid seeds, and the chromosome constitution of derived seedlings was determined. In addition attempts were made to culture 12 day-old hybrid embryos from the diploid x tetraploid and reciprocal crosses.The crossing results obtained indicated no barrier to fertilization between diploids and tetraploids, but the irregular and poor development of the seed accompanied by much reduced germination, indicated unsatisfactory endosperm establishment of large numbers of triploids, as confirmed by the result of culturing embryos dissected from 12-day old seeds.In preliminary studies undertaken to determine the extent to which diploid and tetraploid ryegrass varieties intercross when grown in close proximity for seed production, Griffiths and Pegler (1966) observed a very low incidence of triploids amongst the progenies of diploid plants exposed to the pollen of tetraploid plants and also amongst the progenies of tetraploid material exposed to the pollen of diploid plants.In these and subsequent studies it was noted that only a very small proportion of the so-called fully formed seeds derived from diploid x tetraploid crosses did actually germinate. When, in 1964, propagules of clones of S.24 perennial ryegrass, well separated from one another, were placed in drills of the tetraploid perennial ryegrass variety Reveille, the proportion of florets which formed caryopses, and of caryopses which germinated was as follows (Table 1).The data (Table 1) clearly indicate that a considerable proportion of the S.24 florets had been fertilized by 2n pollen and had formed caryopses, but most of these had proved to be defective. As noted in the previous studies, the frequency of triploid seedlings was low, thus suggesting incompatibility between the n and 2n gametes for the production of viable zygotes.Of the total progenies classed as tetraploids in the early seedling stage, 80% proved to be ryegrass x tall fescue F1 hybrids. These arose as a result of free crossing with 相似文献
18.
To further utilize the valuable germplasm Orychophragmus violaceus for Brassica genetics and breeding, a B. napus × O. violaceus cross was repeated with embryo rescue. All F1 plants except one B. napus haploid were mixoploids (2n = 17–39 in ovaries) with 2n = 31, 37, 38 and 39 as the maximal chromosome numbers in individuals, but the higher numbers mostly appeared in pollen mother cells (PMCs) with a preponderance of 2n = 30, 37 and 38. Only one chromosome and one chromosome segment of O. violaceus were detected at a low frequency in some ovary cells and PMCs with 2n = 37, 38 and 39 as determined by genomic in situ hybridization analysis. The fatty acid profiles of seeds from the majority of the F1 and F2 plants were similar to those of female B. napus cv. ‘Oro’, but some were obviously different in the percentages of oleic, linoleic and erucic acids, and some F2 plants (2n = 38) with good seed set had high percentages of oleic (>70.0%) or linoleic (to 38.3%) acids and low erucic acid (<1%). Subsequently, many kinds of B. napus aneuploids (2n = 28, 30, 34, 36, 37, 39 and 42), without O. violaceus chromosomes, were derived from F2 progeny and microspores of partial F1 plants. Finally, the cytological mechanisms behind the variations in chromosome numbers were discussed together with the implications of these aneuploids for Brassica genome research and of the plants with altered fatty acid profiles for improving the oil quality of B. napus. 相似文献
19.
通过对籼粳交Ｆ１体细胞愈伤组织的秋水仙素处理和四倍体花药培养，建成了水稻四倍体诱导及双单倍体分解系统。应用这一系统获得了４４个籼粳交组合的双单倍体及其自交４后代。对这些双单倍体及其后代的遗传分析表明，籼粳交育性可能受寡基因控制，双单倍体途径通过改变正常的世代交替过程，能部分克服籼粳交的不育性及倾籼或倾粳的偏态分离，并具有比Ｆ２更丰富的遗传多样性。在双单倍体一代群体中，育性正常的植株约占４０％，这是 相似文献
20.
Breeding for quantitative resistance to potato cyst nematode (Globodera pallida) in tetraploid potatoes using dihaploids and unreduced gametes 总被引：1，自引：0，他引：1
Summary Dihaploids were produced from tetraploids resistant to potato cyst nematode (Globodera pallida (Stone)). High levels of resistance were found in the dihaploids and three were used to produce tetraploid progenies by crossing them with susceptible tetraploid cultivars. One dihaploid, PDH505, produced more highly resistant offspring than the other two, PDHs 417 and 418. The latter gave progenies whose levels of resistance were similar to those obtained from susceptible dihaploids crossed with resistant tetraploids.The differences between the progenies of the resistant dihaploids were probably due to different modes of unreduced gamete formation (PDH505 producing gametes by first division restitution (FDR) and PDHs 417 and 418 by second division restitution (SDR)) although cytological studies would be necessary to confirm this. The methods by which dihaploids could be utilised in a tetraploid potato breeding programme are discussed in relation to the mode of unreduced gamete formation. 相似文献