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1.
Summary The expression of leaf isozymes and tuber patatin in dihaploids derived from the Solanum tuberosum cv. Pentland Crown was investigated. Seven of the dihaploids were aneusomatic containing additional chromosomes from the S. phureja dihaploid inducer. Of these, four genotypes expressed leaf isozymes characteristic of the S. phureja dihaploid inducer, and the tubers of three aneusomatic dihaploids contained a S. phureja form of patatin. Aneusomatic dihaploids in which the proportion of cells containing additional S. phureja chromosomes was relatively small (i.e. 1–15%) did not express leaf isozyme markers or patatin bands characteristic of the dihaploid inducer or showed only faint expression of one or two markers. However, those with a high proportion of cells containing additional chromosomes (50–55%) had a range of strongly expressed leaf isozymes that were characteristic of the dihaploid inducer and also expressed the S. phureja tuber patatin.One dihaploid genotype was exclusively euploid (2n<24), yet is expressed a S. phureja leaf isozyme marker and S. phureja tuber patatin, suggesting recombination or chromosome substitution between the genome of the S. phureja dihaploid inducer and the cultivar Pentland Crown. 相似文献
2.
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
3.
R. C. B. Hutten E. J. M. M. Scholberg D. J. Huigen J. G. Th. Hermsen E. Jacobsen 《Euphytica》1993,72(1-2):61-64
Summary The production of dihaploids is the first step in a potato breeding program at the diploid level. Dihaploid induction ability, dihaploid production ability and seed parent x pollinator interaction were analyzed for 28 × 3, seed parent x pollinator combinations. This is the first report on significant interaction between seed parents and pollinators. Despite this interaction, IVP 101 had a significantly higher dihaploid induction ability than the widely used pollinators IVP 35 and IVP 48. Previous findings on significant differences in dihaploid production ability between seed parents were clearly confirmed. 相似文献
4.
Summary Three dihaploids, two tetraploid cultivars and an unnamed tetraploid potato were subjected to three fertiliser treatments in a glasshouse. One dihaploid (PDH135), as well as being high yielding, responded to fertiliser dosage in a similar way to the cultivars by increasing tuber yield with each increase in fertiliser. The other two dihaploids increased shoot growth rather than tuber yield.An evaluation of tetraploid offspring obtained from dihaploid × tetraploid crosses, showed that PDH135 had the highest-yielding progenies in field trials. Other characters of the dihaploids were efficiently transferred into their tetraploid offspring. The use of dihaploids and unreduced gametes in breeding cultivars with useful quantitative characters is discussed. 相似文献
5.
Dihaploids were assumed to be of parthenogenic origin but cv. ‘Pentland Crown’ dihaploids produced at the Scottish Crop Research Institute (SCRI), Dundee, Scotland, are known to contain DNA from the S. phureja dihaploid inducer. This study investigates whether inducer DNA occurs in dihaploids of cultivars ‘Aminca’, ‘Brio’, ‘Lizen’ and ‘Sirtema’, produced at INRA, Ploudaniel, France. Two microsatellite markers and five simple sequence repeat 5′-anchored polymerase chain reaction (PCR) primers were used to generate markers. Markers originating from the dihaploid inducer were detected in 13 of the 19 INRA dihaploids and in some dihaploids from each cultivar. Greater introgression occurred in ‘Lizen’ dihaploids than in ‘Brio’ dihaploids, suggesting that the female (S. tuberosum) parent influences introgression. The percentage of INRA dihaploids containing inducer DNA was similar to that for ‘Pentland Crown’ dihaploids (c. 65%). The micro-satellite markers provided the first evidence of the transfer of specific, potentially useful, genes from the inducer to the dihaploid offspring. Interspecific introgression during dihaploid induction is more widespread than previously thought and researchers should be aware that it may influence the results of research using dihaploids. 相似文献
6.
Summary Dihaploid and dihaploid derived clones of Solanum tuberosum and diploid genotypes of S. verrucosum produced 85 viable monohaploids by female parthenogenesis. All were induced using diploid S. phureja clones, homozygous for embryo spot, as pollinator. Frequency of S. tuberosum monohaploids per 100 berries was rather constant in three successive years (14, 17 and 17 respectively). No male and female fertility was found in flowering monohaploids.Colchicine-induced chromosome doubling yielded homozygous s. tuberosum diploids with low pollen quality but good seed fertility.Two diploid self-incompatible species (S. multidissectum and S. berthaultii) produced no monohaploids. The presence of genes for female parthenogenesis in some dihaploids is discussed. 相似文献
7.
Wei Song Hao Xie Qing Liu Chaojie Xie Zhongfu Ni Tsomin Yang Qixin Sun Zhiyong Liu 《Euphytica》2007,156(1-2):95-102
The traditional process of obtaining maize hybrids involves the generation of inbred lines through successive generations
of selfing and subsequent testcrosses in order to identify the best combining ability by allelic complementation. A fast alternative
to obtain inbred lines is to induce the formation of haploids followed by chromosome doubling. However, even with the aid
of haploid-inducing genetic sources, this strategy has not been widely used in maize breeding programs, partly due to difficulties
inherent to haploid generation and identification. In order to evaluate the possibility of using dihaploids to generate homozygous
maize tropical lines, we used the androgenetic haploid inducer line W23 as a female parent in crosses with the tropical single-cross
hybrid BRS1010. Within the progeny of these crosses, 462 seeds were phenotypically selected as putative haploids by the purple-colored
endosperm and colorless embryo conditioned by the R1-nj gene. Among these, only four individuals were confirmed as being haploids using SSR markers, chromosome counting and flow
cytometry, showing that the phenotypic marker was not efficient in detecting haploids in the tropical maize genotype used.
All four haploids as well as some diploid plants presented reduced size, corroborating the difficulties for haploid identification
by phenotypic evaluation. Genetic diversity analysis revealed by SSR markers divided the haploids in two groups represented
by flint and dent maize inbred lines, which could be helpful in identifying complementary dihaploid lines. The present article
demonstrates that a combination of haploid production and SSR fingerprinting is a feasible strategy for maize hybrid development
in tropical germplasm. 相似文献
8.
Polyploidy in blackberries and ploidy differences between Rubus species are obstacles to the efficient introduction of valuable germplasm, both intra- and interspecific, into blackberry breeding programs. Expansion of the germplasm base would be facilitated by reducing the ploidy level of blackberry cultivars to the diploid level. In this report selection of twin seed, interspecific hybridization, and pollen irradiation were compared as methods in the recovery of dihaploids from tetraploid blackberry cultivars. One dihaploid was obtained through selection of twin seed and several were obtained following interspecific hybridization. The infrequency of twinning and difficulty in detecting twin seed in Rubus reduced the efficiency of this method. The efficiency with which dihaploids could be obtained following interspecific hybridization varied with the pollen parent. Reduced seed set and seed quality following pollinations with respectively R. parvifolius and R. hirsutus could be used to advantage in the recovery of dihaploids from blackberries. Ploidy reduction in several tetraploid blackberry cultivars was obtained following pollinations with 100 and 150 kR gamma irradiated pollen. Most of the seedlings obtained at the 50 kR dosage were aneuploid. Pollen irradiation at 150 kR was the most efficient method of obtaining dihaploids from tetraploid blackberries. Twenty percent of the seedlings obtained following this treatment were dihaploid. 相似文献
9.
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
10.
Dihaploid derivatives of 4x Rosa hybrida L. obtained through parthenogenesis induced by irradiated pollen significantly produce 2n eggs,often accompanied by gametes with higher ploidy levels (3x and 4x). The gamete ploidy level distribution depends on the originating genotype. The ploidy level of the male parent affects the maternal /paternal ratio in the endosperm, which can be involved in the counter-selection of triploid genotypes resulting from the crosses made between dihaploid and 4x Rosa hybrida.The observed segregation ratios of flower doubleness in triploid progenies of dihaploids × R. wichuraïanasuggest that the relevant locus could be positioned far from the centromere. 相似文献
11.
Summary Initial single and double trisomics of S. tuberosum Group Tuberosum cv. Gineke were successfully crossed with and backcrossed to clones obtained through inbreeding of self-compatible dihaploids of the same variety. Some trisomics showed reduced flowering or flower abnormalities and contributed therefore only to a small extent. Berry-set and seed-set varied considerably. There was no relation between these phenomena, nor was there any relation between either berry-or seed-set and the identity of the extra chromosome in the female parent. Seed-set seemed to be influenced by the male parent. When a more inbred male parent was used in the crosses with trisomics this often resulted in less seed per cross. There was no clear relation between seed-set and stainability of the pollen grains, but both the strong selection for good pollen and the high level of self-compatibility, have apparently contributed to the success of the crosses. The double trisomic plants yielded less seed than most single trisomics. Only three of the single trisomics produced stainable pollen and two of them yielded progeny when used as male parent in crosses or selfings.In the progenies several of the trisomic types could be distinguished on the basis of plant morphology in the young seedling stage. For ten different trisomics the morphotype is being described. The average rate of female transmission of the extra chromosome was about twenty per cent, but there was a wide variation, both between and within the various trisomic types. The results indicated that for chromosomes 3 and 8 the rate of transmission was higher than the average value. In one out of two trisomic types male transmission of the extra chromosome occurred, with a rate of 4.7%. The possible causes for the observed differences in female transmission of the extra chromosome are being discussed. 相似文献
12.
M. J. De Maine 《Euphytica》1978,27(1):305-315
Summary An examination of the feasibility of obtaining dihaploids with high levels of field resistance to important potato pathogens, showed that dihaploids may be produced which are more resistant to late blight or to potato root eelworm pathotype E than are their tetraploid parents. The significance of this is discussed in relation to the possible types of gene action involved in conferring field resistance. 相似文献
13.
油菜小孢子培养影响因素及黄籽油菜双单倍体群体的构建 总被引：5，自引：0，他引：5
针对我国油菜小孢子培养供体材料一般种植在大田,受外界环境影响较大,出胚率较低的现状,对大田环境条件下小孢子培养的主要影响因素进行了研究。同时,为了构建黄籽油菜双单倍体群体,研究了黄籽油菜的出胚情况。结果表明,不同取样时间对小孢子胚状体再生频率的影响很大;秋水仙素处理游离小孢子对胚状体的诱导有一定的负面影响,浓度越高,影响越大;黄籽油菜的出胚率较低(0.56枚/皿),同样条件下,不到黑籽油菜的1/8。不同黄籽单株间出胚率差异较大,变异幅度在0.04~1.97枚/皿。采用小孢子苗直接移栽大田技术,移栽成活率达89.0%,经染色体加倍后,最终构建了含有127个株系的黄籽油菜双单倍体群体。 相似文献
14.
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
15.
An investigation was made on the origin and basis of somaclonal variation in potato. Plants were regenerated from protoplasts of dihaploid and tetraploid potato, and the degree of variation in phenotype and chromosome number was analysed. All the regenerants from dihaploid potato showed variation in chromosome number, while only part of these varied in plant morphology. In tetraploid potato, 60 % of the regenerants showed variation in chromosome number, all of which exhibited phenotypic changes. The data suggest that the explant source and the initial ploidy level of the genotype play an important role in influencing the degree of somaclonal variation. 相似文献
16.
Summary Anthers of the diploid (2n=77) and the colchi-tetraploid (2n=154) Pelargonium roseum were cultured in vitro. In both ploidy level anthers containing uninucleate or binucleate microspores were incubated on a modified White's medium. Calli formed were then subcultured on Murashige and Skoog's medium for organoid differentiation. Plants developed from organoids were transferred to filter paper bridges and after that transplanted into pots. Plants derived from anthers of the tetraploid had diploid chromosome number. Wide variation of their essential oil components suggested their genetic heterogeneity. Further, high correlations between different seasons in the rate of essential oil components showed that the wide variation was due to genetic differences. Therefore, these plants probably originated from pollen grains. On the other hand, plants derived from anthers of the diploid had diploid chromosome number. Small variation and low correlations between different seasons in essential oil components indicated their genetic homogeneity. Their origin was ascribable to the somatic tissues of the mother plant. It is concluded that in plant species in which usual sexual reproduction is difficult, anther culture of chromosome-doubled plants will give a useful method for obtaining genetic variation. 相似文献
17.
J. G. Th. Hermsen 《Euphytica》1978,27(2):381-384
Summary Three dihaploids of Solanum tuberosum (two self-compatible, one self-incompatible) were found to be heterozygous for a monogenic recessive virescent mutant. Intercrossing resulted in the expected 3 : 1 ratio only in crosses involving one self-compatible and one self-incompatible parent. Self-compatible x self-compatible matings produced F1's in which 6:1 was found. The same ratio was observed in the self progeny of the two self-compatible dihaploids. This significant deviation could be explained by assuming linkage (25% crossing-over) between v and an S-bearing translocation. This translocation causes self-compatibility in the dihaploids used and early lethality when homozygous. 相似文献
18.
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
19.
The occurrence of 2n-pollen and the origin of sexual polyploids in dihaploid roses (Rosa hybrida L.)
Haploidisation by in situ parthenogenesis of 4x R. hybrida resulted in the production of some dihaploid roses (2n=2x=14) able to produce viable pollen. A cytological study of microsporogenesis
revealed that, although the first meiotic reductional division occurred normally, the second (equational) division was characterised
by frequent abnormalities which concerned spindle formation and led to unreduced gametes of First Division Restitution (FDR)
type. Analysis of the hybrid progeny of a parthenogenetically derived male fertile dihaploid plant revealed a selective advantage
of the 2n-pollen, especially in the case of an hybridization with a tetraploid female parent. Moreover, crosses carried out
among dihaploid partners always resulted in hybrids with ploidy levels≥ 3x.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
Summary An interspecific hybridization program designed to transfer gene(s) controlling apomixis from Pennisetum squamulatum Fresen. (2n=6x=54) to induced tetraploid (2n=4x=28) cultivated pearl millet, Pennisetum americanum (L.) Leeke resulted in four offtype plants, two with 27 chromosomes and two with 28 chromosomes. These plants were found among 217 spaced plants established from open-pollinated seed of an apomictic 21-chromosome polyhaploid (2n=21) plant derived from an apomictic interspecific hybrid (2n=41) between tetraploid pearl millet and Pennisetum squamulatum. It appeared that a 21- (or 20-) chromosome unreduced egg from the apomictic polyhaploid united with a 7-chromosome pearl millet (2n=2x=14) gamete to produce a 28- (or 27-) chromosome offspring. Meiotic chromosome behavior was irregular averaging from 3.60 to 4.05 bivalents per microsporocyte in the 27- and 28-chromosome hybrids. The 27- or 28-chromosome hybrids, like the 21-chromosome female parent, shed no pollen, but set from 1.8 to 28 seed per panicle when allowed to outcross with pearl millet. Progeny of the 28-chromosome hybrids were uniform and identical to their respective female parents, indicating that apomixis had been effectively transferred through the egg. In addition, a 56-chromosome plant resulting from chromosome doubling of a 28-chromosome hybrid was identified. Pollen was 68 per cent stainable and the plant averaged 2.3 selfed seeds per panicle. Chromosomes of the 56-chromosome plant paired as bivalents (x=10.67) or associated in multivalents. Three to nine chromosomes remained unpaired at metaphase I. Multiple four-nucleate embryo sacs indicated the 56-chromosome hybrid was an obligate apomict. The production of 27-, 28-, and 56-chromosome hybrid derivatives were the results of interspecific hybridization, haploidization, fertilization of unreduced apomictic eggs, and spontaneous chromosome doubling. These mechanisms resulted in new unique genome combinations between x=7 and x=9 Pennisetum species. 相似文献