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1.
Pollination with gamma-irradiated pollen and development of fruits,seeds and parthenogenetic plants in apple 总被引：3，自引：0，他引：3
Summary Four apple (Malus X domestica) genotypes, Erovan, Golden Delicious, R1-49 and X6677, were pollinated with a marked pollen irradiated by -rays at doses ranging from 125 to 1000 Gy. Pollination with such irradiated pollen affected fruit set, seed number and seed contents, and induced the formation of parthenocarpic fruits and the development of parthenogenetic embryos. The immature embryos extracted from seeds. 2 and 3 months after pollination, were cultured in vitro and germinated after 2 months of cold treatment (3°C). Haploid plants were obtained in all 4 genotypes, after pollination with pollen irradiated at doses from 200 to 500 Gy. The optimum conditions for induction of apple haploids, by irradiated pollen approach, have been established. 相似文献
2.
Pollen of garden varieties and species of Delphinium that was cryopreserved at –30 °C after 3 hours of air drying and storage on silica gel, had high germination and pollen tube growth in vitroeven after 180-day storage. On the other hand, pollen stored at 25 °C showed a marked decrease in the germination rate within 10 days. The best in vitro germination of Delphinium pollen was on a 1% water agar containing 15% sucrose and 0.005 to 0.01% boric acid and at 15 to 20 °C. Field pollination with the cryopreserved pollen showed higher fruit and seed set than pollination with pollen stored at
25 °C, and was not significantly different from fresh pollen.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
Summary Two self-incompatible Upper Amazon cacao clones, T85/799 and T79/501, were pollinated with compatible Amelonado pollen subjected to varying doses of gamma irradiation (10–100 Gy). The proportion of flat non-viable beans to fully formed, viable beans in the pods increased with an increase in dosage of gamma rays. At 60 Gy all the beans produced were flat and non-viable, beyond this dosage fruit set was zero. Pollinating the self-incompatible cacao clones with a 1 : 1 mixture of compatible mentor pollen irradiated at 60 Gy and normal self pollen produced a mixture of flat, non-viable beans and fully-formed viable beans. Similar experiments using irradiated pollen with a marker gene suggested that the fully-formed viable beans resulted from selfing. Increasing the proportion of the radiation-treated compatible pollen in the mixture increased the number of fully-formed beans. However, when compatible pollen which had been treated either at 80 Gy or with temperatures of 35° C, 40° C and 45° C for periods of five, ten and fifteen minutes in factorial combination were mixed with self pollen, no successful pollinations were achieved. Pollen viability tests indicated that, whilst pollen treated at 60 Gy were about 50% viable, those treated at either 80 Gy or with temperatures of 35–45° C were mostly not viable. This suggests that, to overcome the incompatibility in cacao, the tubes of the mentor pollen grains used should at least grow into the style. The possible causes for overcoming the self-incompatibility in cacao are discussed. 相似文献
4.
Summary A quantitative examination of pollen grain germination and pollen tube growth within the overy wall was made in selected wheat × tetraploid H. bulbosum hybridizations, to investigate the effect of the wheat and the H. bulbosum genotype on these characters. As expected, variation at the known crossability loci had no effect on pollen grain germination. The frequency of pollen tube penetration of the ovary wall was, however, severely reduced when the dominant alleles were present. Pollen tube penetration was nevertheless observed in 3 of the 110 ovaries examined of the non-crossable cultivar Highbury. The H. bulbosum genotype had a much smaller effect on these characters, but significant differences between the clones were observed in the numbers of pollen tubes initially penetrating the ovary wall. Although two H. bulbosum genotypes showed no significant differences in the number of ovaries with pollen tubes at the base of the ovule, significant differences in the frequency of fertilization were observed. The possible cause of this discrepancy is discussed.The frequency of fertilization in crossable wheat × H. bulbosum hybridizations was improved by the application of gibberellic acid within 10 minutes of pollination, and reduced by an increase in the ambient temperature from 20°C to 26°C. Fertilization following the pollination of non-crossable wheat genotypes was not affected by either of these factors. 相似文献
5.
Obtention of haploid embryos and plants through irradiated pollen technique in squash (Cucurbita pepo L.) 总被引：1，自引：0，他引：1
The influence of gamma ray doses (25, 50, 75, 100, 200, 300 and 400 Gy) and genotypes (Eskenderany F1, Acceste F1, Sakiz, Urfa Yerli) on the induction of haploid embryos obtained by irradiated pollen technique was studied in squash (Cucurbita pepo L.). Different shapes and stages of embryos were derived from seeds extracted from fruits harvested 4–5 weeks after pollination.
As a result of the present study, haploid embryos and haploid plants were obtained, with haploid production strongly influenced
by gamma ray doses, embryo stages and genotypes. Gamma ray doses of 25 and 50 Gy gave the highest parthenogenetical response.
All of the point shape, globular shape, arrow tips and stick-shaped embryos developed into haploid plants. However, only 53.8%
of torpedo and 23.1% of heart-shaped embryos gave haploid plants. In contrast, cotyledon-shaped and amorphous-shaped embryos
produced only diploid plantlets. The number of embryos per 100 seeds was the highest in ‘Eskenderany F1’ and ‘Sakiz’ genotypes. After in vitro culture, a total of 93 haploid plantlets were obtained.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
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
7.
Summary Selection among microgametophytes usually exploits variation in pollen grain germination. Studies of variation in pollen grain size in common bean (Phaseolus vulgaris L.) suggested that selection for size might lead to changes in sporophytic traits. To determine whether microgametophytic selection based on size would affect pollen grain size in subsequent generations or sporophytic traits that were correlated with pollen grain size, pollen grains from three crosses were separated into two size categories by sieving and then used to pollinate cv. Diacol Calima. Selection resulted in changes in pollen grain diameter for pollen from F1, F2 and F3 plants for all crosses. In vitro germination indicated no differences between vigor of large and small grains, but extraction and sieving reduced germinability. F1 seed from two of the crosses with size-selected pollen varied in weight according to pollen grain size, but in subsequent generations, the effect disappeared. Both size categories of selected pollen resulted in F2 progeny with reduced numbers of seeds per pod as compared to controls, suggesting that the size selection process may have resulted in indirect selection for traits reducing seed set. The overall results suggested that genes determining pollen grain size in bean have little or no effect on sporophytic traits such as seed size and seed yield. 相似文献
8.
We report, for the first time, there generation of four homozygous lines in sweet cherry (Prunus avium L.) byin situ parthenogenesis followed by embryo and cotyledon culture. The sweet cherry cultivar ‘Altenburger’ was pollinated with marked
pollen irradiated by γ-rays at doses ranging from 250 to1200 Gy. Pollination with such irradiated pollen affected fruit set
and the quality of the embryos, and induced the formation of parthenogenic embryos. The immature embryos extracted from the
stones, 35 or 75days after pollination, were cultivatedin vitro in an embryo or cotyledon culture. Although flow cytometrical analysis demonstrated the diploid level for all regenerants,
four lines could be characterized as homozygous using isoenzyme analysis.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Summary Fertilization and early seed development was studied in the variety Chinese Spring of common wheat (Triticum aestivum L.) after pollination with rye (Secale cereale L.) and selfing, and in the common wheat variety Hope after selfing. In all three combinations the first pollen tube reached the micropyle in about 40 min after pollination. When pollinated with rye the migration of the sperm nuclei to the egg cell and the polar nuclei was delayed by about an hour. In the subsequent development until 72 hours after pollination the average cellular and nuclear doubling times of embryo and endosperm were about 16 and 8 hours for the interspecific combination. 18 and 9 hours for Chinese Spring selfed and 20 and 12 hours for Hope selfed. 相似文献
10.
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
11.
Byron L. Burson 《Euphytica》1987,36(2):641-650
Summary Crossability between most Paspalum species is very low. This study was undertaken to identify the impediments to hybridization. Accessions of P. intermedium
Munro. ex Morong, P. jurgensii
Hackel and P. dilatatum
Poir were self-pollinated and crossed with one anther. Paspalum intermedium is essentially self-sterile but P. jurgensii and P. dilatatum are highly self-fertile. Following pollination, pollen germination and tube growth were studied by observing the pollinated pistils with fluorescent microscopy. Examination of self-pollinated pistils revealed that the pollen germinated shortly after contacting the stigmas. Germination was over 80% for the P. intermedium and P. dilatatum accessions but only 57% for P. jurgensii. Pollen tubes grew to the micropyle within 45 minutes after pollination in P. dilatatum and 1 hour and 15 minutes in P. jurgensii. However, in the P. intermedium accessions most tubes did not grow beyond the stigma and very few penetrated the style and ovary. Apparently stylar-incompatibility is the reason for the low selfed seed set. In the cross-pollinations, pollen germinated shortly after pollination and germination ranged from 57 to 88% for the different crosses. In all crosses the pollen tubes grew to the micropyle within 30 minutes to 2 hours after pollination indicating that a cross-incompatibility system is not the cause for low crossability among these species. By examining embryo sacs from P. intermedium × P. dilatatum, its reciprocal and P. intermedium × P. urvillei crosses, it was determined that gametes failed to unite in some crosses and this is a major reason for low crossability. 相似文献
12.
The effect of cut style and placental pollination on fertilization efficiency was studied for compatible Aechmea fasciata plants. These alternative in vitro pollination techniques resulted in lower penetration rates of the ovules by pollen tubes in comparison to pollination on
the stigma. An explanation was found in the intervention of the normal pollination process,through which less pollen-pistil
interactions were built up. After cut style pollination the percentage of ovule penetration by pollen tubes increased when
a longer style part was left at the ovary. Probably fewer factors that control pollen tube growth are present in the lower
style part. Pollen germinated on the ovules after placental pollination but only rarely penetration of the micropyle by a
pollen tube occurred. Activation of the ovary, induced by in vivo prepollination for 6 hours, and pollination two days after anthesis did not increase the fertilization percentage. Grafting
a style with active growing pollen tubes to ovules on the placenta (placental grafted style pollination) resulted in a higher
fertilization percentage. Pollen tube growth through the style was essential for pollen tube guidance to the ovules and penetration
of the micropyle.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
Sesbania sesban was amiable to controlled cross pollination when the emasculation and pollination operations were performed in the morning. A medium of 10% sucrose solution was found to be optimal for in vitro germination of the pollen grains. The pollen is quite tolerant of orthodox storage conditions enabling controlled crosses to be performed among accessions that flower in differing seasons of the year. 相似文献
14.
Cryopreservation of English walnut (Juglans regia L.) pollen 总被引：1，自引：0，他引：1
Summary Pollen from eight clones of English walnut (Juglans regia L.) was stored in liquid nitrogen (LN2) at-196°C for one year. Pollen was monitored for percent germination in vitro before being frozen. Pollen was frozen within two hours of anther dehiscence and subsequently at 24 hr intervals until germination assays indicated that the ability to germinate was lost. Survival after one year was evaluated by determining percent germination in vitro. Freshly collected pollen of only five of the eight clones survived LN2. By contrast, when the same pollen was held for 24 and 72 hr before freezing, pollen of all eight clones survived. Survival is correlated with moisture content (MC) of the pollen. Pollen samples with MC greater than 7.5% were killed by freezing in LN2. All pollen samples with MC between 4 and 7.5% survived as did most of the samples with MC between 3.2 and 4%. 相似文献
15.
Summary Pollen germination and pollen tube growth after self- and intra- and interspecific pollinations of annual [M. scutellata (L.) Mill., M. disciformis DC., and M. rigidula (L.) All.] and perennial (M. sativa L.) Medicago species were studied using a Carl Zeiss microscope with a fluorescence filter attachment.Self-pollination of self-fertile annual and intraspecific pollination of cross-fertile perennials were characterized by high pollen germination and rapid normal pollen tube growth. In contrast pollen germination percentages were very low and many pollen tube growth abnormalities occurred following interspecific pollination and self-pollination of self-sterile plants. The time period from pollination to fertilization for interspecific crosses was about double that following self-pollination of the annual species. However, fertilization occurred frequently following interspecific pollinations. Much of the sterility was due to factor(s) operating after fertilization.Cooperative investigations of the Kansas Agricultural Experiment Station, Dept. of Agronomy and the U.S. Department of Agriculture, Agricultural Research Service. Contribution No. 82-582-J- Mention of a trademark name or proprietary product does not constitute a guarantee or warranty by the U.S. Department of Agriculture, and does not imply its approval over other products that also may be suitable. 相似文献
16.
C. L. C. Lelivelt 《Euphytica》1993,67(3):185-197
Summary Pollen grain germination, pollen tube growth and micropylar penetration were investigated in intraspecific and intergeneric crosses involving Brassica napus L. ssp. oleifera (Metzg.) Sinsk. (oil-seed rape or fodder rape), xBrassicoraphanus Sageret (Raparadish) and diploid (2x) and tetraploid (4x) accessions of Sinapis alba L.(white mustard). For the reciprocal intergeneric crosses between B. napus and xBrassicoraphanus no effective barriers to pollen tube growth on stigmata or in styles were observed. The resulting low frequency of hybrid plants was mainly associated with a low rate of ovules with micropylar penetration per siliqua or with embryo abortion. Hybrid plants could be obtained without use of embryo rescue. In reciprocal crosses between B. napus and S. alba 2x or 4x incongruity barriers were observed on the stigma, in the style, and in the ovary resulting in a low frequency of ovules with micropylar penetration per siliqua. Open flower-pollination compared to bud-pollination generally was the more favourable procedure for pollen grain germination and pollen tube growth in crosses involving S. alba, but for micropylar penetration and seed set no differences were observed. Crosses between S. alba 2x () and B.napus () were found to result in a higher frequency of ovules with micropylar penetration as compared to reciprocal crosses or crosses with S. alba 4x. All reciprocal crosses between B. napus and S. alba 2x or 4x were unsuccessful when no embryo rescue was applied. Embryo rescue shortly after pollination, i.e. 2 to 5 days, however, resulted in hybrid seeds and plants, but only when applied to crosses between S. alba 2x () and B. napus (). The possible effects of the genome constitution, taxonomic distance and the parthenogenetic and parthenogenesis inducing ability of the parental genotypes on the observed malfunctions at the pre-and/or post-zygotic stage of the pollen grain-pistil interactions are discussed.Abbreviations DAP
Days After Pollination
- IAA
Indole-3-Acetic Acid
- kin
Kinetin 相似文献
17.
Effects of gamma irradiation on in vitro pollen germination of different Cucumis species 总被引：6，自引：0，他引：6
Summary Pollen grains of 14 Cucumis accessions were irradiated with 0, 1, 2, 3 or 4 kGy acute gamma rays and germinated in vitro directly afterwards. Pollen germination was significantly reduced by increasing irradiation dose for all species, except C. melo var. agrestis. Pollen tube growth was generally reduced likewise. Pollen of two C. anguria subspecies was most sensitive to irradiation. Sensitivity of the pollen with respect to pollen tube growth in relation to irradiation dose was inversely related to total DNA amount per nucleus. In vitro germination was not related to DNA amount per nucleus. Results show that the examined Cucumis species, especially C. melo var. agrestis, are sufficiently resistant to irradiation to be used as donor species for in vivo egg cell transformation of the cucumber. 相似文献
18.
Thomas Björkman 《Euphytica》1995,83(1):47-52
Summary Flowers of cultivated buckwheat (Fagopyrum esculentum Moench) often receive natural pollen loads of fewer than 10 pollen grains. The cultivated varieties also have high genetic variability. These observations raise the question of whether seed production in buckwheat is often limited by pollen delivery, and whether small increases in pollen load could result in gametophytic selection through pollen grain competition. In greenhouse-grown buckwheat plants, embryo sac penetration by pollen tubes was universal with 10 or more pollen grains. However, seed production increased with pollen load up to 30 grains per flower. Larger pollen loads, which intensify selection among gametophytes, resulted in more vigorous progeny. Seedlings produced from high pollen load (15–20 pollen grains) were larger (40% by weight) than those from low pollen load (5 pollen grains). These results are evidence that pollen grain competition can occur in buckwheat with benefits for progeny performance. 相似文献
19.
S. A. Bowes 《Euphytica》1990,48(3):275-278
Summary Three methods for the long-term storage of narcissus pollen were compared; anthers in glass vials held in a desiccator with calcium chloride at 2°C, and polypropylene straws containing either anthers or naked pollen immersed in liquid nitrogen. Pollen from all storage treatments showed 15–16% germination in vitro after 3 days, compared with 27.4% for fresh pollen. Seed set per pod using pollen stored for 3 days was comparable to that of fresh pollen. However, after 351 days, pollen from anthers at 2°C exhibited only 0.1% germination and failed to set seed whereas no further change in germination rate was recorded for pollen from the two liquid nitrogen treatments and seed set was still equivalent to fresh pollen. 相似文献
20.
Low temperature storage of pistachio pollen 总被引：3，自引：0，他引：3
Summary Pollen from four male pistachio (Pistacia vera L.) clones was stored at –196°C and –20°C for up to 12 months and tested for ability to germinate in vitro following a period of hydration at high humidity. Germination of fresh pollen was high (>80%) for each clone. At –196°C, pollen of cv. Peters survived freezing, storage and thawing with no loss of germinability; pollen of the other three clones had sharp declines in germination possibly attributable to cellular lesions incurred during freezing or thawing. When the relative humidity of the –20°C storage environment was maintained at or near 33%, Peters pollen had high rate of germination through 12 months storage. Without control of relative humidity, Peters pollen germination was high at 4 months, but declined at 12 months. Germination requirements became more exacting for pollen stored at –20°C for 12 months at suboptimal humidity conditions. Pollen of the other three clones did not tolerate storage at –20°C as well as Peters pollen regardless of the storage humidity environment. 相似文献