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1.
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
2.
Blueberry (Vaccinium section Cyanococcus, family Ericaceae) is a shrub that produces multiple-seeded berries in which only a fraction of the ovules
develop into viable seeds. A recessive yellowleaf marker gene was used to evaluate the efectiveness of a single pollination
versus multiple pollinations in producing seeds in Vaccinium elliottii Chapm. A multiple-pollination experiment was conducted to see if the first pollen applied or the second produced more progeny,
and to see if multiple pollinations increased the number of seedlings produced. Flowers of diploid yellowleaf Vaccinium elliottii were pollinated from one to four times at daily intervals. Pollen from redleaf and yellowleaf plants was used to produce
two types of seedlings that could be distinguished visually. Generally, percent berry set, seeds per berry, and seed germination
were not increased by multiple pollination. After multiple pollination, the pollen applied first always produced the most
seedlings. Prior pollination greatly reduced seed set from subsequent pollination, but subsequent pollination caused little
or no decrease in the number of seeds set by the first pollination.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
Summary Using the finger nails to remove most of the petals is a fast method of preparing apple flowers for hand pollination in the balloon stage. Such flowers still appeared quite attractive to insects; left to open pollination, the seed set per flower averaged two thirds of that of similarly treated, but hand-pollinated flowers. With the aid of marker pollen of scab or mildew resistant donors and the subsequent screening of the seedling progenies for resistance, it was shown that the stray pollen was responsible on average for one of every three seeds formed by unbagged depetalled and hand-pollinated flowers. 相似文献
4.
Leena Pietilä 《Euphytica》1995,84(2):127-131
Summary Pollination experiments were carried out on ulluco (Ullucus tuberosus), known as a very poor seed producer. All the clones used were diploids. The effect of self-vs. cross-pollination was studied in Experiment 1. Caged selfpollinated flowers produced no seeds. Different clones produced seeds in 0–8% of caged cross-pollinated flowers and in 5–19% of cross-pollinated non-caged flowers. Ulluco is thus basically an outbreeder.Experiment 2 studied whether seed set is limited by pollen availability. Total seed number per inflorescence number did not differ between plants treated with supplemental pollen and control plants; pollen availability thus did not limit seed set. The treated plants, however, produced more seeds in cross-pollinated than in other flowers on the plant, and the control flowers on treated plants produced fewer seeds than those on the control plants. In the treated plants, resources may have been allocated to artificially cross-pollinated flowers at the expense of other flowers. In some clones, seed set after artificial cross-pollination was at a level practicable for breeding work. 相似文献
5.
Summary The impact of cross pollination 30 h, 4 h, and immediately prior to self-pollination, and self-pollination 2, 4, 8, 12, 24 and 30 h prior to cross-pollination was assessed for pollen tube number per style, seed number per siliqua, and proportion of self-seed (sibs) per siliqua, in two inbred lines of brussels sprout. Pollination procedure had a marked effect on the amount of sib-and hybrid seed produced. Cross pollination 30 h prior to self-pollination produced significantly greater numbers of sib progeny, as did self-pollination 8–12 h before cross pollination. Prior application of self pollen reduces the number of pollen tubes in the style. The results of this experiment suggest that self-incompatibility in brussels sprout could better be assessed by self-pollination with a subsequent cross pollination 8 h later, and the determination of amounts of sib and F1 hybrid seed per siliqua. 相似文献
6.
Summary A controlled environment study was undertaken to clarify the factors responsible for poor seed set and to study seed development, ovule degeneration and seed abortion, both morphologically and cytologically, in three Japanese cultivars of white clover. Although the mean number of ovules per floret was 4.2–5.1, the average number of seeds per floret was found to be only 2.3–2.7. Microscopic examination of carpels from 0 to 28 days following floret maturity and pollination showed that 26–33% and 8–17% of the total seeds lost occurred within the first three days and the third through fifth day following pollination, respectively. Beyond this period occasional seed abortion was observed at all stages of seed development, but this represented a very small proportion (2–7%) of the total seeds lost.A stain clearing technique was used to examine the cytoplasmic state of the embryo sac in intact, unfertilized, mature ovules and embryos of the ovules at 3 and 5-day periods following pollination. It was found that 20–22% of unfertilized and matured ovules were sterile, suggesting that ovule degeneration before fertilization was the major cause for the high percentage of seeds lost within a 0 to 3-day period following pollination. Cytological observations revealed that abortion of developing seed was due to a sudden arrest in embryo growth and that the early development of the embryo of such aborting seed was normal. Either nutrient shortage or meiotic irregularities may be the cause for high ovule sterility or post-fertilization abortion of developing seeds. 相似文献
7.
Summary The effects of different pollination techniques, with and without emasculation and delayed pollination, were investigated to find the conditions for maximum seed set after self-pollination and intraspecific and interspecific crosses of Brassica oleracea var. acephala. The results indicated that the pollination conditions achieving maximum seed set vary with the type of pollination. After controlled self-pollination, the best seed set occurs in bud 3 to bud 10. For the intraspecific cross, the youngest flower and the oldest bud produced the largest number of developed ovules but bud pollination was productive to bud 8. The yields from these two pollination types were best when the female parent was not emasculated. In the interspecific cross with B. campestris cv. Marco the best results came from the youngest flowers and the oldest buds subjected to the standard practice of pollinating directly after emasculation. Possible reasons for these effects are discussed. 相似文献
8.
Summary Flatpea (Lathyrus sylvestris L.) is a potentially valuable forage legume, but it contains high levels of 2,4-diaminobutyric acid (A2bu), a compound that can have adverse effects on some animals, including rats and poultry. This study evaluated intercrossed pollination methodology needed for cultivar improvement and characterized intercrossed progeny for A2bu concentration. Pollen germination on an artificial medium, using pollen collected during different stages of flower development, was used to identify appropriate stages for flower emasculation. Pollen dehiscence occurred at an early-bud stage when petal color was first evident. Slightly more mature buds contained pollen with substantially higher in vitro germination than pollen from early-bud stage flowers. Lines that produced high numbers of seeds per pollination were identified from crosses between flatpea accessions. Cross-pollination resulted in significantly higher seed set than selfing. Pollination using caged honeybees was the most efficient method of hybridization, although the degree of inbreeding in bee-pollinated plants could not be determined. Intercrossed progeny produced by honeybee pollination contained a lower mean concentration of foliar A2bu than the mean for flatpea accessions.Abbreviations HPLC
high performance liquid chromatography
- OPA
ortho-phthalaldehyde 相似文献
9.
‘Thermally aided pollination’: A new method of breaking self-incompatibility in Brassica oleracea L.
Summary Application of heat during self-pollination of open flowers by means of an electric mini soldering iron resulted in seed set in self-incompatible Brassica oleracea varieties. Temperatures of 60, 70 and 80°C were tested. Compared with bud-pollination, in some cases the so-called thermally aided pollination (TAP) method, gave a considerably higher seed yield at 70 and 80°C. In view of the ease and rapidity of TAP it should be ascertained how far this method can replace bud-pollination in maintaining inbred lines. The possible mechanism behind the TAP response is briefly discussed. 相似文献
10.
J. H. Heering 《Euphytica》1993,74(1-2):143-148
Summary The reproductive biology of Sesbania sesban, S. goetzei and S. keniensis (Leguminosae; Papilionoideae) was studied. Fifty percent flowering was observed at 102 to 153 days after germination for S. sesban accessions; 96 to 146 days for S. goetzei and 131 to 176 days for S. keniensis accessions. Flowers opened in the afternoon and remained fresh for 2–3 days. Bee species including Xylocopa sp., Apis mellifera, Megachile bituberculata and Chalicodoma sp. visited the flowers. Hand pollination experiments showed that all three species were self and cross compatible. The percentage of fully developed seeds was greater in pods formed after cross pollination compared to self pollination. No evidence was found for stigmatic or stylar self incompatibility. Outcrossing is probably the common method of reproduction under natural conditions, although in isolated trees substantial seed set by selfing might occur. Pod production under natural conditions was 34% for S. sesban; 49% for S. goetzei and 39% for S. keniensis. Considerable variation was found in pod production under open pollination between accessions of the same species. Selective abortion was observed within pods, with more mature seeds formed at the distal end of the pod. 相似文献
11.
Summary Broccoli (Brassica oleracea L. var. italica) progenies grown from seed obtained by greenhouse budpollination (BP), open-flower self-pollination (OS), open-flower self-pollination with ether treatment of the stigma (OSE), and cross.pollination (CP) were compared in the field. For plant height, plant weight, head diameter, and head weight, BP resulted in the lowest values, OS and OSE were intermediate, and CP gave highest values. BP was highest, OS and OSE intermediate, and CP lowest for days to head emergence and days to harvest. Differences between OS and OSE were slight and all were non-significant for the 7 lines with complete data, but were significant for plant weight and head diameter when 20 lines were analyzed by the unweighted means method. The comparison BP versus OS-OSE was non-significant for plant height in both analyses and for head weight in the 7-line analysis only. In a second experiment using only BP and OS, and omitting days to head emergence, trends were similar but only the effects on head diameter were statistically significant. In the greenhouse, BP produced much more seed than either OS or OSE, and CP produced more than BP. Treatment of the stigma of open flowers with ether to overcome self-incompatibility did not result in greater seed production. Weight/100 seeds was higher in CP but did not differ among the three self-pollination methods.Technical Paper 5089, Oregon Agricultural Expriment Station. 相似文献
12.
Summary The effect of gibberellic acid (GA3) was studied on a wide range of crosses between various garden roses and two hardy breeding lines. Although there were fewer seeds per fruit, fruit set was higher in most crosses when GA3 was applied to the stigma at the rate of 250 ppm ten days after pollination. However, higher fruit set did not result in more seeds per pollination for many crosses and seemed to be related to the degree of male parentage. Both parents used had a major effect on pollination success. Recently developed Rosa cultivars have a narrow genetic base and the use of distantly related cultivars as parents would possibly give a high seed set and greater numbers of progeny.Contribution No. 335/90.08.01R, Experimental Farm, L'Assomption; Contribution No. Ro 44, Research Program Service, Ottawa. 相似文献
13.
Radovan Marinković 《Euphytica》1992,60(3):201-205
Summary Interactions of seven bio-morphological characteristics of sunflower (head diameter, number of flowers per head, number of seeds per head, 1,000-seed weight, volume weight, kernel content in seed, oil content) and their correlations with seed yield per plant were examined. The path-coefficient analysis provided information about direct and indirect effects of the examined characteristics on seed yield per plant. The correlation coefficients were positive and highly significant. The highest direct positive effect on seed yield per plant was exhibited by the weight of 1,000 seeds. Head diameter, volume weight and kernel content had a direct negative effect on seed yield per plant. 相似文献
14.
Interspecific hybrids were produced from reciprocal crosses between Brassica napus (2n = 38, AACC) and B. oleracea var. alboglabra (2n = 18, CC) to introgress the zero-erucic acid alleles from B. napus into B. oleracea. The ovule culture embryo rescue technique was applied for production of F1 plants. The effects of silique age, as measured by days after pollination (DAP), and growth condition (temperature) on the
efficiency of this technique was investigated. The greatest numbers of hybrids per pollination were produced under 20°/15°C
(day/night) at 16 DAP for B. oleracea (♀) × B. napus crosses, while under 15°/10°C at 14 DAP for B. napus (♀) × B. oleracea crosses. Application of the ovule culture technique also increased the efficiency of BC1 (F1 × B. oleracea) hybrid production by 10-fold over in vivo seed set. The segregation of erucic acid alleles in the self-pollinated backcross
generation, i.e. in BC1S1 seeds, revealed that the gametes of the F1 and BC1 plants carrying a greater number of A-genome chromosomes were more viable. This resulted in a significantly greater number
of intermediate and a smaller number of high-erucic acid BC1S1 seeds. 相似文献
15.
Summary Phytotron experiments have been carried out to study the effect of different temperatures on the seed set of tetraploid freesias during the raising of the plants and at the time of flowering and pollination.The effect of a relatively low temperature during the growth period is reflected in a comperatively greater number of flowers as a result of an increase in number of ramifications of the peduncle. This sometimes promotes the seed yield notwithstanding that the lower temperature reduces the fertility of each seperate flower. It is clearly proved that the temperature during flowering and pollination affects the fertility of the flower and the ultimate seed yield of the plant. Experiments in our phytotron showed 14°C during the growth period and 20°C at the time of pollination to be the optimum combination for a good seed yield.The effect of a lower night temperature was generally favourable, particularly so when measured by the number of seeds per pollinated flower. 相似文献
16.
Koshun Ishiki 《Euphytica》1991,55(1):7-13
Summary In order to promote cytogenetical studies on Oryza glaberrima (2n=2x=24), I produced primary trisomics in the progeny of the autotriploid. When the autotriploid was pollinated with the diploid, 136F1 seeds (5.8% of the number of spikelets pollinated) were obtained. The numbers of chromosomes of 31 surviving progeny varied from 24 to 28, with plants having 2n=25 occurring at the highest frequency (34.4%). The primary trisomics differed from one another as well as from the normal disomics in many aspects. The differences were attributed to a single extra chromosome in each trisomic type. Nine primary trisomics were classified into 8 types on the basis of morphological and reproductive features. Seeds were obtained from all primary trisomics except for Type D by self pollination, open pollination or pollination with the disomics. I was able to maintain 7 types of primary trisomics by seed propagation. The primary trisomics which are capable of expressing subtle genetic dissimilarities should be useful for studying the relationship between the two cultivated species of rice at the level of individual chromosomes. 相似文献
17.
T. Hodgkin 《Euphytica》1980,29(1):65-71
Summary In a study of partial self-compatibility in Brassica oleracea, flower number, seeded siliqua and seed production were recorded on self-and cross-pollinated inflorescences of the progenies of a half diallel between six in bred Brussels sprout plants homozygous for the same moderately recessive incompatibility allele S45.On both self-and cross-pollinated inflorescences significant amounts of additively controlled genetic variation were found for seed set per flower. For cross-pollinated inflorescences this was also the case for the two components of seed set, seeded siliquae per flower and seeds per seeded siliquae, but for self-pollinated ones only seeded siliquae production showed significant additive variation. Considerable heterosis and gene interaction were always present and a simple additive dominance model did not explain the variation.Two of the parents transmitted lower levels of partial self-compatibility to their progenies and, in one of these, dominant genes appeared to be responsible. The most important feature determining the production of self seeds was found to be the number of flowering sites at which the incompatibility mechanism failed rather than the number of seeds produced at each site. 相似文献
18.
Summary With Brussels sprouts, Savoy and white cabbage different pollination methods were compared for their efficiency in producing self-seed. Besides bud pollination (BP), also the steel brush and electric aided pollination (EAP) method were used. The steel brush method was found to be considerably less effective than BP and EAP. With BP the mean number of seeds per fruit was higher than with EAP. However, this was compensated for by a higher percentage of fruit setting with EAP. Although the clones responded differently to EAP and BP, the total self-seed production per pollination was the same with either method.With EAP open flowers can be selfed. This implies that EAP can be carried out by untrained people in about 60% of the time experienced bud-pollinators require. 相似文献
19.
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
20.
Summary A technique for artificial cross pollination in clove is described. This involves emasculating flowers two days before anthesis, and pollinating four days later. Following this procedure a seed set of approximately 25% can be expected. 相似文献