• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.348-352
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• 2013

This study was carried out to investigate the effect of sucrose, boric acid, and calcium nitrate in optimum pH and relative humidity on pollen germination and pollen tube growth of boxthorn (Lycium chinense M.). Medium containing 100mg/L of $H_3BO_3$ showed maximum pollen germination and pollen tube elongation, 64.8% and $920{\mu}m$. Additionally supplied calcium nitrate to the medium lowered pollen germination rate and pollen tube elongation. Here we report the optimum conditions for the pollen germination and pollen tube development was observed at 10% sucrose, 1.0% agar, pH 6.0, and 100% relative humidity.

• Journal of Plant Biology
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• v.39 no.4
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• pp.273-278
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• 1996

Arabidopsis mutants deficient in flavonoid and sinapate ester (tt4 and fah1-7, respectively) were evaluated in vivo and in vitro to study the possible role of flavonoid compounds in pollen tube growth. In vivo, we investigated pollen tube growth in the pistils of the mutants and wild type(Ler). The growth of pollen tubes was significantly different among the three genotypes. In the fal1-7 pistils, the tubes grew to a greater length relative to those of the wild type or tt4. To examine in vitro pollen tube growth, a solid medium was devised for pollen germination and subsequent growth. In vitro, the identical result was obtained; fahl-7 pollens developed the longest tubes and elongated most rapidly. Therefore, the growth response of pollen tubes to phenolic compounds was examined by adding quercetin or sinapate ester in various concentrations to the media. Quercetin enhanced both germination rate and tube growth in the pollens of the mutants and the wild type, especially in tt4. In contrast, sinapate ester inhibits pollen germination and pollen tube growth in three genotypes. These results suggest that flavonoids and related phenolic compounds have physiological role in the plant reproductive system.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.942-947
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• 2010

In the present study, pollen tube growth and fruit set in Asian pear ($Pyrus$ $pyrifolia$) were examined upon the mechanical damage on the stigma and style following the artificial pollination. When the upper middle part of style was cut off at 48 h after the artificial pollination, pollen tube grew to the middle of the style and the subsequent pollen tube elongation and fruit set normally occurred. When the style was cut off before the pollen tube reached the middle of the style, however, no pollen tube elongation and fruit set occurred. With the pollen tube elongation through the style, callose plugs at the basal part of the pollen tube were formed to the direction of the elongation at regular intervals. When the upper part of pollen tube attached pollen grain was cut off, however, callose plugs were formed defectively in the pollen tube, and the pollen tube opened and lost their turgor pressure. These facts might be the reason for the ceased or delayed pollen tube elongation and ultimately the failure of the fertilization.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.13-18
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• 2013

This study was conducted to examine the effect of temperature and relative humidity (RH) that might affect the pollen germination rate and pollen tube length in oriental melon. The experiment was performed using three cultivars namely 'Mallijangseong', 'Ohbokggul', and 'Joeundae' wherein environmental conditions were controlled by three different temperatures $15^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$ and also three RH levels 30%, 60%, and 90%. Based on the results in terms of temperature, true to all cultivars, plants exposed to $25^{\circ}C$ had the highest pollen germination rate while plants exposed to $15^{\circ}C$ had the lowest. Among the three cultivars, 'Mallijangseong' had the highest in terms of pollen germination rate, followed by 'Ohbokggul', and lastly was 'Joeundae' that showed the lowest germination rate. In the case of pollen tube length, pollen exposed under $35^{\circ}C$ showed the longest tube length, followed by pollen under $25^{\circ}C$, and pollen under $15^{\circ}C$ remarkably had the shortest tube length. Across the three cultivars 'Ohbokggul' had the longest pollen tube length. In the case of RH, pollen germination response among three cultivars depends on the humidity conditions but based on the results, there was no significant differences although high germination rate was observed in highest humidity condition. Between each cultivar, 'Ohbokggul' had the lowest pollen germination rate compared with 'Mallijangseong' and 'Joeundae' after exposure to different RH conditions wherein pollen germination showed significant differences among treatments. The pollen collected under 60% RH had the longest pollen tube length, followed by 30%, and the shortest was under 90% RH. In general, 'Ohbokggul' had the longest pollen tube length while 'Joeundae' had the shortest among the three cultivars.

• Korean Journal of Agricultural Science
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• v.5 no.1
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• pp.7-14
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• 1978

The experiment was carried out in order to choose fungicides which are proper to be used in flowering time of fruit trees. The effect of fungicides on pollen germination and pollen tube growth was investigated in vitro. The results obtained are as follows : 1. Difolatan-Wp, Lime-sulfur, Captan-Wp and Bordeaux mixture greatly inhibited pollen germination and pollen tube growth. 2. The effect of Daconil-Wp and Zimaneb-Wp on pollen germination and pollen tube growth was not so great as that of Difolatan-Wp, Lime-sulfur, Captan-Wp or Bordeaux mixture. 3. Polyram-combi-Wp, Topsin-Wp and Benlate-Wp did not affect pollen germination but these fungicides slightly inhibited pollen tube growth. 4. Polyoxin-Wp significantly increased pollen tube growth but did not show promotive effect on pollen germinaiton.

• Journal of Plant Biology
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• v.8 no.1_2
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• pp.19-23
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• 1965

Interaction occuring among the different Ca concentrations, pH and temperatures in the promotive effect of Ca in pollen growth was studied by using pollen from Crinum asiaticum and Cryptostegia grandiflora. Data for pollen tube elongation were found to be more indicative of representing the promotive action of Ca ion in pollen growth than those for pollen germination, and were served to evaluate the experimental results. The pollen growth increased as the concentration of Ca increase. The optimal pH range for pollen growth shifted from the lower pH to the higher as the concentration of Ca increase. The characteristic Ca effect was disappeared, and no pH effect at various ranges was observed when pollen grains were grown at the low temperature(8$^{\circ}C$). The Ca effect became quite pronounced if temperature were raised. The Ca effect became even mroe striking if the condition was in higher pH ranges (weak alkaline). Higher pH ranges were found to be more favorable for the Ca action, whereas higher temperature was required to bring about more pronounced Ca effect. Thus, the longest pollen tube was obtained with the highest pH, temperature adopted for the medium supplemented with Ca in the present experiment, and the shortest tube with the lowest temperature applied at the highest pH. Pectin synthesis in pollen tube was considered as a metabolic process, whereas Ca binding in pectin of the pollen tube wall as non-metabolic in nature. Disappearance of Ca effect at the low temperature was probably brought about by blocking the metabolic synthesis of pectin, and nonmetabolic Ca binding seems to take place more extensively with higher concentrations of Ca and at higher pH levels than the lower.

• Journal of Plant Biology
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• v.9 no.1_2
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• pp.17-21
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• 1966

The mutual relationships of boron, Ca and sucrose were studied in relation to in vitro pollen growth and pollen bursting, by using conventient pollen from Crinum asiaticum for experiment. Crinum pollen are paticularly sensitive to Ca. Addition of very small amount of boron to cultural media was apparently synergistic to the action of sucrose and Ca in pollen germination and tube elongation. This action was extended to a higher level of boron concentraton. Combined application of boron, Ca and sucrose always gave the better results in pollen growth and protection against pollen bursting much more than when used singly. This indicated that there is a direct relationship between better growth of pollen and increased rigidity of pollen cell wall. A higher level of Ca concentration tended to increase bursting rate of pollen grains and decrease that of pollen tubes, while boron always depressed the rate of bursting. This was considered due to increased failure in pollen germination at high level of Ca that favors pollen tube elongation. The fact that Ca show an antagonistic effect on the suppressive action of high level of boron in pollen growth and shows different effect in response to pollen bursting from boron, suggested mode of Ca and boron action in the presence of sucrose is quiate different, although to increase in rigidity of pollen cell wall by them is in common nature. It was postulated therefore that Ca acts on pectins of pollen cell wall largely as "non-metabolic" and boron as "metabolic" promoter is pollen growth and protecting pollen bursting, since boron and Ca have common nature in strengthening the pollen cell wall but act differently.but act differently.

• Korean Journal of Plant Resources
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• v.3 no.2
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• pp.123-128
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• 1990

In every reciprocal crosses of self pollination, interspecific pollination through ordinary stigma pollination of L. longiflorum and $L.{\;}{\times}{\;}elegans$, pollen vigorously germinated in stigma, and pollen tube was growing. But, 5 days after pollination, pollen tube stopping their growth in the same style as was observed in the cross of self pollination and interspecific pollination. Intrastylar pollination of $L.{\;}{\times}{\;}elegans$ and L. longiflorum passed stylar cannal through the basal part of styles. But, pollen tube that was growing to the ovule of the ovary was extremely small. In morphogical observation of ovary 10 days after pollination, it was observed, that every reciprocal crosses of L. longiflorum ${\times}$ L. ${\times}$ elegans was fertilized through intrastylar pollination, so that this technique was used to overcome cross incompatibilities.lities.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.389-393
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• 2002

Effects of environmental factors on in vitro pine pollen performance were investigated. Pinus densiflora and P. rigida pollen grains collected at Mt. Kwanak, Korea were used. Three environmental factors, such as pollen storage temperature, pollen culture temperature and nutrient condition in medium, were tested. To determine the storage temperature effects on pollen viability, pine pollen was stored at $-70^{\circ}C$, $-12^{\circ}C$, $4^{\circ}C$ and $22^{\circ}C$. Pollen viability was substantially extended at the storage temperatures of $-12^{\circ}C$ and $4^{\circ}C$ for more than 300 days. To elucidate the culture temperature effects on pine pollen germination and tube growth, pollen grains were cultured at the temperatures from $5^{\circ}C$ to $40^{\circ}C$ at $5^{\circ}C$intervals. The germination rate and tube growth were highest at $25^{\circ}C$ and decreased above $30^{\circ}C$. To investigate boron and sucrose effects on pollen tube growth, the pollen was cultured at different sucrose and boric acid concentrations. Germination rate was optimal in germination medium containing 3 or 5$\%$ sucrose with 0.01 $\%$ boric acid. These results indicate that the pine pollen can be stored for considerable length of time without noticeable loss of viability at storage temperature below or near $0^{\circ}C$. Optimal germination medium conditions were established for pine pollen. Therefore, pine pollen can be used for many biological and environmental monitoring researches.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.184-192
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• 2016

This study was carried out to investigate the effect of temperature ($15{\sim}40^{\circ}C$) and the spraying plant growth regulators ($GA_{4+7}+BA$ and prohexadione-calcium) during full blooming on pollen germination and pollen tube growth of the commercial apple cultivars ('Fuji' and 'Tsugaru') and apple cultivars bred in Korea ('Chukwang', 'Gamhong', 'Hongan', 'Honggeum', 'Hongro', 'Hwahong', 'Hongso', 'Summer dream' and 'Sunhong'). Pollen germination and pollen tube growth were increased with increasing temperature from 15 to $25^{\circ}C$, but high temperature over $30^{\circ}C$ inhibit those. The apple cultivar bred in Korea that shows the highest value on pollen germination and pollen tube growth at over $30^{\circ}C$ was 'Sunhong'. The spraying $GA_{4+7}+BA$ increased pollen germination and pollen tube growth than control, but that effect was not show at $40^{\circ}C$. The spraying prohexadione-calcium was not affect to pollen germination and pollen tube growth. In conclusion, if the air temperature during full bloom of apple tree rises about $30{\sim}35^{\circ}C$, the spraying $GA_{4+7}+BA$ after artificial pollination will be good to increasing fruit set.