• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.290-294
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• 2007

Interspecific hybrid seedlings by artificial crossing of Genus Quercus (Q. serrata, Q. dentata, Q. mongolica var. crispula, Q. aliena) were planted at nursery in Tottori University. Seedlings of hybrids by natural crossing(Q. fabri and $Q.{\times}mccormickii$) were selected and planted at Hiruzen district in Tottori University. Artificial interspecific hybrid $F_1$ and natural hybrid $F_1$ bloomed when they were 4 years old and 3 years old, respectively. The pollen fertility and seed viability were investigated from the bloomed individuals in 2001. The germination percentages of the pollens of artificial interspecific hybrid were more than 84% except one individual, and the extension of pollen tubes was normal. The normal seed percentages of artificial interspecific hybrid were more than 90% similar to parents. Germination percentages of normal seed of natural crossing family were more than 64%, respectively, and selfed offsprings of Q. fabri, and $Q.{\times}mccormickii$ hade high reproductive ability.

• Korean Journal of Medicinal Crop Science
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• v.4 no.3
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• pp.231-235
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• 1996

The experiment was conducted to determine pollen morphology of Chinese peony and its germination. The results were obtained as following ; Pollen shpae was usually large ellipse and the pol­len germination rate of Eui-seong Peony line was 71% which was lower than that of other Peony lines. In a bud, the pollen began to be observed on $7{\sim}9days$ before flowering and as getting on for flowering time, normal pollen and germination rates were higher. The pollen germination and elongation beganat 30 minutes after incubation on artificial medium and were completed after $2{\sim}3\;hours$. As the storage time went on, the pollen life span was shortened. The germination rate was 51% at 8 days-storage of room temperature. The germination rate was 48% ad 43% at 95 day-storage in $0^{\circ}C$ and $-15^{\circ}C$, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.5 no.1
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• pp.87-93
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• 1969

A study has been made on phenomena of fertilization, hair genesis, and development of such forma of cotton flower as Mok Po 5, Red Leaf, Paymaster, Acala 1517w. 1) The pollen occurs to germinat at 4 hrs after its pollination and reaches the base of style 10 hrs. later, when 18 hrs elapsed, it gets enter at micropyle passes through placenta. 2) There may remain only one synergid as another one is occupied by pollen tube when it enters micropyle. 3) The fertilization completed at 18-48 hrs. after pollination. It was observed that Mok Po5 is the fastest, somewhat slower in Red Leaf and the slowest is the case of Paymaster in its speed. 4) Wool hair is formed by development of daughter cell which is. due to epidermal cell division' it starts its way right before blooming. 5) Wool hair is the most in its number covering about 60-80 within one hour ofter pollination and finishes its forming within 4-6 hours. The number is more abunbant at basal portion of ovule and rather at outer surface than at inner one of it. 6) The average length of wool hair checked at different time limit is as follows. 2.7-8.3$^{\mu} m$ 1 hr after pollination. 43.3-263.7$^{\mu} m$ 24-48 hrs. after pollination. The growth speed both of Mok Po 5 and Red Leaf get nearly same value but Paymaster is somewhat slower in its speed.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.285-292
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• 2012

Self-incompatibility (SI) system is a genetic barrier that prevents self-fertilization and promotes cross-pollination among different S genotypes. In many of these species, SI is controlled by a single genetic locus known as S locus, which prevents the fertilization by pollen with same locus. S RNases are the products of the S-locus expressed in the stylar tissue of Fuji Apple with gametophytic self-incompatibility system. This study investigated the various types of chemicals in order to select more effective inhibitors and activators. The effect on the inhibition of S RNase of Fuji apples was investigated $in$ $vitro$. The result showed that the enzyme activity was reduced 24.3% by Iron(II) Sulfate, significantly. $In$ $vitro$ studies of pollen growth tube showed that pollen tube growth had a higher germination rate (90%) in 10% Sucrose than in 2% sucrose extension medium. Data on the fruit set of apples treated with inhibitor and activator. Double application of $A^+$(Apple Plus, ISTECH Co. Ltd.,)+Vitamin B6 had the highest central fruit set as 86.1%(Andong). One time application of $A^{++}$Vitamin B1 in Yeongju obtained the highest central fruit set (91.9%).

• Horticultural Science & Technology
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• v.19 no.3
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• pp.373-377
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• 2001

This study was conducted to find optimum pollination methods for overcoming pre-fertilization incompatibility in interspecific crosses between L. longiflorum 'Gelria' (LG) and L. cernuum (LC). In cross combination of $LC{\times}LG$, the survival rate of the ovaries was higher in the cut style pollinations than in normal stigmatic pollination. Among the various cut style pollination methods, pollination after cutting the styles 2 3mm length above the ovary and top of the ovary were the most effective ones. No ovaries and ovules survived in cross pollination of $LC{\times}LG$. In self-pollination of LG and cross pollination of $LC{\times}LG$, pollens germinated on the stigma by 12 hours and reached to the ovules by 90 hours after pollination. However, in the cross pollination of $LC{\times}LG$, pollen tubes elongated very slowly until 48 hours after pollination and a lot of deformed tubes were observed in the styler canal having swelled tube tip and irregular heavy callose deposition. The pollination time after anthesis also affected on the survival rate of ovaries and ovules showing the best result when pollinated on three days after anthesis. Stigma exudate promoted slightly the enlargement of ovaries, but the survival rate of ovaries and ovules was not increased.

• Journal of Plant Biology
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• v.3 no.1
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• pp.16-25
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• 1960

HARN, Chang Yawl (Chonnam U. Kwangju, Korea): Siudies on the dimorpism of the Perisicaria senticosa Nakai-Kor. jour. Bot. 3(1) 16-25 During his researches regarding the morphological and physiological properties of Polygonecenae, the author has found that the species, Persicaria senticosa, aiso, besides the heterostylous plants of Polygonum family, Fagopyrum esculentum, and Persicaria japonica which was recently verified by the author as dimorphic, shows the typical floral structure of heterostylism, the description of which is not found in taxonomical works. Further research on this species have revealed that this plant, despite pressessing characteristic structural dimorphism, does not exhibit even the slight signs of heterostlylous properties physiologically. This is a deviation from the usual behavior of normal heterostylous plants. What is interesting is the fact that the physiological behavior of this species is quite contrary to that of P. japonica which is considered to be the most highly specialized dimorphic plant. Thus it is assurred that if some species of this family had taken a heterostylic form in its course of development from autogamy to allogamy, P. seoticosa would be the least differentiated type of dimorphic forms among the three heterostylous plants, including buckwheat, of this family. The results obtained in this experiment are summarized as follows: 1) P. senticosa has two forms of flower, one, long style-short stamened; the other, short style-long stamened. Not only conspicuous is this primary difference, but the secondary difference, such as pollen grain size, is noticeable between long and short styled individuals, thus expressing structurally the definite trait of a dimorphic plant. 2) Structural alteration of floral parts towards dimorphism has preceeded far less in comparison with those of the P. japonica and F. esculentum. 3) Elaborate studies on fertility reveal that this species does not show the slightest sign of the physiological characteristics of dimorphic plants. In other words, regardless of the modes of combinations, legitimate and illegitimate, fertilization and fruit setting flourish unimpaired. 4) Growth of pollen tubes apparently parallels the results in the fertility, tubes reaching ovary approximately 30 minutes after pollination both in legitimate and illegitimate combinations. Pollen tube penetration appears to be comparatively rapid. 5) A slight difference in the growth of pollen tube seems to exist between legitimate and illegitimate combinations, legitimate union giving slightly faster tube penetration. 6) In the present experiment it was clarified that P. senticosa, known to possess one form of flower in taxonomy, is in reality dimorphic plant having two of flowers. Although this species is definitely heterostylous in floral structure, physiological evidence and pollen tube behavior show that the differentiation of this plant toward the dimorphism has apparently proceeded slightly except for some parts of floral organ. In ordinary heterostylous plants it is a matter of common occurrence that when illegitimately cmbined, there is poor or no fertility, Contrary to the universal property of heterostylous plants, no difference is observed in the fertility and pollen tube growth between the legitimate and illegitimate combinations in the case of P. senticosa. Compared to the P. japonica and F. esculentum, which are supposed to have undergone high degree of dimorphic differentiation, it is an unavoidable conclusion that P. senticosa has not yet developed as a heterostyle plant except for some of its floral parts. If P. japonica is assumed to be the most differentiated type of hetenostylous plant, thenthe P. senticosa would be regarded as the primitive, retaining still the self-fertile nature so common to the Polygonum genus. In nature, however, this plant has a better chance to be pollinated legitimately owing to the two forms of flowers than to be pollinated illegitimately. The author is indebted to Dong Chul, Kim as well as other members of the Department of Plant Breeding and Genetics of Chonnam National University for their efforts out the laborious experiments during the course of the present studies.

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.119-125
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• 2015

Interspecific crosses between rapeseed (Brassica napus L.) and chinese cabbage (B. campestris var. pekinensis Makino) and turnip (B. rapa L.) were made in order to examine the cross possibility and morphological phenotype of $F_1$ hybrid. The growth of pollen tube of cross between rapeseed and chinese cabbage was more rapid than cross between rapeseed and turnip. Silique formation and seed setting in silique were relatively high in the cross between rapeseed and chinese cabbage. The percentage of silique set from interspecific cross between rapeseed and chinese cabbage was 90.6% and higher 23.3% than the percentage of silique from interspecific cross rapeseed and turnip. The average number of seed per silique obtained from the cross rapeseed and chinese cabbage, and rapeseed and turnip reached 15.5 and 11.6, respectively. The morphological phenotypes of $F_1$ hybrid plants obtained from seeds in the cross between rapeseed and chinese cabbage resembled rapeseed mainly, but leaf length and leaf width were increased. The size, shape and lobation of leaves of $F_1$ hybrid plants from interspecific cross between rapeseed and turnip were intermediated between their parent species, but color of leaves was dark-green.